Wyniki wyszukiwania - BazTech

1

Laser welding of stainless steel

Kurc-Lisiecka A., Lisiecki A.

Journal of Achievements in Materials and Manufacturing Engineering

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2020

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Vol. 98, nr 1

32--40

EN

Purpose: of this paper was to analyze the influence of the basic parameters of laser welding (i.e. laser beam power and welding speed, as well as energy input) of butt joints of the 2.0 mm thick stainless steel AISI 304 sheets on the weld shape and joint quality. Design/methodology/approach: The preliminary trials of simulated laser welding by melting the austenitic stainless steel sheets (the so called bead-on-plate welding), as well as the welding of the test butt joints, were carried out using the high-power diode laser (HPDL) ROFIN DL 020, without the additional material (the technique of autogenous welding). A crucial parameter that determines both the mechanical properties and the corrosive resistance of a joint (the region of a weld and HAZ - heat affected zone) in the case of stainless steels with austenitic structure is energy input, which should be kept at a minimum, and at the same time full penetration and a proper shape of the fusion zone should be ensured. The investigations included the macrostructure and microstructure observations by light microscopy, researches of mechanical properties in a static tensile test and also microhardness measurements made by Vickers method. Findings: The results have shown that it is possible to provide a proper shape of the weld of fine-grained structure and narrow heat affected zone, but it requires careful selection of the welding parameters, especially a low energy input. The microhardness measurements showed that the in case of welding the butt joints using the high-power diode laser in HAZ area a slight increase in microhardness to approx. 185HV0.2 compared to base material (160-169HV0.2) and a decrease in microhardness in the fusion zone (FZ) to approx. 140- 150HV0.2 have been observed. All welded sample broke from the joint during the testing at tensile stress between 585 MPa and 605 MPa with corresponding percentage elongation in the range of 45-57%. It can be found that the joints strength is not less than the strength of the base metal of 2.0 mm thick AISI 304 austenitic stainless steel sheet. Research limitations/implications: Studies of the weldability of stainless steels indicate that the basic influence on the quality of welded joints and reduction of thermal distortions has the heat input of welding, moreover the highest quality of welded joints of austenitic stainless steel sheets are ensured only by laser welding. Practical implications: The laser welding technology can be directly applied for welding of austenitic steel AISI 304 sheets 2.0 mm thick. Originality/value: Application of high power diode laser for welding of austenitic stainless steel AISI 304.

2

Napawanie laserowe tarcz zderzaków kolejowych brązem aluminiowym

Sitarz M., Kurc-Lisiecka A., Gamon W.

Stal, Metale & Nowe Technologie

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2017

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nr 9-10

80--84

PL

W artykule opisano wyniki badań procesu napawania laserowego powierzchni tarcz zderzaków kolejowych ze stali S355J2 proszkiem na bazie brązu aluminiowego. Próby napawania wykonano za pomocą lasera diodowego dużej mocy (HPDL) LDF 4000-30 firmy LaserLine o mocy maksymalnej 4,0 kW. Badania obejmowały również obserwacje metalograficzne wytworzonych warstw, badania ich odporności na zużycie ścierne i pomiary twardości. Stwierdzono, że w wyniku napawania laserowego tarcz zderzaków kolejowych ze stali S355J2 proszkiem brązu CuAl9Fe3 i laserem diodowym HPDL możliwe jest wykonanie wysokiej jakości napoin bez nieciągłości strukturalnych i o korzystnej, drobnoziarnistej strukturze dendrytycznej w obszarze napoiny. Wykazano również, że napawanie laserowe brązem aluminiowym zapewnia znaczący wzrost odporności na zużycie ścierne powierzchni czołowych tarcz zderzaków kolejowych i pozwala na wyeliminowanie konieczności okresowego ich smarowania.

EN

The paper presents the results of the study of the laser powder cladding of railway buffers heads made of the S355J2 steel by aluminium bronze-based powder. The high power diode laser (HPDL) LDF 4000-30, produced by LaserLine, with the maximum output power of 4.0 kW, was used for the cladding trials. The investigations included also the metallographic observations of the clad layers, wear behaviour and hardness measurements. It was found that it is possible to produce high-quality clad layers of the aluminium bronze CuAl9Fe3 on the steel substrate, without any internal imperfections, such as voids or structural discontinuities, and characterized by fine-grained dendritic structure in the fusion zone of the clad. It was also shown that the laser cladding of aluminium bronze provides a significant increase of wear resistance of buffer working surfaces and can also eliminate the need of periodical greasing of these surfaces.

3

Przyczyny pęknięć lutospoin w złączach różnoimiennych typu aluminium - ocynkowana stal niestopowa

Czupryński A., Janicki D.

Przegląd Spawalnictwa

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2016

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R. 88, nr 5

43--48

PL

W artykule przedstawiono wyniki badań dotyczących przyczyn pękania lutospoin w różnoimiennych złączach zakładkowych wykonanych laserem diodowym dużej mocy ROFIN DL 020 z użyciem materiału dodatkowego w postaci proszku aluminium, na przykładzie łączenia cienkiej blachy aluminiowej z blachą stalową pokrytą elektrolitycznie powłoką cynkową. Przedstawiono wyniki badań metalograficznych makroskopowych i mikroskopowych. Wskazano na problemy oraz przedstawiono sugestie dotyczące technologii lutospawania laserowego materiałów znacznie różniących się własnościami fizycznymi i składem chemicznym.

EN

A study on cracking phenomena during laser braze welding of dissimilar lap joints between aluminum thin plate and galvanized low carbon sheet steel is described. The experiments were carried out using a high power diode laser Rofin DL020 and aluminum powder as filler metal. Macro and microstructure analysis of the joints were analysed. Issues and problems in laser braze welding of materials having different chemical composition and physical properties are presented.

4

Comparison of the abrasion wear resistance of the laser alloyed hot work tool steels

Dobrzański L., Jonda E., Labisz K.

Archives of Materials Science and Engineering

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2012

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Vol. 55, nr 2

85-92

EN

Purpose: The paper presents the comparison of the abrasion wear resistance of the laser alloyed hot work tool steels X40CrMoV5-1 and 32CrMoV12-28. Design/methodology/approach: The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces. Findings: The performed investigations leads to the conclusions that for both types of steels - X40CrMoV5-1 and 32CrMoV12-28 the wear resistance measured using pin-on-disc, wear resistance test in the metal - metal arrangement, and wear resistance test in the metal - ceramic material arrangement, the wear resistance increases together with the hardness of the surface layer. This relationship is valid for all types of ceramic powders used. It is characteristic for the obtained surface layers, that the high roughness, multiple pores, irregularity, and flashes at the borders increases also together with the increasing of the laser power. Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: The alloyed layers which were formed on the surface of the hot work steels have shown significant improvement concerning properties. Good properties of the laser treatment make these layers suitable for various technical and industrial applications. Originality/value: A modification of tool steels surface using a laser beam radiation, as well as coating them with special pastes containing carbide particles allows the essential improvement of the surface layer properties - their quality and abrasion resistance, decreasing at the same time the surface quality, what is dependent on the processing parameters such as energy of impulse and the time of its work.

5

Hartowanie diodowym laserem dużej mocy

Pawłowicz W.

Obróbka Metalu

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2010

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nr 3

30--32

6

Structure changes and mechanical properties of laser alloyed magnesium cast alloys

Dobrzański L., Domagała J., Malara S., Tański T., Kwaśny W.

Archives of Materials Science and Engineering

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2009

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Vol. 35, nr 2

77-82

EN

Purpose: The aim of this work was to investigate structure and mechanical properties of the MCMgAl12Zn1 casting magnesium alloys after laser treatment. The laser treatment was carried out using a high power diode laser (HPDL). Design/methodology/approach: The laser processing of TiC, WC, SiC particles in MCMgAl12Zn1 and the resulted microstructures and properties are discussed in this paper. The resulting microstructure in the modified surface layer was examined. Phase composition was determined by the X-ray diffraction method using XPert device. The measurements of hardness after laser melt injection was also studied. Findings: Structure of the solidyifying material after laser alloying is characteristic with occurrences of areas with the diversified morphology, dependent on solidification rate of the magnesium alloys, is characteristic of structure of the solidified material after laser alloying. The MCMgAl12Zn1 casting magnesium alloys after laser alloying demonstrate similar hardness tests results, in reference to hardness of the alloys before their laser treatment. Research limitations/implications: In this research three powders (titanium carbide, tungsten carbide and silicon carbide) were used to reinforcing the surface of the MCMgAl12Zn1 casting magnesium alloys. Practical implications: High power diode laser can be used as an economical substitute for CO₂ and Nd:YAG lasers to modify the surface magnesium alloy by feeding the carbide particles. Originality/value: The originality of this work is applying of High Power Diode Laser for laser treatment of cast magnesium alloy consisting in fusion penetration of the hard particles of titanium, tungsten, and silicon carbides into the remelted surface layer of the alloy.

7

Laser surface treatment of the hot work tool steel alloyed with TaC and VC carbide powders

Dobrzański L. A., Jonda E., Klimpel A.

Archives of Materials Science and Engineering

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2009

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Vol. 37, nr 1

53-60

EN

Purpose: The paper presents investigation results of the structure and properties of alloying surface layer of the X40CrMoV5-1 hot work tool steel, using the high power diode laser HPDL. Tantalum and vanadium carbides powders were used for alloying and the X40CrMoV5-1 conventionally heat treated steel was used as reference material. Design/methodology/approach: Metallographic examinations of the material structures after laser alloying surface layer were made on light microscope and transmission electron microscope. The resistance research has been done with the use of the pin-on-disc method. Hardness tests were made with Rockwell method in C scale. Findings: It was found out in examinations of the surface layer that it can be possible to obtain high quality top layer with better properties compared to material after a standard heat treatment. Research limitations/implications: In this research two powders (TaC and VC) were used for alloying of the surface layer of investigated steel. Practical implications: The structure as well as improvement of mechanical properties is a practical aim of this work as well as improvement of hardness as a very important properties for practical use. Originality/value: The research results of this type of heat treatment show that there is a possibility of applying the worked out technology to manufacturing or regeneration of chosen hot working tools.

8

Laser surface treatment of cast magnesium alloys

Dobrzański L., Domagała J., Tański T., Klimpel A., Janicki D.

Archives of Materials Science and Engineering

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2009

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Vol. 35, nr 2

101-106

EN

Purpose: The goal of this work was to investigate influence of laser treatment on structure and properties MCMgAl3Zn1, MCMgAl6Zn1, MCMgAl9Zn1 and MCMgAl12Zn1 cast magnesium alloys. Design/methodology/approach: Tests were made on the experimental MCMgAl3Zn1 MCMgAl6Zn1 MCMgAl9Zn1 and MCMgAl12Zn1 casting magnesium alloys. Laser treatment was made using the Rofin DL020 HPDL high power diode laser in the argon shield gas cover with the technique of the continuous powder supply to the remelted pool area. Findings: Investigations of the surface layers carried out confirm that laser treatment of the surface layer of the Mg-Al-Zn casting magnesium alloys is feasible using the HPDL high power diode laser ensuring better properties compared to alloys properties after the regular heat treatment after employing the relevant process parameters. Occurrences were found based on the metallographic examinations of the remelted zone (RZ) and the heat affected zone (HAZ) in alloyed surface layer of the investigated casting magnesium alloy. Research limitations/implications: This investigation presents different laser power and in this research was used two powders, namely tungsten-, and titanium carbide. Practical implications: Reinforcing the surface of cast magnesium alloys by adding TiC and WC particles is such a possible way to achieve the possibilities of the laser melt injection process, which is a potential technique to produce a Metal-Matrix Composite (MMC) layer in the top layer of a metal workpiece. Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten- and titanium carbide.

9

Laser treatment of the surface layer of 32CrMoV12-28 and X40CrMoV5-1 steels

Dobrzański L. A., Labisz K., Jonda E.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 29, nr 1

63-70

EN

Purpose: This work presents the investigation results of laser remelting and alloying especially the laser parameters and its influence on the structure and properties of the surface of the 32CrMoV12-28 and X40CrMoV5-1 hot work steels, using the high power diode laser (HPDL). In this paper there are presented the investigation results of mechanical properties and microstructure with ceramic particle powders VC vanadium carbide and WC tungsten carbide. The purpose of this work was also to determine the laser treatment conditions for surface layer treatment of the investigated steels. Design/methodology/approach: The purpose of this work was the determination of technological conditions for alloying and remelting of the surface layer particularly the laser power. There is studying the influence of treatment on the remelting depth of the surface layer to achieve high layer hardness for protection of the steel and also make the surface more resistant for work. Findings: As a result structure changes in form of fragmentation were determined. For alloying the tungsten carbide and vanadium carbide powders were used. Two phases of carbides, VC and WC, were observed. Research limitations/implications: The remelted layers which were formed on the surface of the investigated hot work steel were examined metallographically and analyzed using a hardness and micro hardness testing, X-ray diffraction, EDS microanalysis, electron scanning microscope. Practical implications: This work helps to use the new developed laser treatment technique for alloying and remelting of hot work tool steel tools for hot working conditions. Originality/value: The originality of this work is based on applying of High Power Diode Laser for improvement of steel mechanical properties as well the thermal fatigue and wear resistance.

10

Laser surface treatment of magnesium alloy with WC powder

Dobrzański L., Domagała J., Tański T., Klimpel A., Janicki D.

Archives of Materials Science and Engineering

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2008

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Vol. 30, nr 2

113-116

EN

Purpose: The aim of this work was to improve the surface layer cast magnesium alloy EN-MCMgAl6Zn1 by laser surface treatment. The purpose of this work was also to determine the laser treatment parameter. Design/methodology/approach: The laser treatment of an EN-MCMgAl6Zn1 magnesium alloy with alloying WC powders was carried out using a high power diode laser (HDPL). The resulting microstructure in the modified surface layer was examinated using scanning electron microscopy. Phase composition was determined by the X-ray diffraction method using the XPert device. The measurements of microhardness of the modified surface layer was also studied. Findings: The morphology of the alloyed zone are dendrites. Microhardness of laser surface melted layer was significantly improved as compared to alloy without laser treatment. Research limitations/implications: This investigation presents different speed rates feed by one process laser power and in this research was used one powder with the particle size over 5µm. Practical implications: The results obtained in this investigation were promising to compared other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd:YAG and CO2 to improve the surface magnesium alloy by feeding the carbide particles. Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten carbide.

11

Characteristic of Mg-Al-Zn alloys after laser treatment

Dobrzański L. A., Domagała J., Tański T., Klimpel A., Janicki D.

Archives of Materials Science and Engineering

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2008

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Vol. 34, nr 2

69-74

EN

Purpose: The structure and the properties of casting magnesium alloy EN-MCMgAl3Zn1, EN-MCMgAl6Zn1, EN-MCMgAl9Zn1 and EN-MCMgAl12Zn1 after laser surface treatment are presented in this paper. The aim of this work was to improve the surface layer cast magnesium Mg-Al-Zn by melting and feeding of TiC particle on the surface. The purpose of this work was to determine the laser treatment parameter. Design/methodology/approach: The experiments were performed using high power diode laser. The laser treatment of an EN-MCMgAl3Zn1, EN-MCMgAl6Zn1, EN-MCMgAl9Zn1, EN-MCMgAl12Zn1 magnesium alloy with alloying TiC powders was carried out using a high power diode laser (HPDL). The resulting microstructure in the modified surface layer was examinated using scanning electron microscopy. Phase composition was determined by the X-ray diffraction method using the XPert device. The measurements of hardness of the modified surface layer was also studied. Findings: The alloyed region has a fine microstructure with hard carbide particles. Hardness of laser surface alloyed layer with TiC particles was significantly improved as compared to alloy without laser treatment for EN-MCMgAl3Zn1 and EN-MCMgAl6Zn1 alloys. Research limitations/implications: In this research one powder - TiC was used with the particle size over 6 µm. This investigation presents different speed rates feed and different laser power value for four type of magnesium alloys. Practical implications: The results obtained in this investigation were promising compared to other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd:YAG and CO2 to improve the surface magnesium alloy by feeding the carbide particles. Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using titanium carbide.

12

Thermal analysis of nozzle for powder feeding in High Power Diode Laser (HPDL) powder surfacing

Klimpel A., Janicki D., Lisiecki A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

463-466

EN

Purpose: Purpose of these researches was to determine the influence of High Power Diode Laser (HPDL) powder surfacing parameters, material type and shape of the nozzle for powder feeding on the temperature field of the nozzle. Design/methodology/approach: Different materials for manufacturing of the nozzle for powder feeding during HPDL powder surfacing and different shapes of the nozzle were tested to establish the optimum shape and select the material that ensure lowest heating of the nozzle. Reflection coefficient of the infared laser radiation of 808 nm for the tested materials were determined as a function of a temperature. Temperature of the nozzle tip was measured and determined as a function of surfacing parameters. Life time of the different nozzles was determined. Findings: It was shown that the nozzle made of copper body and thin-walled tube made of austenitic stainless steel ensures much higher life time of the nozzle and also higher process efficiency compared with nozzle made of copper. Research limitations/implications: It was found that decreasing the distance from the nozzle tip of thin-walled tube made of austenitic stainless steel to the weld pool surface resulted in increasing of the process efficiency but too short distance is the reason of extensive heating of the nozzle. Originality/value: The optimized shape of the powder feeding nozzle made of thin-walled tube made of austenitic stainless steel guarantee unlimited lifetime of the nozzle and high surfacing efficiency over 95%.

13

Study of laser welding of copper sheets

Klimpel A., Rzeźnikiewicz A., Janik Ł.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

467-470

EN

Purpose: Purpose of this research is to study laser autogeneous welding process of short seam beads and fillet welds of lap joints of oxygen-free copper sheets 1.0 [mm] thick. On the bases of results of quality assessment it was proved that high power diode laser (HPDL) welded lap joints of copper sheet provide mechanical properties on the level of parent material. Design/methodology/approach: Short seam beads and fillet welds of lap joints of oxygen-free copper sheets 1,0 [mm] thick were tested, to establish the optimum parameters of high power diode laser autogeneous welding process. Findings: It was shown that there is very narrow range of optimum HPDL autogeneous welding parameters of short seam beads and fillet welds of lap joints of oxygen-free copper sheets 1,0 [mm] parameters. It was proved that high power diode laser (HPDL) autogeneous welded lap joints provide mechanical properties on the level of parent material. Practical implications: It is possible to produce high quality short seam bead and fillet weld lap joints of oxygen-free copper sheets 1.0 [mm] thick. It was proved that high power diode laser (HPDL) autogeneous welded lap joints provide mechanical properties on the level of parent material. Originality/value: The optimum HPDL autogeneous welding parameters of short seam beads and fillet welds of lap joints of oxygen-free copper sheets 1.0 [mm] parameters makes possible to produce high quality laser autogeneous welded lap joints of copper sheets 1.0 [mm] thick.

14

Mechanical and tribological properties of the laser alloyed surface coatings

Dobrzański L. A., Piec M., Bonek M., Jonda E., Klimpel A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

235-238

EN

Purpose: Improvement of surface properties of X38CrMoV5-3 is one of the goals set to the research institutions active in this paper. Design/methodology/approach: Remelting and alloying of surface layers were made using the HPDL high power diode laser Rofin DL 020 in the laser power range of 1.2-2.3 kW. Abrasion wear resistance tests were made in the metal-ceramic material arrangement (ASTM-G65), and also in the metal-metal one. Findings: All employed carbides cause hardness and microhardness increase of the surface layer of the investigated steel, and in most cases abrasion wear resistance increase. The investigations carried out indicate that the best mechanical properties are displayed by the surface layers of steel alloyed with carbides: TaC, NbC, and VC; whereas, the best tribological properties are displayed by surface layers allowed with vanadium carbide, compared to the conventionally heat treated steel. Improvement of mechanical properties and abrasion wear resistance grow with the increase of the laser power. Research limitations/implications: The material behavior for the HPDL processing has been found to be different from the other high-power lasers in the following aspects: fewer cracks and less spallation for surface glazing/sealing, more uniform melt/heating zones, smoother surface, better beam absorption for metallic materials, more consistent and repeatable. Practical implications: The research results indicate to the feasibility and purposefulness of the practical use of remelting and alloying with the tungsten carbide using the high power diode laser for manufacturing and regeneration of various tools from the X38CrMoV5-3 hot-work tool steel. Originality/value: Possibilities of increasing the functional properties of hot-work alloy tool steels by modification of their chemical composition additional of ceramic particles in a conventional way are very limited already.

15

Laser welding of butt joints of austenitic stainless steel AISI 321

Klimpel A., Lisiecki A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 25, nr 1

63-66

EN

Purpose: of this paper: A study of an automated laser autogenous welding process of butt joints of austenitic stainless steel AISI 321 sheets 0.5 [mm] and 1.0 [mm] thick using a high power diode laser HPDL has been carried out. Design/methodology/approach: Influence of basic parameters of laser welding on shape and quality of the butt joints and the range of optimal parameters of welding were determined. Findings: It was showed that there is a wide range of laser autogenous welding parameters which ensures high quality joints of mechanical strength not lower than the strength of the base material (BM). The butt joints of austenitic steel AISI 321 sheets welded by the HPDL diode laser at optimal parameters are very high quality, without any internal imperfections and the structure and grain size of weld metal and HAZ is very small and also the HAZ is very narrow and the fusion zone is very regular. Research limitations/implications: Studies of the weldability of stainless steels indicate that the basic influence on the quality of welded joints and reduction of thermal distortions has the heat input of welding, moreover the highest quality of welded joints of austenitic stainless steel sheets are ensured only by laser welding. Practical implications: The technology of laser welding can be directly applied for welding of butt joints of austenitic steel AISI 321 sheets 0.5 and 1.0 [mm] thick. Originality/value: Application of high power diode laser for welding of austenitic stainless steel AISI 321.

16

Improvement of the hot work tool steel surface layers properties using a high power diode laser

Dobrzański L. A., Piec M., Klimpel A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 21, nr 1

13-22

EN

Purpose: The purpose of this research paper is focused on the X38CrMoV5-3 hot work tool steel surface layers properties using HPDL laser. Design/methodology/approach: The aim of this research paper is to present deposition technologies, investigation of structure and properties of the X38CrMoV5-3 hot work tool steel alloying with ceramic particles using high power diode laser HPDL. Selection of laser operating conditions is discussed, as well as beam face quality after remelting, hardness, micro hardness test, wear resistant, EDX, TEM and X-ray microanalysis results. Findings: The structure of the solidified material after the laser remelting is characterized by the diversified morphology connected with the multiple changes of the crystal growth direction from little dendrites to tiny equiaxed grains in the near-surface zone. The main axes of the dendrites are directed according to the heat abstraction directions on the border of the solid and liquid phases with the carbides' clusters arranged according to the whirls caused by a convectional movement in the pool of the metallic liquid as well as partly unremelted conglomerates NbC, TaC, VC, WC and TiC as a melting material in the middle area of the remelted zone. Research limitations/implications: Laser technique features the especially promising tool for solving the contemporary surface engineering problems thanks to the physical properties of the laser, making it possible to focus precisely the delivered energy in the form of heat in the surface layer. Practical implications: Practical implications are: regeneration and manufacturing of various tools from the X38CrMoV5-3 hot-work tool steel. Originality/value: The laser treatment as a part of the new generation techniques applied in metal surface technology.

17

Computer aided structure prediction of OH18N9 and S235JR steels laser welded joints

Klimpel A., Kik T., Górka J.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 21, nr 1

83-86

EN

Purpose: of these researches was to investigate possibilities of joining materials with different chemical composition and properties. CAW software to prediction of joints structure was used. Design/methodology/approach: the quality of single- and double sided joints was assessed by metallographic examinations, hardness tests, tensile and bending tests. Findings: a computer aided structure prediction was tested by metallographic examinations and hardness tests. Because of possibility of use these type of joints in medical equipment production tensile and bending tests and also corrosion resistance tests were performed. Research limitations/implications: for complete information about tested different chemical composition and properties materials joints it is needed to check others materials in place of S235JR carbon steel. Practical implications: result of this paper is an information that is possible to join materials with different chemical composition and properties materials with different chemical composition and properties. It also possible to precise predict structure of weld using computer software. Originality/value: the researches were provided for welding materials used in medical equipment producing. Welded joints were tested for a corrosion resistance in typical disinfectants used in medical conditions. At the beginning computer prediction was used.

18

Mechanical and tribological properties of the surface layer of the hot work tool steel obtained by laser alloying

Dobrzański L. A., Jonda E., Križ A., Lukaszkowicz K.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 7

389-396

EN

Purpose: The paper presents results on the mechanical and tribological properties examinations of the X40CRMoV5-1 hot work alloy tool steel alloyed with carbide powders using the high power diode laser (HPDL). Design/methodology/approach: Metallographic examinations of the material structures after laser alloying of their surface layer were made on light microscope. The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces. Hardness tests were made with Rockwell method in C scale on specimens subjected to the standard heat treatment and alloyed using the high power diode laser at various parameters. X-ray diffraction (XRD) technique was used to investigate crystalline structure and phases in the layers. Findings: Metallographic examinations carried out on the light microscope confirm that the structure of the material solidifying after laser remelting is diversified, which is dependant on the solidification rate of the investigated steels. The investigations carried out made it possible to state that due to the heat treatment and remelting of the X40CrMoV5-1tool steel with the WC, TaC or TiC powders it is possible to obtain the high quality surface layer with no cracks and defects and with hardness significantly higher than the substrate metal. Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: The alloyed layers which were formed on the surface of the hot work steel have shown significant improvement. Good properties of the laser treatment make these layers suitable for various technical and industrial applications. Originality/value: A modification of tool steels surface using a laser beam radiation, as well as coating them with special pastes containing carbides particles such as tungsten, tantalum and titanium allows the essential improvement of the surface layer properties-their quality and abrasion resistance, decreasing at the same time the surface quality.

19

Structure and tribological behavior of surface layer of laser modified X40CrMoV5-1 steel

Dobrzański L. A., Jonda E., Lukaszkowicz K., Križ A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

343--346

EN

Purpose: The paper presents the effect of alloying with WC, TaC and TiC on structure and mechanical properties of the X40CrMoV5-1 steel surface layer using the HPDL (High Power Diode Laser). Design/methodology/approach: The microstructure of the alloyed layers which were formed on the surface of the investigated hot work steel was examined using optical microscope. The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces. X-ray diffraction (XRD) technique was used to investigate crystalline structure and phases in the layers. Findings: The metallographic investigations on light microscope show that during alloying the X40CrMoV5-1 hot work tool steel with the WC, TaC and TiC powder layer the obtained run face is characteristic of the high roughness, multiple pores, irregularity, and flashes at the borders. The changes of the surface layers hardness formed as a result of remelting and alloying with ceramic powders containing carbides are accompanied with the increased tribological properties. Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: The alloyed layers which were formed on the surface of the hot work steel have shown significant improvement. Good properties of the laser treatment make these layers suitable for various technical and industrial applications. Originality/value: Structural and tribological behaviour of surface layer achieved by alloying and remelting using high diode power laser and selected ceramic powders were compared.

20

Structure and properties of surface layers obtained by alloying of the hot work tool steels

Dobrzański L. A., Polok A., Jonda E.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

329--332

EN

Purpose: The aim of the present work was to study the microstructure and properties produced after laser alloying of the 55NiCrMoV7 and X40CrMoV5-1 an alloy hot-work tool steels. Design/methodology/approach: Structure investigation was performed using the light microscope Leica MEF4A supplied by Zeiss. Phase composition and crystallographic structure were determined by the X-ray diffraction method using the DRON 2.0. The measurements of microhardness have been performed using Shimadzu microhardness intender equipped with electronic sensor that allows the direct readout of the hardness values. Findings: The metallographic investigations on light microscope show that steel after laser remelting can be characterized by a dendrite structure. Metallographic examinations on the scanning microscope with the EDX attachment confirm the occurrence of the niobium carbides in the surface layer of the investigated steels. Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: The surface layer of the hot work steel alloyed with ceramic powder have good properties and make possibility for uses it in various technical and industrial applications. Originality/value: The microstructure and properties of the surface layer of the 55NiCrMoV7 and X40CrMoV5-1 hot-work tool steels alloying with ceramic powder were compared.