Surface Hardening Treatment in Use of CO Gas and Post-Heat Treatment in C.P. Titanium and Titanium Alloys

2006 ◽  
Vol 118 ◽  
pp. 109-114 ◽  
Author(s):  
Y.Z. Kim ◽  
T. Murakami ◽  
Takayuki Narushima ◽  
Yasutaka Iguchi ◽  
Chiaki Ouchi
Keyword(s):  
Heat Treatment ◽  
Titanium Alloys ◽  
Layer Thickness ◽  
Surface Hardening ◽  
Surface Hardness ◽  
Type Alloy ◽  
Post Heat Treatment ◽  
Maximum Surface ◽  
Hardening Treatment ◽  
Co Gas

Surface hardening treatment of titanium materials in use of CO gas was studied including investigation of post heat treatment under vacuum. C.P. titanium, α+β type SP-700 alloy with Ti-4.5%Al-3%V-2%Mo-2%Fe and β type alloy with Ti-15%Mo-5%Zr-3%Al were used. Surface hardening was conducted by heating these materials at 1073K for 21.6ks in Ar-5%CO gas. Subsequently, specimens subjected to surface hardening were heated at 1073k for various time periods under vacuum. While the maximum surface hardness value was the largest in C.P. titanium and the least in SP-700 alloy, hardening layer thickness was the thickest in β type alloy and the thinnest in C.P. titanium. Surface hardening in C.P. titanium was brought about by solid solution hardening due to oxygen and carbon. Enrichment of these elements in the surface layer of both titanium alloys caused continuous variations of the microstructure such as β to α+β, or their volume fractions in the surface hardening layer. Post heat treatment at 1073K increased the maximum surface hardness and hardening layer thickness with an extension of the heating time in C.P. titanium, but the surface maximum hardness decreased continuously in β type titanium alloy. Post heat treatment could remove the thin oxide layer formed by surface hardening treatment.

scholarly journals Surface Hardening Treatment for Titanium Materials Using Ar-5%CO Gas in Combination with Post Heat Treatment under Vacuum

2009 ◽  
Vol 50 (12) ◽  
pp. 2763-2771 ◽  
Author(s):  
Y. Z. Kim ◽  
Takashi Konno ◽  
Taichi Murakami ◽  
Takayuki Narushima ◽  
Chiaki Ouchi
Keyword(s):  
Heat Treatment ◽  
Surface Hardening ◽  
Post Heat Treatment ◽  
Hardening Treatment ◽  
Co Gas

scholarly journals Surface Hardening Method for Titanium Materials Using Ar-5%CO Gas in Combination with Post Heat Treatment under Vacuum

2008 ◽  
Vol 72 (12) ◽  
pp. 1002-1009 ◽  
Author(s):  
Y. Z. Kim ◽  
Takashi Konno ◽  
Taichi Murakami ◽  
Takayuki Narushima ◽  
Chiaki Ouchi
Keyword(s):  
Heat Treatment ◽  
Surface Hardening ◽  
Post Heat Treatment ◽  
Co Gas

scholarly journals Surface Hardening Treatment for C.P. Titanium and Titanium Alloys in Use of Ar–5%CO Gas

2006 ◽  
Vol 46 (9) ◽  
pp. 1329-1338 ◽  
Author(s):  
Y. Z. Kim ◽  
T. Murakami ◽  
T. Narushima ◽  
Y. Iguchi ◽  
C. Ouchi
Keyword(s):  
Titanium Alloys ◽  
Surface Hardening ◽  
Hardening Treatment ◽  
Co Gas

scholarly journals The Influence of Post-Heat-Treatments on the Tensile Strength and Surface Hardness of Selective Laser Melted AlSi10Mg

2017 ◽  
Vol 370 ◽  
pp. 171-176 ◽  
Author(s):  
Leonhard Hitzler ◽  
Amandine Charles ◽  
Andreas Öchsner
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Precipitation Hardening ◽  
Elevated Temperatures ◽  
Surface Hardness ◽  
Heat Treatments ◽  
Age Hardening ◽  
Material Strength ◽  
Post Heat Treatment ◽  
Treatment Procedure

Recent investigations revealed major fluctuations in the material properties of selective laser melted AlSi10Mg, which corresponded with the varying precipitation-hardening state of the microstructure, caused by the differing dwell times at elevated temperatures. It was indicated that a subsequent heat treatment balances the age-hardening and results in a homogenized material strength. In order to further investigate this statement selective laser melted AlSi10Mg samples were subject to multiple post-heat-treatments. Subsequently, the surface hardness and tensile strength was determined and compared with the as-built results. The post-heat-treatment led to an arbitrary occurrence of rupture, indicating a successful homogenization, coupled with a remarkable improvement in ductility, but to the costs of a lowered tensile strength, which was highly dependent on the chosen heat-treatment procedure.

scholarly journals Surface Hardening Treatment for Titanium and Titanium Alloys in Use of CO2 Gas

2006 ◽  
Vol 92 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Y.-Z. KIM ◽  
Ryoji SAHARA ◽  
Takayuki NARUSHIMA ◽  
Yasutaka IGUCHI ◽  
Chiaki OUCHI
Keyword(s):  
Titanium Alloys ◽  
Surface Hardening ◽  
Hardening Treatment

scholarly journals The mathematical modeling of the process of hardening treatment of titanium blades of steam turbines

2021 ◽  
Vol 344 ◽  
pp. 01006
Author(s):  
Alexander Filonovich ◽  
Irina Vornacheva ◽  
Artem Chuichenko ◽  
Evgeny Bolotnikov
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Models ◽  
Titanium Alloys ◽  
Surface Hardening ◽  
Electrospark Alloying ◽  
Steam Turbines ◽  
Technological Processes ◽  
Hardening Treatment

Mathematical models of the surface hardening of VT20 and OT4 titanium alloys by electrospark alloying have been developed. These models can be used in the design of technological processes for the manufacture of titanium blades for steam turbines.

scholarly journals Comparison of Wear Performance of Austempered and Quench-Tempered Gray Cast Irons Enhanced by Laser Hardening Treatment

2020 ◽  
Vol 10 (9) ◽  
pp. 3049
Author(s):  
Bingxu Wang ◽  
Gary C. Barber ◽  
Rui Wang ◽  
Yuming Pan
Keyword(s):  
Heat Treatment ◽  
Cast Iron ◽  
Surface Hardening ◽  
Gray Cast Iron ◽  
High Hardness ◽  
Laser Surface ◽  
Gray Cast ◽  
Wear Loss ◽  
Laser Surface Hardening ◽  
Hardening Treatment

The current research studied the effects of laser surface hardening treatment on the phase transformation and wear properties of gray cast irons heat treated by austempering or quench-tempering, respectively. Three austempering temperatures of 232 °C, 288 °C, and 343 °C with a constant holding duration of 120 min and three tempering temperatures of 316 °C, 399 °C, and 482 °C with a constant holding duration of 60 min were utilized to prepare austempered and quench-tempered gray cast iron specimens with equivalent macro-hardness values. A ball-on-flat reciprocating wear test configuration was used to investigate the wear resistance of austempered and quench-tempered gray cast iron specimens before and after applying laser surface-hardening treatment. The phase transformation, hardness, mass loss, and worn surfaces were evaluated. There were four zones in the matrix of the laser-hardened austempered gray cast iron. Zone 1 contained ledeburite without the presence of graphite flakes. Zone 2 contained martensite and had a high hardness, which was greater than 67 HRC. Zone 4 was the substrate containing the acicular ferrite and carbon-saturated austenite with a hardness of 41–27 HRC. In Zone 3, the substrate was tempered by the low thermal radiation. For the laser-hardened quench-tempered gray cast iron specimens, three zones were observed beneath the laser-hardened surface. Zone 1 also contained ledeburite, and Zone 2 was full martensite. Zone 3 was the substrate containing the tempered martensite. The tempered martensite became coarse with increasing tempering temperature due to the decomposition of the as-quenched martensite and precipitation of cementite particles. In the wear tests, the gray cast iron specimens without heat treatment had the highest wear loss. The wear performance was improved by applying quench-tempering heat treatment and further enhanced by applying austempering heat treatment. Austempered gray cast iron specimens had lower mass loss than the quench-tempered gray cast iron specimens, which was attributed to the high fracture toughness of acicular ferrite and stable austenite. After utilizing the laser surface hardening treatment, both austempered and quench-tempered gray cast iron specimens had decreased wear loss due to the high surface protection provided by the ledeburitic and martensitic structures with high hardness. In the worn surfaces, it was found that cracks were the dominant wear mechanism. The results of this work have significant value in the future applications of gray cast iron engineering components and provide valuable references for future studies on laser-hardened gray cast iron.

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