Microstructural characteristics and high-temperature oxidation resistance of a double-glow plasma-chromized surface layer on TiAl intermetallics

2019 ◽  
Vol 6 (12) ◽  
pp. 1265a9
Author(s):  
Dongsheng Wang ◽  
Xinghua Zhou
Keyword(s):  
Surface Layer ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Microstructural Characteristics ◽  
Temperature Oxidation ◽  
Tial Intermetallics ◽  
Glow Plasma

Research on high-temperature oxidation resistance, hot forming ability, and microstructure of Al–Si–Cu coating for 22MnB5 steel

2021 ◽  
Vol 40 (1) ◽  
pp. 397-409
Author(s):  
Ziliu Xiong ◽  
Zhangguo Lin ◽  
Jianjun Qi ◽  
Li Sun ◽  
Guangxin Wu ◽  
...  
Keyword(s):  
Surface Layer ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Hot Stamping ◽  
Optical Microscope ◽  
Hot Forming ◽  
Metal Compound ◽  
Temperature Oxidation ◽  
Substrate Steel

Abstract High-temperature oxidation resistance, hot formability, element distribution, and microstructure of Al-10% Si-(0.5–3.0%)Cu coating were investigated by means of glow discharge spectroscopy, optical microscope, scanning electron microscope, and energy-dispersive spectroscopy. Results show that the addition of Cu can increase high-temperature oxidation resistance above 950°C and improve hot formability so that no crack spreads into substrate steel as hot forming at 33.3% strain. Oxidation film structure is continual and compacting, and Si highly concentrates in the surface layer. The distribution of Cu has skin effect with peaking content 8.2% in the surface layer. After hot stamping, Al and Si diffuse into substrate steel, and Cu diffuses from inner to outer coating. Al–Si–Cu coating has smoother surface, straighter diffusion layer, and finer metal compound than Al–Si coating. Surface and diffusion layers are identified as aluminum oxide, Si-rich, and Cu phase and Al7SiFe2, Al3Fe, and CuAl3, respectively. Al-rich phase and the metal compound are composed of α-Al dissolving Fe, Si, and Cu and Al–Si matrix, Cu3Al, respectively.

Microstructure Characteristics and High-Temperature Oxidation Behavior of Plasma-Sprayed and Laser-Remelted MCrAlY Coatings on TiAl Intermetallics

2011 ◽  
Author(s):  
Zongjun Tian ◽  
Lida Shen ◽  
Zhidong Liu ◽  
Yinhui Huang
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Plasma Spraying ◽  
High Temperature Oxidation ◽  
Intermetallic Alloys ◽  
Laser Remelting ◽  
Temperature Oxidation ◽  
Mcraly Coatings ◽  
Tial Intermetallics ◽  
Plasma Sprayed

In order to further improve the high-temperature oxidation resistance of TiAl intermetallic alloys, MCrAlY coatings were fabricated by plasma spraying and plasma spraying-laser remelting technologies. The microstructures of the as-sprayed and laser-remelted MCrAlY coatings were studied. In addition, the oxidation behaviors at 850 °C for three samples were investigated. One sample is the matrix of TiA1 intermetallic alloys, the other one is processed by plasma-spraying MCrAlY coatings, and the third one is processed by plasma-spraying and laser-remelting MCrAlY coatings. It was revealed that the oxidation resistance of TiAl intermetallics is weak due to lack of protection of Al2O3 film formed on the surface. The plasma-sprayed MCrAlY coatings have better oxidation resistance than the TiAl intermetallics although the plasma-sprayed MCrAlY coatings have high density of porosity and a typical layered structure. It is demonstrated that most of the holes can be eliminated by laser remelting, leading to the best oxidation resistance of the third sample with the laser-remelted coatings. The high oxidation resistance of the laser-remelted coatings is mainly attributed to three aspects: firstly, an Al enriched zone on the coating surface is formed during laser remelting, which is transformed into a protective Al2O3 film during oxidation process. Secondly, laser remelting eliminates most of the defects in plasma-sprayed coatings and enhances its density, thus decreases the channel of oxidation diffusion in high temperature oxidation process. Thirdly, rapid cooling of laser remelting results in a grain refinement and a preferred oxidation of Al at the initial stage, leading to a reduction of oxidation rate.

Research on Microstructure and Oxidation Resistance of Double Glow Plasma Discharge Surface Titanizing on CrZrCu Alloy

2010 ◽  
Vol 152-153 ◽  
pp. 1079-1082
Author(s):  
Fang Tu ◽  
Bo Lin He
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Spot Welding ◽  
High Temperature Oxidation ◽  
Steel Sheet ◽  
Plasma Discharge ◽  
Experimental Results ◽  
Galvanized Steel ◽  
Temperature Oxidation ◽  
Glow Plasma

CrZrCu is extensively used as high electrical, thermal and mechanical performance in spot welding. But when CrZrCu electrode is used in spot welding of galvanized steel sheet, the abrasion, corrosion and oxidation shorten the electrode life rapidly. The electrode is not able to meet the needs of spot welding of galvanized steel sheet .In the paper, double glow plasma discharge surface titanizing was carried out on CrZrCu alloy. The processes of double glow plasma discharge titanizing, surface alloying layer structure were also analyzed elementary. The properties of high temperature oxidation were also researched. The experimental results indicated that in the plasma titanizing alloying layer, the diffusion of titanium element toward the interior of the CrZrCu alloy substrate forms the intermetallic compound named Cu4Ti, which is beneficial to the reinforcement of CrZrCu substrate. The experimental results confirmed that double glow plasma discharge titanizing could greatly improve the high temperature oxidation resistance of CrZrCu alloy. Under the temperature of 450oC and 700oC, the oxidation rate of CrZrCu is about five times of plasma titanzing sample.

scholarly journals Isothermal Oxidation Behavior of Zr-Y Coating on γ-TiAl by Double Glow Plasma Surface Metal Alloying Technique

Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 361 ◽  
Author(s):  
Feng Ding ◽  
Pingze Zhang ◽  
Dongbo Wei ◽  
Xiaohu Chen ◽  
Shiyuan Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Kinetic ◽  
Isothermal Oxidation ◽  
Temperature Oxidation ◽  
Plasma Surface ◽  
Surface Metal ◽  
Glow Plasma ◽  
Plasma Surface Alloying Technique

Oxidation resistance of Zr-Y coating on γ-TiAl alloy prepared by a double-glow plasma surface alloying technique was investigated in static air at 750 °C, 800 °C and 850 °C for 100 h. A pure Zr coating was also prepared for comparison. Addition of Y improved high-temperature oxidation resistance of the alloying coating because of its refining effect and inhibition of cationic diffusion. Oxidation kinetic curves indicated that the high-temperature oxidation resistance of the Zr-Y coating was about eight times higher than that of the bare substrate and about 3 times higher than that of pure Zr coating.

AK STEEL 441

Alloy Digest ◽  
2006 ◽  
Vol 55 (6) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
Ferritic Stainless Steel ◽  
High Temperature Oxidation ◽  
High Temperature Strength ◽  
Temperature Oxidation ◽  
Temperature Performance

Abstract AK Steel 441 has good high-temperature strength, an equiaxed microstructure, and good high-temperature oxidation resistance. The alloy is a niobium-bearing ferritic stainless steel. This datasheet provides information on composition, hardness, and tensile properties as well as deformation. It also includes information on high temperature performance and corrosion resistance as well as forming and joining. Filing Code: SS-965. Producer or source: AK Steel.

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