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1

Microstructure and properties of the hot work tool steel gradient surface layer obtained using laser alloying with tungsten carbide ceramic powder

Jonda E., Labisz K., Dobrzański L. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 73, nr 2

214--221

EN

Purpose: The aim of the paper is to present the innovatory investigation results of the impact of laser treatment consisting of multiple remelting and alloying using tungsten carbide ceramic powder on the microstructure and properties of hot work tool steel X40CrMoV5-1 surface layer. Design/methodology/approach: Laser heat treatment allows the production of gradient surface layer with a thickness reaching from of tenths of a millimetre even to few millimetres with specific functional properties, including high hardness and abrasion resistance, while maintaining the properties of the substrate material. Findings: Preliminary investigations of the effects of laser radiation on steel surface have showed, that in the surface layer there occur changes concerning the microstructure as well as in the chemical composition different from those occurring during conventional heat treatment. Research limitations/implications: There was determined the effect of laser power on the remelting depth, the depth of the heat affected zone and the width of the laser tray face. There was also measured and compared to the hardness and roughness of the steel processed by remelting with different process parameters. Practical implications: The current application areas for hot work tool steels are constantly growing, and the intensive development of techniques requires the use of new technologies, what leads to production of specific surface layer on materials, in order to meet the extremely difficult working conditions of modern tools. Originality/value: The effect of a HPDL laser melting on the hot work tool steel, especially on their structure and hardness has been studied.

2

Fractographic and structural peculiarities of laser weld-on layers with a maraging alloy

Shtarbakov V., Stavrev D.

Archives of Materials Science and Engineering

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2015

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Vol. 75, nr 1

12--17

EN

Purpose: Purpose of the present paper is to investigate the fractographical peculiarities of the layers welded-on the surface of 30CrMoV12-28 (DIN) tool steel by laser with additional material of marraging alloy. Design/methodology/approach: The operation was accomplished on an AL 200 automatic weld-on machine with an Nd:YAG pulse resonator providing a beam of 1064 nm wavelength. The mean power output of the pulse was 200 W and the maximum peak power output was 10 kW. The operating frequency was 20 Hz. The diameter of the laser beam focused on the sample surface was 0.6 mm. The weld-on maraging alloy featured contents of 0.02C - 0.2Si - 0.2Mn - 2Cr - 19.3Ni - 0.4V - 4.7Mo - 14.5Co - 0.25Al, wt%. Studied were the fractures obtained at three - point bending of the layer upon weld-on followed by two - hour age hardening at temperatures of 550 and 600°C. Findings: The nature of deformation along the weld-on layer under tensile impact strains was studied, the destruction being trans-crystalline determined by the prevailing plastic deformation.The destruction after age hardening at temperatures of 550 and 600°C was of the mixed and trans-crystalline type. The results of the processes of dispersion hardening and those of the beginning of coherent phase formation were connected with the main matrix of the inter-metallic compounds based on NiAl and NiMo. The condition of the structure was characterized by the so called “pit” curved surface of the destruction. The analysis of the fractures along with the EDS analysis showed that the inter-metallic phases formed in the process of secondary hardening of the material in the weld-on layer were of the NiAl, NiMo and Ni3Mo type. Research limitations/implications: For more correct determination of phase contents in depth of hardened layers have to be used XRD techniques. Practical implications: Taking into account the high value of the materials used for producing press-forming dies it is of vital importance to find possibilities for considerable increase of the lifecycle of casting moulds. Laser surface welding-on by using of maraging alloy as additional material is cost effective technology for repairing of press-forming dies.

3

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.

4

Unique properties, development perspectives and expected applications of laser treated casting magnesium alloys

Dobrzańska-Danikiewicz A. D., Tański T., Domagała-Dubiel J.

Archives of Civil and Mechanical Engineering

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2012

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Vol. 12, no. 3

318--326

EN

The purpose of the article is to present the unique properties of casting magnesium alloys subjected to surface treatment with the high power diode laser, to indicate the development outlooks of the technology and to present its application opportunities in the automotive industry. The laser alloying and cladding of hard titanium and tungsten carbides particles into the substrate surface improves the mechanical and functional properties of the investigated materials to a satisfactory extent. In view of the demand from the automotive sector for components and parts made of lightweight alloys, the development prospects of their effective manufacturing technology meeting the expected product properties, including surface laser treatment, were evaluated to be very high.

5

Foresight methods application for evaluating laser treatment of hot-work steels

Dobrzańska-Danikiewicz A. D., Jonda E., Labisz K.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 43, nr 2

750--773

EN

Purpose: The purpose of this article is to evaluate the strategic growth perspectives of laser treatment of X40CrMoV5-1 and 32CrMoV12-28 hot-work alloy tool steels using NbC, TaC, TiC, VC and WC carbide powders. The criterion assumed for dividing the technologies into groups was the powder type; thus, five groups were selected to realised researches. Design/methodology/approach: As a part of the foresight-materials science researches, a dendrological matrix of technology value, a meteorological matrix of environment influence, and a matrix of strategies for technologies were elaborated, the strategic development tracks were determined, and materials science experiments were conducted using a scanning electron microscope, an optical microscope, a transmission electron microscope, a microhardness tester, a scratch tester, an X-ray diffractometer, an electron microprobe X-ray analyzer and a device for testing of heat fatigue and abrasive resistance. Also, technology roadmaps were prepared. Findings: The researches conducted demonstrated huge potential and attractiveness of the analyzed technologies, compared to others, and the promising properties improvement of the tested surface layers, as a result of laser surface treatment. Research limitations/implications: Researches concerning laser treatment of hot-work alloy tool steels constitute a part of a larger research project aimed at identifying, researching, and characterizing the priority innovative technologies in the field of materials surface engineering. Practical implications: The presented results of experimental materials science researches prove the significant positive impact of laser treatment on the structure and the properties of hot-work alloy tool steels, which justifies including them in the set of priority innovative technologies recommended for use in small and medium enterprises and in other business entities. Originality/value: The value of this article lies in the fact that it determines the value of laser treatment of hot-work alloy tool steels compared to other technologies and identifies the recommended strategic development tracks and technology roadmaps for them, taking into account the impact of such treatment on hardness, abrasion resistance, and coarseness of the tested surface layers.

6

Laser shock processing of an austenitic stainless steel

Rozmus-Górnikowska M., Kusiński J., Blicharski M.

Archives of Metallurgy and Materials

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2010

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Vol. 55, iss. 3

635-639

EN

The aim of this work was to examine the effect of laser shock processing (LSP) on the morphology, microstructure and surface layer properties of an X5CrNi18-10 austenitic stainless steel. The laser shock processing was accomplished by a high-power Q-switched Nd:YAG laser, operating in a 1.064 m wavelength range, with laser power density of 1 GW/cm2 and pulse duration of 18 ns. The microstructure and phase composition of the laser treated surface layer of the material were analyzed by light, scanning and transmission electron microscopy as well as by X-ray diffractometry. The X-ray diffractometer was also use to determine the value and level of residual stresses in the treated surface layer. It has been found that the laser shock processing causes significant plastic deformation and generate compressive stresses in the treated surface layer.

PL

W pracy przedstawiono wpływ laserowej obróbki odkształcającej na morfologię, mikrostrukturę i własności warstwy wierzchniej stali austenitycznej X5CrNi18-10. Laserowe odkształcanie przeprowadzono za pomocą lasera impulsowego ReNOVALaser Nd:YAG z modulacją Q, przy gęstości mocy 1 GW/cm2 i czasie trwania impulsu 18 ns. Do oceny wpływu laserowego odkształcenia na mikrostrukturę i skład fazowy warstwy wierzchniej wykorzystano mikroskopię optyczna, elektronowa skaningowa i transmisyjna jak również rentgenowska analizę fazowa. Pomiar naprężeń w warstwie wierzchniej przeprowadzono za pomocą dyfraktometru rentgenowskiego. Wykazano, że laserowa obróbka odkształcajaca powoduje odkształcenie plastyczne i wprowadza naprężenia ściskające do warstwy wierzchniej badanej stali austenitycznej.

7

Laser shock peening of a Ti6Al4V titanium alloy

Rozmus M., Kusiński J., Blicharski M., Marczak J.

Archives of Metallurgy and Materials

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2009

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Vol. 54, iss. 3

665-670

EN

The effect of the Laser Shock Peening (LSP) on the microstructure and properties of the surface layer of Ti6Al4V alloy has been studied. Laser shock processing was accomplished by a high-power Q-switched Nd:YAG laser, operating in a 1,064 µm wavelength range. The laser power density was 1 GW/cm2 and a puls duration 18 ns. Before the laser processing the material was covered by a 50 µm absorption layer and 3 mm layer of water. Investigations of modified surface layer were carried out by scanning (SEM) and transmission electron microscopy (TEM). The chemical composition of treated surface was determined by Energy Dispersive Spectrometry (EDS), attached to the SEM. The mechanical properties (hardness and Young modulus) were determined by nanohardness measurements using a pyramidal Berkovich diamond nanoindentor. It was found that the LSP process was not purely mechanical but thermo-mechanical and lead to the formation of the surface layer composed of three well defined zones: external – oxidized with cracks and porosity, central zone - martensitic and internal – deformed, with high dislocation density level.

PL

W pracy przedstawiono wpływ laserowej obróbki odkształcającej na mikrostrukturę i własności warstwy wierzchniej stopu tytanu Ti6Al4V. Proces laserowego odkształcania przeprowadzono za pomocą lasera impulsowego o dużej gęstości mocy ReNOVALaser Nd:YAG z modulacja Q. Stosowano długość fali 1,064 µm. Gestosc mocy wynosiła 1 GW/cm2, a czas trwania impulsu 18 ns. Przed procesem laserowego odkształcania powierzchnia stopu pokryta została absorpcyjną farbą o grubości 50 µm oraz warstwą wody o grubości 3 mm. Wpływ laserowej obróbki powierzchniowej na mikrostrukturę stopu Ti6Al4V zbadano za pomocą skaningowego (SEM) oraz transmisyjnego mikroskopu elektronowego (TEM). Analizę chemiczną wykonano za pomocą spektroskopii promieniowania rentgenowskiego z dyspersją energii (EDS). Własności mechaniczne (twardość i moduł Younga) zmierzono za pomocą nanotwardościomierza firmy CSM Instruments z wgłębnikiem Berkovicha. Wykazano, że przy tak dobranych parametrach laserowego odkształcania, proces LSP nie jest czysto mechaniczny ale termo-mechaniczny. Warstwa wierzchnia zbudowana jest z trzech stref: zewnętrznej – materiału przetopionego i utlenionego, charakteryzującego się porowatością i pęknięciami, środkowej strefy – martenzytycznej oraz wewnętrznej – materiału odkształconego, charakteryzującego się dużą gęstością dyslokacji.

8

Lasery i ich zastosowanie w inżynierii materiałowej

Kusiński J.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Mechanika

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2001

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Z. 75

27-46

PL

W pracy opisano zastosowanie laserów w inżynierii powierzchni ze szczególnym uwzględnieniem laserowego hartowania, przetapiania, stopowania oraz natapiania powłok, jak również w technologiach syntezy laserowej z wykorzystaniem zjawiska ablacji oraz w procesach spajania. Szczegółowo omówiono podstawy wymienionych procesów. Wzrost własności warstwy wierzchniej takich jak: twardość, wytrzymałość, odporność na erozje i korozje różnych, laserowo obrabianych materiałów (stali i żeliw), wiązano z przemianami fazowymi jakie zachodzą w materiałach w czasie szybkiego nagrzewania, przetapiania i chłodzenia, które prowadzą do rozdrobnienia mikrostruktury, otrzymywania faz metastabilnych oraz przesyconej w dodatki stopowe warstwy wierzchniej.

EN

The paper describes application of lasers in surface engineering, particularly in: laser hardening, melting, alloying and cladding, as well as in laser assisted synthesis of materials after ablation process and laser welding. The basics of every of the above-mentioned processes are discussed. Improvement of surface properties such as: hardness, strength, erosive and wear resistance of different materials/steels and cast irons) was connected to phase transformations taking place during rapid heating and cooling and causing microstructural refinement, appearance of metastable phases and microchemical changes in the surface layer

9

Koncepcja i rezultaty laserowej obróbki powierzchniowej stopów aluminium o temperaturze kriogenicznej.

Serbiński W.

Inżynieria Materiałowa

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2000

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R. XXI, nr 6

434-437

PL

W pracy przedstawiono koncepcję procesu i efekt oddziaływania wiązki lasera na powierzchnię stopów aluminium o temperaturze kriogenicznej. Uzyskano wyraźną zmianę mikrostruktury stopów AlSi10Cu2Mg1Ni1 i AlSi13Mg1CuNi w obszarze oddziaływania wiązki lasera oraz gwałtownego chłodzenia. W rezultacie ukształtowano warstwę wierzchnią stopów aluminium o twardości kilkakrotnie wyższej od ich twardości konwencjonalnej. Stwierdzono, iż głębokość przetopionej warstwy przy ciągłej 1,2 kW mocy lasera CO2 i stałej średnicy wiązki maleje wraz ze wzrostem prędkości przesuwu obrabianego elementu względem nieruchomego laserowego źródła ciepła.

EN

The method and equipment for laser treatment of the aluminium alloys at the cryogenic temperature have been proposed. The influence of laser beam on the surface layer of the aluminium alloys at cryogenic temperature is observed. Significant changes in microstructures of AlSi10Cu2Mg1Ni1 and AlSi13Mg1CuNi alloys in the laser treated zone were obtained. The surface layers of the hardness 211+280 HV0,05, several times higher than after conventional heat treatment of the aluminium alloys, were created. It was found, that the depth of the remelted layer for the laser CO2 with a power of 1,2 kW and the stable laser beam diameter decreased together with increase of the motion velocity of the treated element relative to the immovable laser beam.