Wyniki wyszukiwania - BazTech

1

Studying the Effectiveness of Shaped Charge Jets Created by Graphene-containing Shaped Charge Liners

Majewski Tomasz, Trzciński Waldemar A., Szymańczyk Leszek

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2024

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Vol. 15, Nr 1 (55)

39--54

EN

The paper presents selected results of studies conducted within the framework of the following research project: “Use of graphene and new multilayer explosive technologies in materials for shaped charge liners" (The National Centre for Research and Development in Poland: project No: DOB-BI08/03/01/2016). This study was performed by a consortium made up of the following entities: Institute of Precision Mechanics, Military University of Technology and the Mototechnika company (Poland). The main objective of the performed experiments was to test the effectiveness of shaped charge liners produced with the use of powder metallurgy methods, from mixtures containing copper powder and graphene-coated copper powder. The content of the latter equaled 0%, 1%, 5% and 10%, respectively. Shaped charge jets created with the use of liners made from the powder mixtures tested were recorded with the help of X-ray technology. Firing tests were conducted against steel barriers and the depth of penetration was determined. The obtained results showed that the addition of graphene powder to pure copper powder practically does not increase the depth of penetration of the shaped charge jet compared to scenarios in which sintered liners without this additive were used.

PL

W artykule zostały przedstawione wybrane wyniki badań przeprowadzonych w ramach realizacji projektu badawczego: „Zastosowanie grafenu i nowych technologii wielowarstwowych materiałów wybuchowych w materiałach na wkładki kumulacyjne” (nr projektu NCBiR: DOB-BI08/03/01/2016). Praca ta była przeprowadzona w konsorcjum, w skład którego wchodziły: Instytut Mechaniki Precyzyjnej, Wojskowa Akademia Techniczna oraz przedsiębiorstwo Mototechnika. Głównym celem wykonanych eksperymentów było zbadanie skuteczności wkładek kumulacyjnych, wytworzonych metodami metalurgii proszków, z mieszanek zawierających proszek miedzi oraz proszek miedzi pokryty grafenem. Zawartość tego ostatniego wynosiła odpowiednio:0%, 1%, 5% i 10%. Dokonano rentgenograficznej rejestracji strumieni kumulacyjnych przy zastosowaniu ładunków zawierających wkładki wytworzone z testowanych mieszanek proszkowych. Przeprowadzono próby strzelania do przegród stalowych i określono głębokość penetracji. Otrzymane wyniki badań wykazały, że dodatek proszku grafenowanego do proszku czystej miedzi praktycznie nie zwiększa głębokości wnikania strumienia kumulacyjnego w stosunku do przypadku, gdy zastosowano wkładki spiekane bez tego dodatku.

2

Overview of the plant-based synthesis of metal and metal oxide nanoparticles and their potential application in the formation of protective coatings

Duda Alicja, Kopyciński Bartosz

Ochrona przed Korozją

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2023

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nr 7

197--205

EN

Technologies for the production of nanomaterials have been developed for many years. Despite the remarkable achievements in this field, nanotechnologies contribute to serious environmental pollution. One of the interesting directions in the search for new, green solutions limiting their harmful impact on nature is the use of plant extracts as substrates in the techniques of synthesis of metal nanoparticles and metal oxides. This article briefly reviews the current state of knowledge on the preparation of metallic nanoparticles via green chemistry synthesis methods. The general mechanism of these processes is presented in an accessible way. In addition, current trends in the field of their use in the formulation of paints and varnishes with antifouling properties and as components of protective coatings preventing corrosion are discussed. A noteworthy way of using metallic nanoparticles in agriculture as a factor inhibiting the negative effects of salinity on the growth of crops was also mentioned. Despite the constantly growing number of scientific reports on these issues, this topic still requires a comprehensive discussion along with a detailed analysis of the synthesis processes. A comprehensive approach will certainly contribute to a better knowledge and understanding of this subject and the improvement of the quality of works devoted to the green synthesis of metallic nanoparticles.

PL

Technologie wytwarzania nanomateriałów są rozwijane od wielu lat. Pomimo niezwykłych osiągnięć w tej dziedzinie nanotechnologie przyczyniają się do poważnego zanieczyszczenia środowiska. Jednym z interesujących kierunków poszukiwania nowych, zielonych rozwiązań ograniczających ich szkodliwy wpływ na przyrodę jest wykorzystanie ekstraktów roślinnych jako substratów w technikach syntezy nanocząstek metali i tlenków metali. W artykule dokonano krótkiego przeglądu obecnego stanu wiedzy na temat otrzymywania nanocząstek metalicznych z użyciem metod syntezy biologicznej. W przystępny sposób przedstawiono ogólny mechanizm przebiegu tych procesów. Omówiono ponadto aktualne trendy w zakresie ich wykorzystywania w recepturowaniu farb i lakierów o właściwościach przeciwporostowych oraz jako składników powłok ochronnych zapobiegających korozji. Zwrócono również uwagę na kwestię zastosowania nanocząstek metalicznych w charakterze związków hamujących negatywny wpływ zasolenia na wzrost roślin uprawnych. Pomimo stale rosnącej liczby doniesień naukowych dotyczących tych zagadnień wciąż wymagają one kompleksowego omówienia wraz ze szczegółową analizą przebiegu procesów syntezy. Całościowe ujęcie z pewnością przyczyni się do lepszego poznania i zrozumienia tej tematyki oraz publikowania prac o wysokiej jakości.

3

Effect of Particle Size of a Powder upon the Properties and Microstructure of Boron-modified Fe-Ni-Mo-Cu Sinters

Karwan-Baczewska Joanna, Perek-Nowak Małgorzata, Majchrowska Magdalena, Rosso Mario

Journal of Casting & Materials Engineering

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2023

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Vol. 7, no. 1

1--8

EN

The article discusses the effect of different particle fractions of prealloyed iron powder on the microstructure, density and hardness of sintered material. Each particle fraction (apart from 160–200 µm, which is a trace fraction) was modified with boron, its contents being, respectively, 0.2 wt.%, 0.4 wt.% and 0.6 wt.%. Next, the powder mixtures were pressed under a pressure of 600 MPa, and the final compacts were subject to sintering at 1200°C for 60 min in a hydrogen atmosphere. It was observed that the higher values of density and hardness were found in samples made from finer fractions of powder. A higher homogeneity of the microstructure and the highest degree of compactness was obtained in sinters from powder of 40–56 µm particle size, with 0.4 wt.% boron. Due to the use of small particle fractions of prealloyed powder, a higher degree of compactness in sinters was obtained with lower boron content. Also indicated was which particle fraction of Fe-Ni-Mo-Cu powder should be applied to obtain density in sinters with boron addition equal to almost 100% of the relative density of the analyzed alloy. The presented studies have both scientific and technological aspects.

4

Comparison of ultrasonic and other atomization methods in metal powder production

Bałasz B., Bielecki M., Gulbiński W., Słoboda Ł.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 116, nr 1

11--24

EN

Purpose The results showed that the UA powder has a finer average particle size with a narrower statistical distribution of particles than those made by the GA method. Because the UA powder has a higher sphericity and lower porosity, Generally, UA offers better-quality powders in terms of properties such as higher tap density, better flowability and low oxygen content. Design/methodology/approach Ultrasonic atomization (UA) with melting raw material by an electric arc. Characterisation of the powders: particle size distribution (PSD), density, and flowability were carried out. Other parameters, such as microstructure, deviation in the chemical composition and powder surface morphology, were also investigated. Findings The results showed that the UA powder has a finer average particle size with a narrower statistical distribution of particles than those made by the GA method. Because the UA powder has a higher sphericity and lower porosity, Generally, UA offers better-quality powders in terms of properties such as higher tap density, better flowability and low oxygen content. Research limitations/implications As an example of semi-industrial scale application of the UA system, the Ti6Al4V and TiAl powders were produced after remelting the wire. The UA system is commercially available for processing any metallic material. Practical implications The test campaign results showed that the Ti6Al4V powder produced by the ultrasonic atomisation has a similar or better quality as those available from large-scale gas atomisation plants. Originality/value The new method of UA powder production was analysed in terms of key powder parameters. The properties of the titanium-based powder produced this way were analysed with a view to future applications.

5

Wpływ parametrów wytwarzania na mikrostrukturę i właściwości spiekanych kół zębatych wykonanych na bazie proszku Distaloy AQ

Sułowski Maciej, Dąbrowski Robert, Żarów Martyna

Inżynieria Materiałowa

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2023

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Vol. 44, nr 1

6--11

PL

Zbadano wpływu parametrów wytwarzania, tzn. infiltracji miedzią, na mikrostrukturę i właściwości mechaniczne kół zębatych wytworzonych techniką metalurgii proszków na bazie proszku żelaza Distaloy AQ. Zakres badań obejmował określenie zmiany wymiarów kół oraz ich gęstości, przed i po procesie infiltracji, pomiar wytrzymałości na statyczne zginanie zębów, pomiar mikrotwardości kół zębatych oraz analizę ich mikrostruktury. Koła zębate podzielono na cztery grupy; jedna z nich nie była infiltrowana miedzią, pozostałe trzy infiltrowano kolejno jednym (1,4% Cu), dwoma (2,8% Cu) i trzema (4,2% Cu) miedzianymi pierścieniami. Stwierdzono, że infiltracja miedzią powoduje wzrost wytrzymałości na zginanie badanych spieków, lecz tylko w przypadku zawartości 1,4% Cu. Większa ilość miedzi powoduje obniżenie wytrzymałości na zginanie zębów kół. Badania wykazały również, że infiltracja miedzią nie wpływa korzystnie na mikrotwardość kół zębatych.

EN

The influence of production parameters i.e., copper infiltration, on the microstructure and mechanical properties of gear wheels initially manufactured by powder metallurgy was investigated. Distaloy AQ iron powder was used for production these gears. The scope of research included the determination of changes in the dimensions of the gear wheels and their density, before and after the infiltration process, measurement of the strength to static bending, measurement of the microhardness of the gear wheels and analysis of their microstructure. The gear wheels are divided into four groups; one of them was not infiltrated with copper, the remaining three were infiltrated successively with one (1.4% Cu), two (2.8% Cu) and three (4.2% Cu) copper rings. It was found that copper infiltration increases the bending strength of the tested sinters, but only in the case of 1.4% Cu content. The greater amount of copper reduces the bending strength of the gear wheels. Research has also shown that copper infiltration does not have a positive effect on the microhardness of gear wheels.

6

The role of the matrix in SiC reinforced composites

Madej Marcin, Leszczyńska-Madej Beata, Wąsik Anna, Kopeć-Surzyn Anna

Composites Theory and Practice

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2023

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R. 23, nr 1

30--36

EN

This article presents a comparison of the properties of composites based on aluminum or aluminum alloy (Al4Cu) rein- forced with silicon carbide SiCp. The main objective was to analyze the possibility of producing an Al + Cu alloy matrix by basic powder metallurgy methods and its influence on the final properties of the composite. The composites were produced by pressing and sintering, basic powder metallurgy techniques, in order to reduce the manufacturing costs. Sintering was carried out in nitrogen due to the favorable effect of this atmosphere on the sintering of aluminum-based materials. Silicon carbide SiC was used as the reinforcing phase. The study clearly showed that the use of a matrix made of a mixture of Al and Cu powders results in an almost twofold increase in hardness (from 32 to about 60 HB) and a more than twofold increase in flexural strength (from about 200 to more than 450 MPa). Observations of the microstructure confirmed the diffusion of copper into the aluminum and the facets of the Al2Cu phase.

7

Effect of MHA on tribo-behaviour of Al-MHA-Si3N4 hybrid composites

Faris Mohammad, Suhaib Mohd, Ahmed Mumtaz

Composites Theory and Practice

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2023

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R. 23, nr 1

37--43

EN

In the contemporary research community, hybrid composites with improved performance are emerging as a trend, overcoming the drawbacks of conventional composites and satisfying needs in tribological applications. In this work, Al-MHA-Si3N4 hybrid composites reinforced with various weight percentages of mustard husk ash (MHA), 0, 2.5, 5, 7.5% and 10%, produced by powder metallurgy techniques at 300, 400, 500, 600 and 700 MPa compaction pressure were analysed. The microstructural characterization of the metal matrix hybrid composites, followed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) investigations show the homogeneous distribution of the reinforcement in the metal matrix. A sliding wear study without lubrication was performed on a pin-on-disc wear testing machine under the following sliding conditions: sliding velocity (SV) of 1.5 m/s, sliding distance (SD) of 300 m and applied loads of 25 N and 35 N. The deformation of the worn surfaces was also investigated. It was found that the tribological characteristics of the composites were enhanced by increasing the weight percentage of MHA and the compaction pressure.

8

The Application of Fuzzy Logic Analysis for the Fast Calculations of Proper Parameters of Manufacturing Titanium Alloys from Powders

Zyguła Krystian, Wojtaszek Marek

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

703--710

EN

This paper presents a method based on the use of fuzzy logic for the rapid selection of optimal induction sintering parameters. The prepared fuzzy controller uses expert knowledge developed from the results of induction sintering tests of Ti-5Al-5Mo-5V-3Cr alloy green compacts produced from a mixture of elemental powders. The analysis of the influence of the applied sintering parameters on the material characteristics was based on the evaluation of the microstructure state and the measurement of the relative density of the samples after sintering. In this way, a universal tool for estimating the sintering parameters of titanium powder-based green compacts was obtained. It was shown that with the help of fuzzy logic it is possible to analyze the influence of the parameters of the manufacturing process of metal powder materials on the quality of the obtained products.

9

Susceptor-Assisted Rapid Microwave Sintering of Al-Kaolin Composite in a Single-Mode Cavity

Venkatesh V.S.S., Kumar Sunil, Patnaik Lokeswar

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

799--806

EN

The present research addresses the low-temperature sintering of 4% kaolin clay reinforced aluminium composite using susceptor-aided microwave sintering at 2.45 GHz frequency. Kaoline clay the naturally available mineral in the north-eastern regions of india. The study aims to convert this kaoline clay into the value added product with enhanced mechanical properties. The Al-x% Kaolin (x = 2, 4, 6, 8, 10) composite was fabricated through the powder metallurgy process by the application of 600 MPa compaction pressure. The composite corresponding to optimum ultimate tensile strength (U.T.S) was subjected to single-mode cavity microwave-assisted sintering by varying the sintering temperatures as 500°C, 550°C and 600°C. The effect of incorporating kaolin clay on the dielectric characteristics of composite powders, as well as the effect of sintering temperature on the microstructural changes and mechanical characteristics of Al-4%Kaolin composites were also examined. Results concluded that the addition of 4 wt% kaolin powder improves the dielectric characteristics of the composite powder. The maximum Hardness. Compression strength and U.T.S of 97 Hv, 202 MPa and 152 MPa respectively achieved for the Al-4% Kaolin composite sintered at 550°C. The higher fracture toughness of 9.56 Ma. m1/2 reveals the ductile fracture for the composite sintered at 550°C.

10

Wpływ parametrów wytwarzania na mikrostrukturę i właściwości spiekanych kół zębatych o składzie Fe-2,5%Mn-0,8%C

Sułowski Maciej, Dąbrowski Robert, Zawilińska Iga

Inżynieria Materiałowa

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2022

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Vol. 43, nr 6

11--15

PL

W pracy zbadano wpływ parametrów wytwarzania, a w szczególności infiltracji miedzią, na właściwości mechaniczne oraz mikrostrukturę spiekanych kół zębatych. Koła zębate spiekano w temp. 1150°C przez 60 min w atmosferze mieszaniny 70% N2 i 30% H2. Następnie poddano je ponownemu spiekaniu w atmosferze będącej mieszaniną 95% N2 i 5% H2 w czasie 60 min w temp. 1120°C, połączonemu z infiltracją miedzią (1,41–4,20%) metodą nakładkową. Po spiekaniu stale poddawano pomiarom gęstości, badaniom właściwości mechanicznych i badaniom metalograficznym. Wykazano, że infiltracja miedzią prowadzi do wzrostu gęstości oraz twardości badanych kół. Największą wytrzymałość na statyczne zginanie zębów wykazały koła nieinfiltrowane miedzią, a najmniejszą zęby kół infiltrowanych 4,2% Cu.

EN

The aim of this work was to investigate the influence of processing parameters, in particular copper infiltration, mechanical properties and microstructure of sintered Fe-2.5% Mn-0.8% C gear wheels. Gear wheels were sintered at 1150°C for 60 min in mixture of 70% N2 and 30% H2. Following this process, the wheels were re-sintered at 1120°C for 60 min in 95% N2 and 5% H2 atmosphere and combined with copper (1.41–4.20%) overlay infiltration method. After infiltration, density and mechanical properties were measured. The results of investigations show that after copper infiltration density and hardness of gears increased. The highest teeth bend strength was obtained for not infiltrated gears. The lowest bend strength value was recorded for gears infiltrated with 4.2% Cu.

11

Manufacturing and properties of al-al alloy bimetallic composites obtained from powders by hot extrusion

Wojtaszek Marek, Zyguła Krystian

Composites Theory and Practice

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2022

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R. 22, nr 4

211--218

EN

This paper presents the process of manufacturing bimetallic composites in the shell-core system. Al17Si5Fe3Cu1.1Mg0.6Zr alloy powder was used for the shell. Pure aluminum was used as the core of the composite, respectively, in the form of a cast and then rolled rod, and in the form of a semi finished product obtained from aluminum powder. The semi-finished powders were produced by means of the uniaxial hot pressing method. From the components prepared in this way, an extrusion chargé was made by machining in an alloy shell-core system. Permanent bonding of the components and forming the required shape of the composites was carried out using direct hot extrusion under isothermal conditions. It was confirmed that the application of powder metallurgy technology for the production of one or both component materials makes it possible to conduct the extrusion of the components with significantly different plasticity without violating the cohesion of the layers. This approach made it possible to produce layered composites with high-strength properties of the outer layer and with a ductile core. The microstructural state of the components was evaluated, focusing on the continuity of the transition zone between the components. Observations of the separation lines between the layers revealed that the zone between the components was continuous, which was found for both composites, regardless of the examined cross-section. On this basis, it was concluded that the direct hot extrusion process, carried out under the adopted parameters, made it possible to combine the components very well. Selected properties of the layered composites were also determined. It was shown that the proposed method, combining powder metallurgy and hot forming technologies, makes it possible to obtain a continuous connection of components and produce products with properties significantly differentiating in the core and shell zones. These properties can be controlled by appropriate selection of the components, as well as by the method of manufacturing the core. Potential applications of the studied materials include the manufacture of bimetallic components for operation in conditions where significantly different properties of the outer zone and the core are required.

12

HA-ZnO-Fe3O4 composite manufactured by wet powder metallurgy process for implant applications

Gupta Ruchi, Agarwal Mayank, Singh Vinay Pratap

Composites Theory and Practice

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2022

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R. 22, nr 1

40--43

EN

A hydroxyapatite (HA) based biocompatible and bioactive composite is an appropriate choice for bio-implants. This experimental work presents the influence of ZnO and Fe3O4 on the microstructure of HA-ZnO-Fe3O4 composites synthesized by the wet powder metallurgy process. These composites were characterized using SEM, energy-dispersive X-ray spectroscopy (EDS), and XRD. The obtained results showed the effect of the addition of Fe3O4 on the interface formation, which is exhibited by interconnected pores and sintered neck in the micrographs. The observed porosity helps to enhance the required osseointegration for the fixation of implants with human bones.

13

Aluminium oxide (Al22O3)-few layer graphene (FLG) reinforced aluminium hybrid composites

Kaykılarlı Cantekin, Altınışık Zehra, Kılıç E. Can, Uzunsoy Deniz, Yeprem H. Aygül

Composites Theory and Practice

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2022

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R. 22, nr 2

72--78

EN

The present study investigates the microstructural and mechanical properties of few layer graphene (FLG, 0.1 to 5 wt.%) and aluminium oxide (Al22O3, 4 to 20 wt.%) reinforced Al6061 matrix composites prepared via mechanical alloying (MA), uniaxial pressing and pressureless sintering. The effects of the amounts of Al22O3 and FLG were studied. MA was carried out at 300 rpm for 3 h in a planetary ball mill in argon atmosphere. The mechanically alloyed (MAed) powders were compacted via uniaxial pressing (400 MPa) and sintering (620°C, 2 h). The microstructural and mechanical properties of the Al-xAl22O3-yFLG powders and bulk samples were investigated via X-ray diffraction (XRD), light microscopy (LM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), the Archimedes’ method and a hardness test. In the XRD analysis, the aluminium carbide (Al4C3) phase was not detected. The SEM, LM micrographs and EDS results show that the produced composites have a homogeneous structure. Based on the Archimedes’ method, the densification rates of the reinforced samples were higher than the unreinforced sample. The Al22O3-3FLG sample exhibited the highest relative density, 99.25%. According to the hardness measurements, the highest hardness value was 87.28 HV for the Al22O3-1FLG composite and increased twofold compared to Al6061.

14

The Study of Copper Alloy with Graphene Additive via x-Ray Diffraction

Masri Mohamad Najmi, Mohammad M., Yusoff Mahani, Mamat Sarizam, Teo Pao Ter, Othman R., Irfan Abd Rahim, Singh Pramod K.

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

1051--1053

EN

This study evaluated the effect of milling speed and compaction pressure on the densification and morphology of the CuZn-Gr composite. The composite was prepared by using the powder metallurgy technique. The effect on the microstructural and compaction was determined based on different milling speeds. The different milling speeds involved were 175, 200, 225, and 250 rpm. Meanwhile, the different compaction pressures used in this study were 127, 250, 374, and 500 MPa. The properties of the milled powder gave the result to green density and densification parameters. The XRD pattern of Cu and Zn broadened as milling time increased.

15

The influence of Iron and Aluminium Powder Pressing on the Course of Shrinkage and Properties of the Fe40Al Phase Obtained by Reaction Sintering

Berendt-Marchel M., Siemiaszko Dariusz

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

121--126

EN

The effect of the compaction rate on the structure, microstructure and properties of Fe-Al sinters obtained during the SHS reaction is presented in this paper. It was found that increasing the uniaxial pressing pressure led to the increase of the contact area between iron and aluminium particles, which improved the conduction and lowered heat losses during the self-propagating high-temperature synthesis (SHS) reaction and thus result with a sintered material with an improved phase homogeneity. On the other hand, an increase in the pressing pressure causes air be trapped in the pores and later on reacts with iron and aluminium to form oxides. In this work, the shrinkage course was analysed at six different pressing pressures: 50, 100, 150, 200, 300 and 400 MPa. The green compacts were then subjected to the PAIS process (pressure-assisted induction sintering) at a temperature of 1000°C under a load of 100 kN for 5 min. Such prepared samples were subjected to density, porosity, and microhardness (HV0.1) measurements. X-ray diffraction phase analysis and SEM observations were performed together with EDS chemical composition measurements. For studied chemical composition of the samples and sample geometry, 200 MPa compacting pressure was found to be optimal in order to obtain the best sample homogeneity.

16

Sintering Behavior and Mechanical Property of Cu-Sn Alloy with Ag Addition Produced by Pulsed Electric Current Sintering

Lee Se Hwan, Ahn Byungmin

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 4

1475--1479

EN

This work mainly focuses on the sintering behavior of the Cu-Sn alloy with the addition of Ag up to 4 wt% after pulsed electric current sintering (PECS) process for ultra-fast sintering. The microstructural evolution was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and density measurements. The mechanical properties were evaluated via measurements of transverse rupture strength (TRS) and Rockwell hardness. The mechanism during the sintering process has been discussed thoroughly, and the effect on porosity with the addition of the Ag is also correlated. The results showed that the growth of porosity progressed with the amount of Ag up to 2 wt%, and further addition of Ag leads reduction in porosity. The effect on mechanical properties were improved slowly as the amount of Ag increased.

17

Porosity Quantification of Additive Manufactured Ti6Al4V and CoCrW Alloys Produced by L-PBF

Bidulský Robert, Petroušek Patrik, Bidulská Jana, Hudák Radovan, Živčák Jozef, Actis Grande Marco

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

83--89

EN

The main aim of the present paper is to evaluate the porosity and mechanical properties of Ti6Al4V and CoCrW alloys produced by Laser Powder Bed Fusion (L-PBF) as an additive manufacturing (AM) technology. Ti6Al4V and CoCrW alloys are attractive for medical application. The complex examination of porosity for these alloys needs the quantification of morphological and dimensional characteristics. Quantification of porosity was realized on non-etched samples. Quantitative image analysis was used to describe the dimensional and morphological porosity characteristics. The pores were evaluated by Image pro plus software. The results show the significant inhomogeneity of the morphology and distribution, as well as the pore size in the investigated materials and underline the importance of pore structure for the controlling mechanism of the mechanical response.

18

Erosion Wear Characteristics of Novel AMMC Produced Using Powder Metallurgy

Behera Rajesh Kumar, Samal Birajendu Prasad, Panigrahi Sarat Chandra, Parida Pramod Kumar, Muduli Kamalakanta, Muhammad Noor, Das Nitaisundar, Abd Rahim Shayfull Zamree

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

1027--1032

EN

Currently, the world of material requires intensive research to discover a new-class of materials those posses the properties like lower in weight, greater in strength and better in mechanical properties. This led to the study of light and strong alloys or composites. This study focuses to produce current novel aluminium composite with an appreciable density, good machinable characteristics, less corrosive, high strength, light weight and low manufacturing cost product. In this research, an aluminium metal matrix composites (AMMC) (Al-0.5Si-0.5Mg-2.5Cu-15SiC) was developed using the metallurgical powdered method and subjected to the investigation of erosion wear characteristics. Here the solid particle erosion test was conducted on AMMC samples. The article presents, the design of Taguchi experiments and statistical techniques of erosion wear characteristics and the behaviors of the composite. The rate of erosion wear found to decrease with increasing impact angle, regardless of the rate of impact. With higher impact velocity erosion rate increases but decreases with stand of distance.

19

Testing of Sinters Made of Copper Powders Coated with Carbon Structure Containing Graphene

Rajkowski Kamil, Majewski Tomasz

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2021

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Vol. 12, Nr 2 (44)

75--90

EN

This paper presents the results of preliminary tests on specimens made from mixtures of dendritic copper powder (CuE) with the graphene-coated copper powder (CuG) in a range from 20% to 100% (CuG). The properties of the powder mixtures, green compacts and sinters were determined. To study the properties of the powder mixtures, the following tests were carried out: a measurement of the CuG powder grain size after the grinding process, measurements of the bulk density and tap density of the prepared powder mixtures. The porosity of the produced green compacts and the sinters was calculated as well as the densification capabilities of the powder mixtures by die pressing, cold isostatic pressing and sintering in a reducing atmosphere were tested. Moreover, the nature of the porosity formation was analysed using an optical microscope and the Brinell hardness was determined. The measured Brinell hardness was in the range of 17 HB for sinters made from CuG to 34 HB for sinters made from a 20% CuG powder mixture. More than six hundred measurements that were made in this study show that the high CuG content in the powder mixture reduces the hardness of the sinters as well as increase their porosity.

PL

W artykule zostały przedstawione wyniki wstępnych badań próbek wykonanych z mieszanin proszku miedzi dendrytycznej (CuE) z proszkiem miedzi pokrytym strukturą węglową zawierającą grafen (CuG) w przedziale od 20% do 100% (CuG). W ramach badań określone zostały właściwości mieszaniny proszków, wyprasek oraz spieków, składające się na opis badanego materiału. W celu zbadania właściwości mieszanin proszków zostały wykonane następujące badania: pomiar wielkości ziaren proszku CuG po procesie rozdrabniania, pomiar gęstości nasypowej oraz nasypowej z usadem przygotowanych mieszanin. Obliczono porowatość wytworzonych wyprasek, a następnie spieków oraz sprawdzono możliwości zagęszczania się otrzymanych mieszanin poprzez zastosowanie prasowania matrycowego, prasowania izostatycznego na zimno oraz spiekania w atmosferze redukującej. Dokonano również analizy powierzchni wykonanych próbek pod kątem charakteru powstałych porów za pomocą mikroskopu optycznego oraz określono twardość próbek metodą Brinella. Zmierzona twardość próbek mieści się w zakresie od 17HB dla spieków wykonanych wyłącznie z CuG do 34HB dla spieków wykonanych z mieszanki zawierającej 20% CuG. W ramach badań wykonanych zostało ponad sześćset pomiarów, których wyniki pokazują, że duża zawartość CuG w mieszaninie proszkowej zmniejsza twardość otrzymanych z niej spieków oraz zwiększa ich porowatość.

20

Efekt mechanicznej syntezy na mikrostrukturę kompozytów na osnowie miedzi umacnianych cząstkami azotku tytanu. Wytwarzanie i właściwości Cu-5% wag. TiN

Franczak Aleksandra, Karwan-Baczewska Joanna

Hutnik, Wiadomości Hutnicze

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2021

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Vol. 88, nr 2

2--7

PL

W artykule przedstawiono sposób wytworzenia kompozytów na osnowie miedzi umacnianych dodatkiem 5% wag. azotku tytanu. W tym celu zastosowano proces mechanicznej syntezy (MA) i iskrowego spiekania plazmowego (SPS). Zaobserwowano, że 10-cio godzinny proces mechanicznej syntezy doprowadził do utworzenia się struktury płatkowej mieszanki kompozytowej Cu-TiN. Cząstki azotku tytanu znajdują się wewnątrz plastycznej osnowy, jednakże ich rozmieszczenie nie jest w pełni równomierne. Artykuł przedstawia mikrostrukturę mieszanki kompozytowej uzyskanej zarówno podczas mechanicznej syntezy jak i po jej zakończeniu, a także mikrostrukturę uzyskanych spieków po procesie iskrowego spiekania plazmowego. Zamieszczono wyniki dotyczące gęstości, twardości i przewodności elektrycznej kompozytów.

EN

In the presented work, Cu matrix composites reinforced with 5% wt. of TiN were prepared by mechanical alloying (MA) and spark plasma sintering (SPS) method. During experiments it was observed that 10 hours of MA lead to a flake-like particle morphology. Titanium nitride particles are located inside copper matrix but their distribution is not completely homogeneous. This article shows microstructure of the powders during and after MA as well as SPS method. Density, hardness and electrical conductivity of the composites are also presented.