Rapidly Solidified Thick Deposit of Fe-B-Cr Alloy by Plasma Spraying

2007 ◽  
Vol 561-565 ◽  
pp. 721-724 ◽  
Author(s):  
Yasuhiro Hoshiyama ◽  
Kentaro Hirano ◽  
Hidekazu Miyake ◽  
Kenji Murakami
Keyword(s):  
Heat Treatment ◽  
Amorphous Phase ◽  
Alloy Powder ◽  
Α Phase ◽  
Heat Treated ◽  
Low Pressure Plasma ◽  
Base Composite ◽  
Plasma Sprayed ◽  
Rapidly Solidified ◽  
Thick Deposit

Fe-B-Cr alloy powder in diameter of 32-53 μm made by argon atomization is low-pressure plasma sprayed to produce a rapidly solidified iron base composite deposit with finely dispersed boride particles. The constituents of the as-sprayed deposit formed on a water-cooled substrate are α phase and amorphous phase that are supersaturated with chromium and boron due to high cooling rate during solidification of the melt. Heat treatment of deposit at 873K leads to decomposition of the amorphous phase, resulting in the formation of Fe3B. The deposit heat treated above 1073K is composed of α phase and (Fe,Cr)2B. The as-sprayed deposit produced on a non-cooled substrate consists of α phase and (Fe,Cr)2B. The fine precipitates of about 0.1 μm in the as-sprayed deposit coated on a non-cooled substrate are boride. As deposit temperature increases, the coarsening of the precipitate particles results in lowered hardness of deposits.

Tungsten Carbide Dispersed High Cr-Ni Cast Iron Produced by Plasma Spraying

2017 ◽  
Vol 891 ◽  
pp. 565-568
Author(s):  
Yasuhiro Hoshiyama ◽  
Kyouhei Yamaguchi ◽  
Hidekazu Miyake
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Tungsten Carbide ◽  
Alloy Powder ◽  
Treatment Temperature ◽  
Heat Treated ◽  
Ni Alloy ◽  
Low Pressure Plasma ◽  
Plasma Sprayed ◽  
Carbide Particles

Fe-C-W-Cr-Ni alloy powder in diameter of 32-53 μm made by argon atomization was low-pressure plasma sprayed to produce high Cr-Ni cast iron base deposits with finely dispersed tungsten carbide particles. The as-sprayed deposit produced on a non-cooled substrate was composed of γFe, αFe and carbide. The fine precipitates in the as-sprayed deposit were carbide. With increasing heat treatment temperature up to 1273 K, the carbide particles coarsened. The as-sprayed deposit produced on a non-cooled substrate had higher hardness than the heat-treated deposits. The wear resistance of the as-sprayed deposit produced on a non-cooled substrate was lower than that of heat-treated deposits. The as-sprayed deposit produced on a non-cooled substrate and heat-treated deposits had higher wear resistance than commercial stainless steel.

scholarly journals Enhancing Graphene Retention and Electrical Conductivity of Plasma-Sprayed Alumina/Graphene Nanoplatelets Coating by Powder Heat Treatment

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 643
Author(s):  
Xiaoyu Wu ◽  
Shufeng Xie ◽  
Kangwei Xu ◽  
Lei Huang ◽  
Daling Wei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Structural Integrity ◽  
Ceramic Coatings ◽  
Treatment Temperature ◽  
Graphene Nanoplatelets ◽  
Structural Defects ◽  
Temperature Plasma ◽  
Heat Treated ◽  
Plasma Sprayed

Burning loss of graphene in the high-temperature plasma-spraying process is a critical issue, significantly limiting the remarkable performance improvement in graphene reinforced ceramic coatings. Here, we reported an effective approach to enhance the graphene retention, and thus improve the performance of plasma-sprayed alumina/graphene nanoplatelets (Al2O3/GNPs) coatings by heat treatment of agglomerated Al2O3/GNPs powders. The effect of powder heat treatment on the microstructure, GNPs retention, and electrical conductivity of Al2O3/GNPs coatings were systematically investigated. The results indicated that, with the increase in the powder heat treatment temperature, the plasma-sprayed Al2O3/GNPs coatings exhibited decreased porosity and improved adhesive strength. Thermogravimetric analysis and Raman spectra results indicated that increased GNPs retention from 12.9% to 28.4%, and further to 37.4%, as well as decreased structural defects, were obtained for the AG, AG850, and AG1280 coatings, respectively, which were fabricated by using AG powders without heat treatment, powders heat-treated at 850 °C, and powders heat-treated at 1280 °C. Moreover, the electrical conductivities of AG, AG850, and AG1280 coatings exhibited 3 orders, 4 orders, and 7 orders of magnitude higher than that of Al2O3 coating, respectively. Powder heat treatment is considered to increase the melting degree of agglomerated alumina particles, eventually leaving less thermal energy for GNPs to burn; thus, a high retention amount and structural integrity of GNPs and significantly enhanced electrical conductivity were achieved for the plasma-sprayed Al2O3/GNPs coatings.

scholarly journals Effect of Heat Treatment Temperature on Martensitic Transformation and Superelasticity of the Ti49Ni51 Shape Memory Alloy

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2539 ◽  
Author(s):  
Peiyou Li ◽  
Yongshan Wang ◽  
Fanying Meng ◽  
Le Cao ◽  
Zhirong He
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Thermal Hysteresis ◽  
Treatment Temperature ◽  
Heat Treated ◽  
Different Temperatures ◽  
Tini Phase ◽  
Rapidly Solidified

The martensitic transformation and superelasticity of Ti49Ni51 shape memory alloy heat-treatment at different temperatures were investigated. The experimental results show that the microstructures of as-cast and heat-treated (723 K) Ni-rich Ti49Ni51 samples prepared by rapidly-solidified technology are composed of B2 TiNi phase, and Ti3Ni4 and Ti2Ni phases; the microstructures of heat-treated Ti49Ni51 samples at 773 and 823 K are composed of B2 TiNi phase, and of B2 TiNi and Ti2Ni phases, respectively. The martensitic transformation of as-cast Ti49Ni51 alloy is three-stage, A→R→M1 and R→M2 transformation during cooling, and two-stage, M→R→A transformation during heating. The transformations of the heat-treated Ti49Ni51 samples at 723 and 823 K are the A↔R↔M/A↔M transformation during cooling/heating, respectively. For the heat-treated alloy at 773 K, the transformations are the A→R/M→R→A during cooling/heating, respectively. For the heat-treated alloy at 773 K, only a small thermal hysteresis is suitable for sensor devices. The stable σmax values of 723 and 773 K heat-treated samples with a large Wd value exhibit high safety in application. The 773 and 823 K heat-treated samples have large stable strain–energy densities, and are a good superelastic alloy. The experimental data obtained provide a valuable reference for the industrial application of rapidly-solidified casting and heat-treated Ti49Ni51 alloy.

High Cr-Ni Cast Iron Base Deposits with Tantalum Carbide Particles Produced by Plasma Spraying

2014 ◽  
Vol 782 ◽  
pp. 563-566
Author(s):  
Yasuhiro Hoshiyama ◽  
Toshiaki Otani ◽  
Hidekazu Miyake
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Tantalum Carbide ◽  
Iron Base ◽  
Heat Treated ◽  
Plasma Sprayed ◽  
Carbide Particles

Fe-C-Ta-Cr-Ni alloy powder in diameter of 32-53 μm made by argon atomization was low-pressure plasma sprayed to produce high Cr-Ni cast iron base deposits with finely dispersed tantalum carbide particles. The as-sprayed deposit formed on a water-cooled substrate consisted of γFe, αFe and carbide. The fine precipitates of approximately 0.1 μm in the as-sprayed deposit formed on a water-cooled substrate were carbide. With increasing heat treatment temperature up to 1273 K, the carbide particles coarsened. The hardness of deposit decreases with increasing heat treatment temperature. The wear resistance of as-sprayed deposit formed on a non-cooled substrate was higher than that of the deposit heat-treated at 1273 K. The as-sprayed deposit and deposit heat-treated at 1273 K hade higher wear resistance than a commercial stainless steel.

Neutron Diffraction Residual Strain Measurements in Plasma Sprayed Nanostructured Hydroxyapatite Coatings for Orthopaedic Implants

2010 ◽  
Vol 652 ◽  
pp. 309-314 ◽  
Author(s):  
Rehan Ahmed ◽  
Nadimul Haque Faisal ◽  
Stefan M. Knupfer ◽  
Anna Maria Paradowska ◽  
Michael E. Fitzpatrick ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Neutron Diffraction ◽  
Residual Strain ◽  
Strain Measurements ◽  
Strain Profile ◽  
Hydroxyapatite Coatings ◽  
Heat Treated ◽  
Residual Strains ◽  
Biomedical Coatings ◽  
Plasma Sprayed

Residual strains in plasma sprayed and heat-treated hydroxyapatite (HA) coatings deposited on a titanium alloy (Ti-6Al-4V) substrate were investigated by means of neutron diffraction. Strain measurements were performed in vertical scan (“z-scanning”) mode to provide a through thickness strain profile in the coating and substrate materials. Results are discussed in terms of the influence of heat-treatment on the residual strain profile of these biomedical coatings. This investigation concluded that the heat-treatment had a significant effect on the residual strain profile in HA coatings.

scholarly journals The Effects of Post Heat Treatment on the Microstructural and Mechanical Properties of an Additive-Manufactured Porous Titanium Alloy

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 593 ◽  
Author(s):  
Guisheng Yu ◽  
Zhibin Li ◽  
Youlu Hua ◽  
Hui Liu ◽  
Xueyang Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Energy Absorption ◽  
Porous Titanium ◽  
Absorption Efficiency ◽  
Treatment Temperature ◽  
Post Heat Treatment ◽  
Α Phase ◽  
Heat Treated ◽  
Energy Absorption Efficiency

In this work, Ti-6Al-4V (Ti64) porous structures were prepared by selective laser melting (SLM), and the effects of post heat treatment on its microstructural and mechanical properties were investigated. The results showed that as SLM samples were mainly composed of needle-like α′ martensite. Heat treatment at 750 °C caused α′ phase to decompose, forming a lamellar α+β mixed microstructure. As the heat treatment temperature increased to 950 °C, the width of lamellar α phase gradually increased to 3.1 μm. Heat treatment also reduced the compressive strength of the samples; however, it significantly improved the ductility of the porous Ti64. Moreover, heat treatment improved the energy absorption efficiency of the porous Ti64. The samples heat-treated at 750 °C had the highest energy absorption of 233.6 ± 1.5 MJ/m3 at ε = 50%.

scholarly journals The Microstructural Difference and Its Influence on the Ballistic Impact Behavior of a Near β-Type Ti5.1Al2.5Cr0.5Fe4.5Mo1.1Sn1.8Zr2.9Zn Titanium Alloy

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4006 ◽  
Author(s):  
Xinjie Zhu ◽  
Qunbo Fan ◽  
Duoduo Wang ◽  
Haichao Gong ◽  
Hong Yu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Dislocation Density ◽  
Titanium Alloys ◽  
Impact Behavior ◽  
Alloy Plate ◽  
Α Phase ◽  
Heat Treated ◽  
Hot Rolled ◽  
Titanium Alloy Plate

In this work, a near β-type Ti5.1Al2.5Cr0.5Fe4.5Mo1.1Sn1.8Zr2.9Zn alloy was hot-rolled at the temperature of 800–880 °C with a thickness reduction of 87.5% and then heat-treated with the strategy of 880 °C/1 h/air cooling (AC) + 650 °C/3 h/AC. The microstructure difference between the hot-rolled and heat-treated titanium alloys and its influence on the ballistic impact behavior of the hot-rolled and heat-treated titanium alloys were analyzed. The microstructural investigation revealed that the average size of the acicular secondary α phase (αs) dropped from 75 to 42 nm, and the corresponding amount of this phase increased significantly after heat treatment. In addition, the dislocation density of the α and β phases decreased from 0.3340 × 1015/m2 and 4.6746 × 1015/m2 for the hot-rolled titanium alloy plate to 0.2806 × 1015/m2 and 1.8050 × 1015/m2 for the heat-treated one, respectively. The high strength of the heat-treated titanium alloy was maintained, owing to the positive contribution of the acicular secondary α phase. Furthermore, the critical fracture strain increased sharply from 19.9% for the hot-rolled titanium alloy plate to 23.1% for the heat-treated one, thereby overcoming (to some extent) the constraint of the strength–ductility trade-off. This is mainly attributed to the fact that the dislocation density and the difference between the dislocation densities of the α and β phases decreased substantially, and deformation localization was effectively suppressed after heat treatment. Damage to the hot-rolled and heat-treated titanium alloy plates after the penetration of a 7.62 mm ordinary steel core projectile at a distance of 100 m was assessed via industrial computer tomography and microstructure observation. The results revealed that a large crack (volume: 2.55 mm3) occurred on the rear face and propagated toward the interior of the hot-rolled titanium alloy plate. The crack tip was connected to a long adiabatic shear band with a depth of 3 mm along the thickness direction. However, good integrity of the heat-treated titanium alloy plate was maintained, owing to its excellent deformation capability. Ultimately, the failure mechanism of the hot-rolled and heat-treated titanium alloy plates was revealed by determining the crack-forming reasons in these materials.

Effects on Microstructure and Corrosion Behavior of a Heat Treated CuZn36Pb2 Brass

2020 ◽  
Vol 405 ◽  
pp. 333-338
Author(s):  
Roland Haubner ◽  
Susanne Strobl ◽  
Paul Linhardt
Keyword(s):  
Heat Treatment ◽  
Phase Diagram ◽  
Sea Water ◽  
X Ray Diffraction ◽  
Corrosion Tests ◽  
X Ray ◽  
Fine Grained ◽  
Β Phase ◽  
Α Phase ◽  
Heat Treated

The brass CuZn36Pb2 is widely used for fittings, valves and other installation materials. Failures are observed occasionally caused by corrosion. Considering the Cu-Zn phase diagram only α-phase exists in the range of 650 and 300 °C. At higher temperatures α- and β-phase is stable and at lower temperatures α- and β´-phase exist. Since the β-phase is Zn-enriches, it is attacked severely by corrosion. In the recent work brass samples were heat treated at temperatures between 850 and 200 °C to study the microstructural changes and the corresponding electrochemical properties. Potentiostatic corrosion tests were applied in artificial fresh water and sea water at different potential settings. After a heat treated at 850 °C the brass has formed b-phase which can be shown by metallography. At lower temperatures the microstructure is fine grained and no β-phase was observed. To verify the presence of β´-phase a heat treatment at 200 °C was performed but no β´-phase was observed, which was confirmed additionally by X-ray diffraction. Again, after corrosion tests the samples were investigated by metallography and the β-phase was obviously more attacked than the α-phase.

Production of Stainless Cast Iron Base Deposits with Dispersed Titanium Carbide Particles by Plasma Spraying

2010 ◽  
Vol 654-656 ◽  
pp. 1888-1891 ◽  
Author(s):  
Yasuhiro Hoshiyama ◽  
Tsutomu Miyazaki ◽  
Hidekazu Miyake
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
Titanium Carbide ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Iron Base ◽  
Heat Treated ◽  
Plasma Sprayed ◽  
Carbide Particles

Fe-C-Ti-Cr-Ni alloy powder in diameter of 32-53 μm made by argon atomization is low-pressure plasma sprayed to produce stainless cast iron base deposits with finely dispersed titanium carbide particles. The as-sprayed deposit formed on a water-cooled substrate consists of γFe, αFe, TiC and Cr3C2. Heat treatment of the as-sprayed deposit above 873 K results in the formation of Cr7C3. The fine precipitates of approximately 0.2 μm in the as-sprayed deposit formed on a water-cooled substrate are carbide. The as-sprayed deposit produced on a non-cooled substrate and deposits which are obtained by heat treatment of the as-sprayed deposit are composed of γFe, αFe, TiC, Cr3C2 and Cr7C3. As heat treatment temperature increases, carbide precipitates coarsen. The hardness of deposit decreases with increasing heat treatment temperature. The wear resistance of as-sprayed deposit formed on a non-cooled substrate was higher than that of the deposit heat-treated at 1273 K. The as-sprayed deposit and deposit heat-treated at 1273 K have higher wear resistance than a commercial stainless steel.

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