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1

Regularities of Crystallization Heat Release During Solidification of Alloyed Cast Irons

Aftandiliants Y., Gnyloskurenko S., Meniailo H., Khrychikov V., Lomakin V.

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 1

110--117

EN

The chemical composition of alloys plays an important role at their crystallization and influences the solid phase formation, and thus, microstructure and properties. The present paper studies the release of the heat of crystallization of alloyed wear-resistant cast irons in order to determine the quantitative patterns of the chemical composition influence to the kinetics of crystallization. The differential thermal analysis was applied to get the data of heat release, its rate at cast iron temperature decrease. The normalized dependence of the amount of crystallization heat over time was obtained. The main temperature parameters were analyzed and four stages at irons crystallization were established and characterized with their duration and released heat. The multiple correlation analysis allowed considering a numerous physical and chemical factors and distinguishing their role at crystallization of irons. As a result, the quantitative regularities are determined of influencing the content of alloying elements, impurities and carbides on a heat and time of crystallization at the different stages of solidification, which are of great importance in developing alloyed irons with required quality and properties.

2

Tribological Studies on AlCrFeCuCoNi High Entropy Alloy Surface Coated on Ti-6Al-4V Using Plasma Transferred Arc Technique

Prabu G., Duraiselvam Muthukannan

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 2

409--420

EN

AlCrFeCuCoNi high entropy particles were alloyed on Ti-6Al-4V surface using Plasma transferred arc (PTA) process. PTA alloyed surfaces were investigated for their phase formation, microhardness improvement and wear behaviour. The various wear mechanism and their corresponding surface roughness were studied. The results revealed that the dual phase of BCC and FCC microstructure along with some intermetallic compounds were grown in the alloyed region through the PTA technique and good metallurgical bonding of the alloyed region with the base material were achieved. The PTA alloyed region exhibited a hardness of 718 HV0.2 which is 2.2 times higher than the hardness of base material. The PTA alloyed samples showed higher wear resistance due to the solid solution strengthening as the HEA has high entropy of mixing that leads to the reduction of free energy of the alloyed region. It exhibited better interconnection of the coated material and superior metallurgical bonding to the base material. Frictional heat produced during the wear test has promoted the formation of FeO, Cr2O3, CuO, NiO and Al2O3 oxide film on the PTA alloyed sample. These oxide films act as a barrier between two mating surfaces and improve the tribo performance of the PTA alloyed sample.

3

Wpływ stanu strukturalnego na skutki obróbki laserowej stali o różnym składzie chemicznym. Cz. 3, Stale narzędziowe

Berkowski Leopold

Obróbka Plastyczna Metali

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2019

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T. 30, nr 4

307--326

PL

Praca stanowi trzecią część większej całości, przyczynkowych badań w zakresie technologii laserowych stali o różnym składzie chemicznym. W pierwszych dwóch częściach omówiono skutki obróbki laserowej stali węglowych [1] i konstrukcyjnych stopowych [2]. W pierwszej części pracy wykazano, że wzrost zawartości węgla powoduje wyraźny wzrost twardości zahartowanej laserowo stali, wpływa na kształt warstwy oraz na charakter nieciągłości powstałych w strefie przetopionej. W badaniach pro-wadzonych w części drugiej potwierdzono znaczenie udziału węgla oraz oceniono wpływ składników stopowych na odpuszczalność stali. Wykazano ponadto, że obróbka laserowa niszczy warstwę dyfuzyjną, azotowaną. Badania, których wyniki zawiera niniejsza praca są owocem współpracy trzech ośrodków badawczych: Instytutu Fraunhofera IPT – Aachen, Instytutu Maszyn Roboczych i Transportu Politechniki Poznańskiej oraz Instytutu Obróbki Plastycznej w Poznaniu. Praca zawiera wyniki badań skutków obróbki laserowej stali NC11LV w stanie wyjściowym (wyżarzonym) i zahartowanym z różnej temperatury, także w warstwach położonych w różnej od siebie odległości. Ponadto praca zawiera ocenę jakości stopowania, z pomocą proszków o różnej zawartości składników stopowych stali przeznaczonej na narzędzia kuźnicze. Struktura wyjściowa stali NC11LV była martenzytyczna z niewielką ilością austenitu szczątkowego po hartowaniu z temperatury 1020oC oraz zawierającą austenit z niewielką ilością węglików po hartowaniu z temperatury 1150oC. Stwierdzono, że twardość stali w strefie przetopionej (około 500 HV0,1) jest zbliżona do twardości stali NC11LV zahartowanej z temperatury 1150oC, a w strefie przejściowej rozrzut wyników pomiarów twardości jest nieregularny; bardziej w strefie hartowania wstępnego z temperatury 1020oC. Natomiast wpływ prędkości przemieszczania się wiązki światła lasera na stan strefy przypowierzchniowej próbki jest podobny jak w pracach [1–2]; wzrost prędkości powoduje zmniejszenie „parametrów” warstwy. Z badań wynika, że obróbka laserowa niezależnie od stanu wyjściowego (temperatury hartowania) nie po-woduje korzystnych zmian warstwy wierzchniej stali NC11LV. Pozytywne rezultaty uzyskano natomiast w badaniach nad technologią stopowania narzędzi kuźniczych ze stali WCL. W próbkach stopowanych z pomocą proszku Mo/VC wyznaczono temperaturę odpuszczania stopowanych warstw (600oC), wyższą od temperatury odpuszczania stali szybkotnących. W badaniach nad doborem technologii oceniono piętnaście wariantów, w których zastosowano trzy grupy proszków o różnym składzie chemicznym WC/Co, WC/Co/Cr i Mo/VC w odpowiednim stosunku składników i wielkości dozowania. Przeprowadzono badania strukturalne otrzymanych warstw. Na podstawie oceny właściwości uzyskanych podczas pomiarów twardości, własności mechanicznych (próby zginania i badań zmęczeniowych) oraz badań odporności na zużycie ścierne, wybrano warunki najlepszej technologii. Zastosowane w badaniach azotowanie – podobnie jak poprzednio – spowodowało pogorszenie jakości warstwy stopowanej.

EN

This article is the third in a series of studies concerning laser treatment technologies applied to steel with different chemical compositions. The effects of laser treatment of carbon steels [1] and constructional alloy steels [2] are discussed in the first two articles. In the first one, it is demonstrated that increasing carbon content results in clear growth of the hardness of laser-hardened steel, affects the shape of the layer and the character of discontinuities forming in the melted zone. In the second, the significance of carbon share was confirmed and the influence of alloying elements on temperability of steel was evaluated. Moreover, it was demonstrated that laser treatment destroys the diffusive, nitrided layer. The test results found here are the fruit of collaboration between three research centers: Fraunhofer Institute for Production Technology IPT – Aachen, Insti-tute of Industrial Machinery and Transportation of Poznań University of Technology and the Metal Forming Institute in Poznań. This article contains results of laser treat-ment tests performed on NC11LV steel in its initial (annealed) state and hardened at different temperatures, including in layers situated at varying distances from one an-other. Furthermore, the article provides an evaluation of the quality of alloying by means of powders with varying contents of alloying ingredients of the steel intended for forging tools. The initial structure of NC11LV steel was martensitic with a small amount of residual austenite after hardening at 1020oC, and containing austenite with a small amount of carbides after hardening at 1150oC. It was determined that the hardness of steel in the melted zone (approx. 500 HV0.1) is similar to the hardness of NC11LV steel hardened at 1150oC, and in the transitional zone, the dispersion of hardness measure-ment results is irregular; more so in the initial hardening zone at 1020 oC. The influence of laser beam travel speed on the state of the specimen’s near-surface layer is similar as in articles [1–2]; increasing travel speed reduces the layer’s “parameters”. Tests show that, regardless of the initial state (hardening temperature), laser treatment does not result in beneficial changes of the surface layer of NC11LV steel. However, positive re-sults were obtained in tests of alloying technology for forging tools made of WCL steel. In specimens alloyed using Mo/VC powder, tempering temperature of the alloyed layers was determined (600oC), higher than the tempering temperature of high-speed tool steels. Fifteen variants were evaluated in tests on the selection of technology, in which three groups of powders with different chemical compositions were applied: WC/Co, WC/Co/Cr and Mo/VC, in the appropriate proportion of ingredients and doses. Struc-tural tests of the layers obtained were carried out. Based on evaluation of properties obtained during hardness measurements, tests of mechanical properties (bending and fatigue tests) as well as abrasion resistance tests, the conditions of the best technology were selected. Nitriding applied in the tests caused the quality of the nitrided layer to deteriorate - similarly as before.

4

Mechanical behavior of wheel steels with solid solution and precipitation hardening

Kulyk V. V., Shipitsyn S. Ya., Ostash O. P., Duriagina Z. A., Vira V. V.

Archives of Materials Science and Engineering

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2019

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Vol. 95, nr 2

49--54

EN

Purpose: The aim of the proposed research is to investigate operational properties of a wheel steel treated with simultaneous solid solution and precipitation hardening at various carbon content, in comparison with the standard wheel grade T steel. Design/methodology/approach: The mechanical behaviour of wheel steels with increased content of silicon, manganese, vanadium, and nitrogen at various carbon content has been investigated and compared to that of the standard high-strength wheel grade T steel. The steels were undergo thermal treatment due to austenitic heating up to a temperature of 950.C with cooling down in water to 550.C followed by intense blowing of blanks in the air. After that, a tempering was performed at a temperature in the range of 450-650.C. Static strength (UTS), relative elongation (TEL), impact toughness tests (KCV) were determined on standard specimens. The characteristics of Mode I fatigue crack growth resistance of steel were determined on the basis of fatigue macrocrack growth rate diagrams da/dN–ΔKI, obtained by the standard method on compact specimens with the thickness of 10 mm at a frequency of 10-15 Hz and the stress ratio R = 0.1 and R = 0.5 of the loading cycle. The characteristics of Mode II fatigue crack growth resistance were determined on the basis of da/dN–ΔKII diagrams, obtained earlier method on edge notched specimens with the thickness 3.2 mm at a frequency of 10-15 Hz and R = -1 taking account of the crack face friction. Rolling contact fatigue testing was carried out on the model specimens. Findings: The regularities of the change of mechanical characteristics of the high-strength wheel steel with simultaneous solid solution and precipitation hardening at lowered carbon content under static, impact and cyclic loading are studied. Research limitations/implications: The results obtained using laboratory samples should be checked during a real railway wheels investigation. Practical implications: The investigated steel with simultaneous solid solution and precipitation hardening provides high wear resistance of the tread surface and damage resistance determined on the model wheels. Originality/value: A steel with solid solution hardening due to increased content of silicon (up to 0.7%) and manganese (up to 0.8%) and also with precipitation hardening (at optimal content of vanadium and nitrogen [V‧N]‧104 = 28.9%) at lowered carbon content (0.52) possesses high strength and fatigue fracture toughness in cases of Mode I and Mode II loading, causing better combination of wear and damage resistances of the tread surface of the model wheels, as compared to corresponding parameters for grade T steel.

5

Surface Treatment Proposals for the Automotive Industry by the Example of 316L Steel

Dudek A, Lisiecka B.

Multidisciplinary Aspects of Production Engineering

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2018

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Vol. 1, Iss. 1

369--376

EN

Nowadays, stainless steels are very interesting and promising materials with unique properties. They are characterized high mechanical strengths, high toughness and good corrosion resistance, so that can be used in many industrial sectors. An interesting alternative to steels obtained using the conventional methods is sintered stainless steel manufactured using the powder metallurgy technology. AISI 316L stainless steel is one of the best-known and widely used austenitic stainless steel. Modification of surface properties of stainless steels, in particular by applying the Cr3C2 coating is becoming more and more popular. The technique of atmospheric plasma spraying (APS) was used to deposit Cr3C2 - NiAl powder on stainless steel surface. In this study presents arc surface remelting of two types of stainless steel was used by GTAW method in order to improve function and usability these materials. The results of optical microscope metallographic, hardness and scratch test are presented. The main assumption for this study was to analyze the microstructure and hardness after remelting and alloying the surface of 316L steel (using GTAW method) with current intensity 50 A.

6

The Investigation of Properties of High-Speed Steel After Laser Surface Treatment

Bonek M.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

227--233

EN

The aim of this research paper is to present laser surface treatment technologies, investigation of properties of the HS6-5-3-8 high-speed steel \ alloying with ceramic particles using High Power Diode Laser. Selection of laser operating conditions is discussed, as well as beam face quality after remelting, hardness, micro hardness test, wear resistant. Remelting of the steel with introducing into liquid molten pool the alloying additions in the form of ceramic powders, causes significant increase of properties of surface layer of investigated steel in comparison to its analogical properties obtained through conventional heat treatment, depending on the laser beam power implemented for remelting. The increase of hardness of surface layer obtained throughout remelting and alloying with carbides by high power diode laser is accompanied by increase of tribological properties, when comparing to the steel processed with conventional heat treatment.

7

Effect of additional alloying and heat treatment on phase composition and morphology in Al-Mg-Si-type casting alloy

Boyko V., Czekaj E., Warmuzek M., Mykhalenkov K.

Metallurgy and Foundry Engineering

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2017

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Vol. 43, no. 3

219--239

EN

The structure of permanent mold and high pressure die castings of the AlMg5Si2Mn alloy after alloying with Li and Sc has been investigated by scanning and transmission electron microscopy, hardness and microhardness measurements, energy dispersive X-ray analysis. Three conditions, as cast, solution treated and aged, were investigated. It was shown that in as-cast state, the structure of an alloy having the nominal composition AlMg5Si2Mn consists of four phases: first – the Al based solid solution, second – the (Al) + (Mg2Si) eutectic, third – the primary Mg2Si crystals and fourth – the α-Al(Mn, Fe)Si phase. Similar phases were observed in the alloys containing Sc or Li. After two days of storing in an as-cast condition, the solid solution in all tested alloys decomposes and forms zebra-crossing shaped precipitates. TEM examinations revealed that these precipitates nucleate heterogeneously on dislocations. The solution treatment at 575.0°C results in spheroidization of the Mg2Si lamellas, dissolution of the precipitates and formation of α-Al(Mn, Fe)Si dispersoids, nucleating on the surfaces of Mg2Si lamellas. In the Sc containing alloys, the formation of Al3Sc was detected after 120 min soaking. Further heating resulted in the growth of these precipitates. Aging of the Al-Mg-Si alloys leads to an increase of hardness in all studied alloys. This effect is mainly related to precipitation strengthening, via solid solution decomposition and formation of β’’-phase. In Li-alloyed specimens, plates of β Mg2Si phase were observed together with small cubic-shaped δ’ Al3Li precipitates.

PL

Strukturę odlewów wykonywanych w formach stałych i odlewów wysokociśnieniowych ze stopu AlMg5Si2Mn po stopowaniu Li i Sc badano za pomocą skaningowej i transmisyjnej mikroskopii elektronowej, a także wykonując pomiary twardości i mikrotwardości oraz prowadząc analizę rentgenowską z dyspersją energii. Badano trzy warianty: stan po odlaniu, odlew przesycony i starzony. Wykazano, że w stanie po odlaniu struktura stopu o nominalnym składzie AlMg5Si2Mn składa się z czterech faz: pierwsza – roztwór stały na bazie Al, druga – (Al) + (Mg2Si) eutektyczna, trzecia – pierwotne kryształy Mg2Si i czwarta – α-Al(Mn, Fe)Si. Podobne fazy zaobserwowano w stopach zawierających Sc lub Li. Po dwóch dniach przechowywania w stanie po odlaniu roztwór stały we wszystkich testowanych stopach rozkłada się i tworzy wydzielenia w kształcie przejściowym. Badania TEM ujawniły, że wytrącają one heterogenicznie jądro podczas dyslokacji. Obróbka roztworu przy 575,0°C powoduje sferoidyzację płytek Mg2Si, rozkład wydzieleń i tworzenie dyspersoidów oraz zarodkowanie na powierzchniach płytek Mg2Si. W stopie zawierającym Sc fazę Al3Sc wykryto po 120 min wygrzewania. Dalsze ogrzewanie spowodowało wzrost tych wydzieleń. Starzenie stopów Al-Mg-Si prowadzi do wzrostu twardości wszystkich badanych stopów. Efekt ten jest głównie związany z utwardzaniem wydzieleniowym na skutek rozkładu w stanie stałym i tworzenia fazy β’’. W próbkach ze stopu z litem obserwowano płytki fazy β-Mg2Si wraz z małymi sześciennymi wydzieleniami δ’-Al3Li.

8

Application of the Finite Elements Method for computer simulation of properties of surface layers

Śliwa A.

Archives of Materials Science and Engineering

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2017

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Vol. 86, nr 2

56--85

EN

Purpose: The work presents the application of the Finite Elements Method in a computer simulation whose aim is to determine the properties of PVD and CVD coatings on various substrates and to optimise parameters of a laser surface treatment process of surface layers of tool steels. Design/methodology/approach: The article discusses the application of the finite elements method for simulating the determination of stresses and microhardness of Ti+TiN, Ti+Ti(CN) and Ti+TiC coatings obtained in a magnetron PVD process on a substrate of sinter high-speed steel, of Ti/Ti(C,N)/CrN, Ti/Ti(C, N)/(Ti, Al)N, Ti/(Ti, Si)N/(Ti, Si)N, Cr/ CrN/CrN, Cr/CrN/TiN and Ti/DLC/DLC coatings obtained in a PVD and CVD process on magnesium alloys, of graded and monolayer coatings (Ti, Al)N, Ti(C,N) produced with the PVD arc technique on a substrate of sintered carbides, cermets and oxide tool ceramics and tool steel remelted and alloyed with a high-performance diode laser (HPDL). Modeling of stresses was performed with the help of finite element method in ANSYS and MARC environment, and the experimental values of stresses were determined based on the sin2Ψ. Findings: The models presented satisfy the assumed criteria, and they can be applied for the determination of properties of surface layers and optimisation of PVD and CVD processes and laser alloying and remelting. The results of a computer simulation correlate with experimental results. The models developed allow to largely eliminate costly, timeconsuming and specialist experiments which have to be done during investigations for the benefit of computer simulations. Research limitations/implications: To be able to assess the possibility of application of surface layers, a computer simulation of other properties of coatings has to be additionally carried out, and a strength analysis has to be made of other coatings coated onto various substrate materials. Originality/value: value Computer simulation and modelling is an interdisciplinary field necessary for the development of science and technology, enabling to perform direct visualisation of properties, which cannot be identified in experimental observations. The purpose of computer simulation and modelling is to improve the ability to predict results and to optimise solutions.

9

Optimization of Micro-Alloying Elements for Mechanical Properties in Normalized Cast Steel Using Taguchi Technique

Chokkalingam B., Raja V., Anburaj J., Immanual R., Dhineshkumar M.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 2

171--177

EN

In this study, Taguchi method is used to find out the effect of micro alloying elements like vanadium, niobium and titanium on the hardness and tensile strength of the normalized cast steel. Based on this method, plan of experiments were made by using orthogonal arrays to acquire the data on hardness and tensile strength. The signal to noise ratio and analysis of variance (ANOVA) are used to investigate the effect of these micro alloying elements on these two mechanical properties of the micro alloyed normalized cast steel. The results indicated that in the micro alloyed normalized cast steel both these properties increases when compared to non-micro-alloyed normalized cast steel. The effect of niobium addition was found to be significantly higher to obtain higher hardness and tensile strength when compared to other micro alloying elements. The maximum hardness of 200HV and the maximum tensile strength of 780 N/mm2 were obtained in 0.05%Nb addition micro alloyed normalized cast steel. Micro-alloyed with niobium normalized cast steel have the finest and uniform microstructure and fine pearlite colonies distributed uniformly in the ferrite. The optimum condition to obtain higher hardness and tensile strength were determined. The results were verified with experiments.

10

Analiza oddziaływań mechanicznych elektrod drutowych w procesie mikrostopowania z wykorzystaniem wyładowań elektrycznych

Spadło S., Młynarczyk P.

Mechanik

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2015

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R. 88 nr 4CD

168--171

PL

W artykule przedstawiono analityczne rozwiązanie zagadnienia sił, z jakimi oddziałują pojedyncze włókna szczotki obrotowej z powierzchnią podczas obróbki BEDMA. Przeprowadzono analizę deformacji pojedynczych drucików szczotki, uwzględniając występujące więzy kinematyczne dla przypadku powierzchni płaskiej niepodatnej, z występowaniem tarcia. Przedstawiono wyniki symulacji w postaci zależności sił oddziaływań drucików z powierzchnią w funkcji kąta obrotu szczotki.

EN

In this paper, an analytical procedure is developed in order to evaluate the filament loading of a circular brush. Filament deformation is computed based on the mechanic analysis in conjunction with kinematic constraints for a rigid flat surface with friction taken into account. Numerical results which reveal the relationship between rotation angle and force distribution are reported.

11

Laser surface treatment of cast Al-Si-Cu alloys

Labisz K.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 2

63--86

EN

Purpose: The test results presented in this chapter concern formation of the quasi-composite MMCs structure on the surface of elements from aluminium cast alloys AC-AlSi9Cu and AC-AlSi9Cu4 by fusion of the carbide or ceramic particles WC, SiC, ZrO2 and Al2O3 in the surface of alloys. In addition, within the scope of the tests the phase transformations and precipitation processes present during laser remelting and fusion at appropriately selected parameters: laser power, the rate of fusion and quantity of the ceramic powder fed have been partially examined. Design/methodology/approach: In general, the laser surface processing should result in achievement of the surface layer with the most favourable physical and mechanical properties, in particular enhancement of surface hardness, improvement of abrasion resistance and resistance to corrosion is assumed in relation to the selected aluminium alloys after standard thermal processing. Findings: The presented results of the surface layer include analysis of the mechanisms responsible for formation of the layer, and particularly concern remelting of the substrate and its crystallisation at various parameters of the High Power Diode Laser (HPDL) and the technological conditions of the surface processing, remelting and fusion of the particles in the surface of cast alloys ACAlSi9Cu and ACAlSi9Cu4. For the purpose of testing the structure of the obtained surface layers the test methods making use of the light microscopy method supported with computer image analysis, transmission and scanning electron microscopy, X-ray analysis, X-ray microanalysis, as well as methods for testing the mechanical and usable properties have been used. Practical implications: What is more, development of the technology of surface refinement of cast alloys Al-Si-Cu with the laser fusion methods will allow for complex solving of the problem related to enhancement of the surface layer properties, taking into account both economic and ecological aspects. Originality/value: On the basis of the test result analysis it has been pointed out that in case of the analysed aluminium cast alloys the applied laser surface processing, and the thermal processing preceding it, ensuring occurrence of the mechanisms responsible for material strengthening, enable enhancement of the mechanical and usable properties of the examined alloys. An essential objective is also to indicate the multiple possibilities for continuation of the tests, regarding the light metal alloys aluminium, magnesium and titanium, broadening the current knowledge within the scope of elements and light structures.

12

Surface layer of austenitic stainless steel formed by alloying with REE using high intense pulsed plasma beams (HIPPB)

Sartowska B., Barlak M., Waliś L., Starosta W., Senatorski J.

Inżynieria Materiałowa

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2013

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Vol. 34, nr 6

837--840

EN

The aim of this work was to investigate the changes of stainless steel surface properties (morphology, REE concentration, presence of identified phases) and functional properties (wear and high temperature oxidation resistance) after REE addition with remelting of the surface layer. Modification of the near surface layer of AISI 316L steel was based on the incorporation of rare earth elements (REE) using high intensity pulsed plasma beams (HIPPB) as DPE – Deposition by Pulsed Erosion. DPE is unique technique because melting and doping of the near surface layer occurs in a single step. Samples of AISI 316L steel were irradiated with short (μs scale), intense (energy density 3 J/cm2) pulses. The pulse energy density was sufficient to melt the near surface layer of steel. Heating and cooling processes were of non-equilibrium type. The plasma pulses contain both ions/atoms of (Ce + La) from electrodes material and the working gas – nitrogen. Scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS) and X-ray diffraction analysis were used for initial and modified surface characterization. The wear tests and high temperature oxidation processes were carried out. An improvement of tribological properties and increasing of high temperature oxidation resistance of modified surface layer was observed as compared with initial material.

PL

Celem pracy było zbadanie zmian właściwości powierzchniowych (morfologia powierzchni, koncentracja REE, obecność zidentyfikowanych faz) i właściwości użytkowych (odporność na zużycie przez tarcie i wysokotemperaturowe utlenianie) po domieszkowaniu REE z jednoczesnym przetopieniem warstwy wierzchniej stali austenitycznej. Modyfikacja warstwy wierzchniej stali AISI 316L polegała na wprowadzeniu do jej warstwy powierzchniowej pierwiastków ziem rzadkich (REE) za pomocą intensywnych impulsów plazmowych (HIPPB) metodą DPE – Depozycja przez Impulsową Erozję (Deposition by Pulse Erosion). Metoda DPE jest unikatową techniką, ponieważ stopienie i domieszkowanie warstwy wierzchniej materiału przebiega jednocześnie. Próbki stali AISI 316L zostały naświetlone krótkimi (skala μs), intensywnymi (gęstość energii 3,0 J/cm2) impulsami. Gęstość energii pojedynczego impulsu była wystarczająca do stopienia warstwy wierzchniej stali. Procesy grzania i chłodzenia miały charakter nierównowagowy. Plasma zawierała jony/atomy pochodzące z materiału elektrod (Ce + La) i azotu jako użytego gazu roboczego. Materiały wyjściowy i modyfikowane scharakteryzowano za pomocą: skaningowej mikroskopii elektronowej (SEM), mikroanalizy rentgenowskiej (EDS) i dyfrakcji promieniowania rentgenowskiego (XRD). Zostały przeprowadzone badania odporności na zużycie przez tarcie oraz odporności na wysokotemperaturowe utlenianie. Uzyskano poprawę właściwości tribologicznych oraz zwiększenie odporności na wysokotemperaturowe utlenianie warstw modyfikowanych w porównaniu z materiałem niemodyfikowanym.

13

Effect of Chemical Composition on the Scraper Conveyor Parts Hardness and Wear Resistance

Glushkova D.

Challenges of Modern Technology

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2013

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Vol. 4, no. 4

18--20

EN

In this paper Tthe optimal chemical composition of steel that provides high hardness and wear resistance of scraper conveyor parts is offeredhas been presented.

14

The effect of shielding gas composition on microstructure and abrasive wear resistance fabricated with PTA alloying technique

Çay V. V., Ozan S., Gök M. S., Erdoğan A.

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 4

1137--1145

EN

In this study, SAE 1020 steel surfaces were separately alloyed with preplaced high-carbon-ferro-chromium (FeCr), ferro-molybdenum (FeMo) and ferro-titanium (FeTi) powders by using plasma transferred arc (PTA) heat source. By using three different types of shielding gas compositions during the alloying process, the study investigated the effects of modified shielding gas composition on the microstructure, hardness, and abrasive wear resistance of specimens. The most homogenous microstructure and the highest wear resistance was obtained in the gaseous environment which included 3% of H2. Increasing this rate to 5 % in the shielding gaseous composition caused gaps and pores in the microstructure and caused a decrease in the wear resistance. The x-ray examinations of the specimens identified ferro-molybdenum and ferro-titanium solid solutions, ferrit, austenite and martensite phases in their microstructure as the first phase and FeC, Cr7C3, Cr3C2, Fe3C, Fe7C3, MoC and TiC phases as the second phase. As a result, it was concluded that changes in shielding gas composition in surface alloying process affected specimens’ microstructure and abrasive wear properties.

PL

Powierzchnie stalowe SAE 1020 były oddzielnie stopowane z wcześniej nałożonymi proszkami wysokowęglowego żelazo-chromu (FeCr), żelazo-molibdenu (FeMo) i żelazo-tytanu (FeTi) za pomocą techniki PTA. Dzięki zastosowaniu trzech różnych typów gazu osłonowego w trakcie procesu wytwarzania stopu, badano wpływ modyfikacji składu gazu osłonowego na mikro- strukturę, twardość i odporność na ścieranie próbek. Najbardziej jednorodną mikrostrukturę i najwyższą odporność na ścieranie otrzymuje się w środowisku gazowym, które zawiera 3% H2. Zwiększenie zawartości H2 do 5% w składzie gazu osłonowego spowodowało powstanie luk i porów w mikrostrukturze oraz spadek odporności na ścieranie. Badania dyfrakcji rentgenowskiej próbek pozwoliły zidentyfikować roztwory stałe żelazo-molibdenu i żelazo-tytanu, ferryt, austenit i martenzyt jako pierwszą fazę w ich mikrostrukturze, oraz FeC, Cr7C3, Cr3C2, Fe3C, Fe7C3, MoC i TiC jako drugą fazę. W związku z tym stwierdzono, że zmiany w składu gazu osłonowego w procesie stopowania wpłynęły na mikrostrukturę próbek i właściwości ścierne.

15

Influence of the HPDL surface treatment of the X40CrMoV5-1 and 32CrMoV12-28 tool steels on wear resistance

Jonda E., Labisz K., Pakieła W.

Archives of Materials Science and Engineering

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2013

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Vol. 64, nr 2

152--159

EN

Purpose: This paper presents the results of laser remelting influence on structure and properties of the surface of the X40CrMoV5-1 and 32CrMoV12-28 hot work tool steels, carried out using the high power diode laser (HPDL). Structure changes were determined in the work, especially structure fragmentation. Also hardness investigation of the different remelting areas was performed. The purpose of this work was also to determine technological and technical parameters for a right performed HPDL remelting process. Boron nitride powder was used for alloying. The goal of this work was also to determine technical and technological conditions for remelting the surface layer with HPDL. Design/methodology/approach: Here are discusses the new methodology ways which can be applied in case of improving of the surface layer properties. A new laser treatment techniques applied in metal surface technology is here the most important feature. Also the influence of ceramic powders to the structure in all zones is investigated. Optical and scanning electron microscopy, EDS point wise and area microanalysis was used to characterize the microstructure and to investigate the intermetallic phases occurred. Findings: The most important factor is the zone structure of the surface layer which was coming into existence without cracks and defects as well as has a considerably higher hardness value compared to the non remelted material. It was find out, that the hardness of the alloyed surface layer increases according to the applied laser power. The highest power applied gives the highest hardness value in the remelted layer mostly in all user ceramic powders. Practical implications: The reason of this work was also to determine the laser treatment parameters, particularly the laser power, to achieve a good layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant for work extreme conditions. The most important practical implication investigated in this work improves the appliance of HPDL laser for alloying and remelting of hot work tool steel. Originality/value: The originality of this work is assured through the using of an high-level up-to-date laser device for improvement of steel surface layer mechanical properties.

16

HPDL laser alloying of Al-Si-Cu alloy with Al2O3 powder

Labisz K., Tański T., Dobrzański L.A., Janicki D., Korcina K

Archives of Materials Science and Engineering

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2013

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Vol. 63, nr 1

36--45

EN

Purpose: This article presents results of investigation of laser alloyed cast aluminium alloys after standard heat treatment. In general into the aluminium matrix there are fed different types of ceramic particles including aluminium oxide. The purpose of this work was also to determine the laser treatment conditions for surface hardening of the investigation alloys, like laser power, as well the laser scan rate. Design/methodology/approach: The investigations were performed using light and electron microscopy (SEM) for structure determination, using EDS microanalysis it was also possible to determine the chemical composition changes. The morphology and size of the ceramic powder particles was also possible to determine. Findings: Concerning the laser treatment conditions for surface hardening the scan rate as well as the laser power influence was studied. The structure of the surface laser tray changes in a way, that there are very high roughness of the surface zone and the flatness or geometry changes. Research limitations/implications: The aluminium samples were examined metallographically using optical microscope with different image techniques as well as scanning electron microscope. Practical implications: Developing of new technology with appliance of Al alloys, High Power Diode Laser and diverse ceramic powders can be possible to obtain, based in findings from this research project. Some other investigation should be performed in the future, but the knowledge found in this research concerning the proper process parameters for each type of alloy shows an interesting investigation direction. Originality/value: The combination of metallographic investigation, including electron microscope investigation and High Power Diode Laser (HPDL) treatment parameters makes the investigation very attractive especially for automobile industry, and transportation where parts manufactured of aluminium alloys are a very important because of its surface properties.

17

Investigation of the surface quality alloying with the electrodes of chromium-nickel steel

Spadło S., Młynarczyk P.

Structure and Environment

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2012

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Vol. 4, no. 2

52--59

EN

The paper presents a brief study of electro-discharge mechanical machining with an elastic, discrete electrode. The factors causing the chemical composition and surface roughness of superficial layer have also been taken into consideration. Attention has also been given to the relation between the material of electrode and the superficial layer composition. The superficial layer obtained by BEDMM consist of several layers. At the top, a molten and resolidified laver, called recast layer, is observed. This layer is usually present because material removal in BEDMM is mainly based on melting process of the workpiece material. In the recast layer in machining condition the mixing and diffusion of the material hot electrode and the workpart can occur.

18

Laser modification of the materials surface layer - a review paper

Kusiński J., Kac S., Kopia A., Radziszewska A., Rozmus-Górnikowska M., Major B., Major L., Marczak J., Lisiecki A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2012

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Vol. 60, nr 4

711-728

EN

The state of laser processing in surface materials modification in Poland is reported, based on own experience, coworkers and coauthors results, as well the literature review. The curriculum concerning historical development of lasers and laser technology in Poland, laser-matter interaction, as well basis of different laser techniques applied in materials surface engineering (solid state hardening, melting, alloying, cladding, ablation, shot peening, cleaning and texturing) are reviewed, and compared with results of coauthors, as well with a wide range of Polish authors papers. Finally, it is concluded that overall state of research on laser application in surface engineering in Poland is well developed and still growing industrial application is observed.

19

HPDL laser alloying of heat treated Al-Si-Cu alloy

Labisz K., Tański T., Dobrzański L.

Archives of Materials Science and Engineering

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2012

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Vol. 54, nr 1

13-21

EN

Purpose: There are presented in this paper the investigation results of microstructure of the cast aluminium alloys in the as cast state as well after laser treatment used for alloying with carbide and oxide ceramic powders like aluminium oxide and silicon carbide, titanium carbide, vanadium carbide and tungsten carbide. The purpose of this work was also to determine the laser treatment conditions for surface hardening of the investigation alloys, like laser power, as well the laser scan rate. Design/methodology/approach: The investigations were performed using light and electron microscopy for the microstructure determination. By mind of the transmission electron microscopy, especially selected area diffraction method appliance it was possible to determine the phases occurred in the alloy in the as cast state. The morphology and size of the Mg2Si was also possible to determine as well the lattice parameters for this phase. Findings: Concerning the laser treatment conditions for surface hardening the scan rat as well as the laser power influence was studied. It was used a power in the range between 1.0 and 2.0 kW The structure of the surface laser tray changes in a way, that there are very high roughness of the surface zone and the flatness or geometry changes in an important manner, crucial for further investigation. Research limitations/implications: The aluminium samples were examined metallographically using optical microscope with different image techniques as well as transmission electron microscope. Practical implications: Developing of new technology with appliance of Al alloys, High Power Diode Laser and diverse ceramic powders can be possible to obtain, based in findings from this research project. Some other investigation should be performed in the future, but the knowledge found in this research concerning the proper process parameters for each type of alloy shows an interesting investigation direction. Originality/value: The combination of metallographic investigation for cast aluminium alloys – including electron microscope investigation – and HPDL treatment parameters makes the investigation very attractive for automobile, aviation industry, and others where aluminium alloys plays an important role.

20

Microstructure and microhardness of Ti6Al4V alloy treated by GTAW SiC alloying

Bochnowski W.

Archives of Foundry Engineering

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2012

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Vol. 12, iss. 2

261-266

EN

In this work, the change of the structure and microhardness of Ti6Al4V titanium alloy after remelting and remelting with SiC alloing by electric arc welding (GTAW method) was studied. The current intensity equal 100 A and fixed scan speed rate equal 0,2 m/min has been used to remelting surface of the alloy. Change of structure were investigated by optical and scanning electron microscopy. Microhardness test showed, that the remelting of the surface does not change the hardness of the alloy. Treated by GTAW SiC alloying leads to the formation of hard (570 HV0,1) surface layer with a thickness of 2 mm. The resulting surface layer is characterized by diverse morphology alloyed zone. The fracture of alloy after conventional heat treatment, similarly to fracture after remelting with GTAW is characterized by extremely fine dimples of plastic deformation. In the alloyed specimens the intergranular and crystalline fracture was identified.