scholarly journals Heat Treatment and Formation of Magnetocaloric 1:13 Phase in LaFe11.4Si1.2Co0.4 Processed by Laser Beam Melting

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 773 ◽  
Author(s):  
Jwalant Kagathara ◽  
Sandra Wieland ◽  
Eric Gärtner ◽  
Volker Uhlenwinkel ◽  
Matthias Steinbacher
Keyword(s):  
Heat Treatment ◽  
Laser Beam ◽  
Entropy Change ◽  
Experimental Investigations ◽  
Cast Material ◽  
Cooling Systems ◽  
Laser Beam Melting ◽  
Conventional Heat Treatment ◽  
Magnetocaloric Properties ◽  
Short Time

In recent years, magnetocaloric materials have been extensively studied as materials for use in alternative cooling systems. Shaping the magnetocaloric material to thin-walled heat exchanger structures is an important step to achieve efficient magnetocaloric cooling systems. In the present work, experimental investigations were carried out on the heat treatment of LaFe11.4Si1.2Co0.4 alloy processed by Laser Beam Melting (LBM) technology. Due to the rapid solidification after melting, LBM results in a refined micro structure, which requires much shorter heat treatment to achieve a high percentage of magnetocaloric 1:13 phase compared to conventional cast material. The influence of the heat treatment parameters (temperature, time, and cooling rate) on the resulting microstructure has been extensively studied. In addition to the conventional heat treatment process, induction technology was investigated and the results were very promising in terms of achieving good magnetocaloric properties after short-time annealing. After only 15 min holding time at 1373 K, the magnetic entropy change (∆S) of -7.9 J/kg/K (0–2 T) was achieved.

scholarly journals Experimental investigations for a postweld heat treatment on Ti-6Al-4V titanium welds with a defocused laser beam

2020 ◽  
Vol 321 ◽  
pp. 11034
Author(s):  
J.D. Beguin ◽  
Y. Balcaen ◽  
J. Alexis ◽  
E. Andrieu
Keyword(s):  
Heat Treatment ◽  
Energy Density ◽  
Laser Beam ◽  
Local Heating ◽  
Minimum Energy ◽  
Pure Titanium ◽  
Postweld Heat Treatment ◽  
Experimental Investigations ◽  
Commercially Pure Titanium ◽  
Wide Range

The purpose of this study is to apply a local heat treatment (LHT), in-situ, on the weld bead, using a defocused Yb: YAG laser beam on a continuous regime, in order to reduce residual stresses and decompose the brittle a’ martensite, into a lamellae and fine β phase. Laser scan experiments were firstly performed on a commercially pure titanium grade 2, with a wide range of parameters, in order to provide a “heat treatment window” without titanium melting. After optimization of the processing parameters, to obtain a sufficient width and depth for the scanning zone, experiments have been performed on a β-treated, fully martensitic Ti-6Al-4V sheet. For each processing experiments, the decomposition of a’, was studied based on metallographic cross sections. A local heating with a minimum energy density at 700 J.cm-2, has a sufficient effect to destabilize a’, while for an energy density at 1000 J.cm-2 , a diffusional transformation take place, with the formation of Widmanstätten microstructure. Finally, these optimized conditions were applied on a full penetration Ti-6Al-4V welds. The results of the LHT will be described in terms of the microstructural changes observed in the welded zone and hardness evolution.

Laser beam melting and heat-treatment of 1.2343 (AISI H11) tool steel – microstructure and mechanical properties

2019 ◽  
Vol 742 ◽  
pp. 109-115 ◽  
Author(s):  
Florian Huber ◽  
Corinna Bischof ◽  
Oliver Hentschel ◽  
Johannes Heberle ◽  
Julian Zettl ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Laser Beam ◽  
Tool Steel ◽  
Steel Microstructure ◽  
Microstructure And Mechanical Properties ◽  
Laser Beam Melting

The Effect of Plastic Deformation on Magnetic and Magnetocaloric Properties of Gd90Ga10 Alloy

2016 ◽  
Vol 845 ◽  
pp. 56-60 ◽  
Author(s):  
Sergey Taskaev ◽  
Konstantin Skokov ◽  
Dmitriy Karpenkov ◽  
Vladimir V. Khovaylo ◽  
Maxim N. Ulyanov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Magnetocaloric Effect ◽  
Entropy Change ◽  
High Temperature Heat Treatment ◽  
Magnetocaloric Properties ◽  
Temperature Heat ◽  
Cold Rolled ◽  
Temperature Heat Treatment

In this work we report the results of experimental investigation of the magnetocaloric effect in Gd90Ga10 cold rolled ribbons. A moderate entropy change ΔS = 3.5 J/(kg·K) and magnetocaloric effect ΔT = 3.4K was observed for the as-cast materials in an external magnetic field of 2T which is less by 35% in comparison with the pure gadolinium metal. It was found that a significant (up to 70%) depression of magnetization and magnetocaloric properties developed in the course of plastic deformation can be completely restored by means of a high temperature heat treatment.

Surface Alloying of Iron Alloys by Laser Beam Melting

1981 ◽  
Vol 8 ◽  
Author(s):  
Barry L. Mordike ◽  
Hans W. Bergmann
Keyword(s):  
Heat Treatment ◽  
Laser Beam ◽  
Epitaxial Growth ◽  
High Power ◽  
Iron Alloys ◽  
Surface Heat ◽  
Laser Hardening ◽  
Surface Alloying ◽  
High Power Lasers ◽  
Laser Beam Melting

ABSTRACTThe surface heat treatment of iron alloys using high power lasers is reported. The essential features e.g. epitaxial growth, homogeneity etc. are discussed. The results are tabulated for the technically important alloys. The possibilities of laser hardening are demonstrated by four examples.

Effect of a Complex Heat Treatment on the Structure of 300M Steel

1981 ◽  
Vol 39 ◽  
pp. 312-313
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Metal Carbides ◽  
Austenite Grain Size ◽  
300M Steel ◽  
Heat Treated ◽  
Strain Fracture ◽  
Prior Austenite Grain Size ◽  
Short Time ◽  
Final Tempering ◽  
Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

Effect of filler wire and post weld heat treatment on the mechanical properties of laser beam-welded AA2198

2021 ◽  
pp. 111257
Author(s):  
Theano N. Examilioti ◽  
Nikolai Kashaev ◽  
Volker Ventzke ◽  
Benjamin Klusemann ◽  
Nikolaos D. Alexopoulos
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Laser Beam ◽  
Post Weld Heat Treatment ◽  
Filler Wire ◽  
Weld Heat

scholarly journals Analysis of the Welding Type and Filler Metal Influence on Performance of a Regenerated Gear

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1496
Author(s):  
Svetislav Marković ◽  
Dušan Arsić ◽  
Ružica R. Nikolić ◽  
Vukić Lazić ◽  
Nada Ratković ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Service Life ◽  
Economic Analysis ◽  
Filler Metal ◽  
Performance Characteristics ◽  
Experimental Investigations ◽  
Spur Gears ◽  
Soft Filler ◽  
Welding Procedure

This paper presents the results of voluminous experimental investigations conducted to analyze the influence of the welding procedure on the performance of regenerated gears. Cylindrical spur gears were tested, both newly manufactured and regenerated, in two fundamentally different ways: by hard facing (surfacing) with the “hard” filler metal (DUR 600-IG) and with the “soft” filler metal (EVB2CrMo) with subsequent cementation and quenching. The regeneration procedures were defined and executed, while, subsequently, the microstructure and microhardness of the hard-faced layers were established and measured, followed by checking the durability of the hard-faced teeth flanks. Finally, techno-economic analysis was performed to establish the rationality of the conducted regenerations, i.e., the costs of regenerated and newly manufactured teeth were compared. Based on the results of the conducted investigations, it was possible to establish the influence of the welding type on the performance characteristics (primarily the service life) of the regenerated gears. For individual reparatory hard facing, the procedure with the “hard” filler metal exhibited better characteristics, while for batch reparation of numerous damaged gears, the reparation with the “soft” filler metal, followed by cementation and heat treatment, might be more convenient.

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