The Research on Hard Cutting the Powder Metallurgy Valve Seat

2016 ◽  
Vol 693 ◽  
pp. 1177-1181
Author(s):  
Ning Ding ◽  
Hai Dong Yang ◽  
Xiao Jun Niu ◽  
Hong Yun Chen
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Temperature Stability ◽  
High Hardness ◽  
Dimensional Accuracy ◽  
High Temperature Stability ◽  
Valve Seat ◽  
Hard Cutting

Powder metallurgy valve seat is an important part for engine; the material has excellent properties such as the wear-resistance of high temperature, corrosion proof and high temperature stability etc. But because of its high hardness, porous nature and contains many microscopic characteristics of the hard particles and the like, common tools cut these parts wear out quickly. And the valve seat requires higher dimensional accuracy and surface roughness, so these bring a lot of difficulties to cut these parts. Because of Polycrystalline Cubic Boron Nitride (hereafter referred to as PCBN) cutting tool has such advantages as high hardness; wear resistance; minimum surface roughness, so it has a great advantage on hard cutting the powder metallurgy valve seat. By hard cutting the powder metallurgy valve seat experiments, to research on the wear form and the cutting parameters impact on the cutting force.

scholarly journals Bulk high-entropy nitrides and carbonitrides

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Olivia F. Dippo ◽  
Neda Mesgarzadeh ◽  
Tyler J. Harrington ◽  
Grant D. Schrader ◽  
Kenneth S. Vecchio
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Configurational Entropy ◽  
Temperature Stability ◽  
High Hardness ◽  
Valence Electron Concentration ◽  
High Temperature Stability ◽  
High Entropy ◽  
Rule Of Mixtures ◽  
Traditional Ceramics

AbstractHigh-entropy ceramics have potential to improve the mechanical properties and high-temperature stability over traditional ceramics, and high entropy nitrides and carbonitrides (HENs and HECNs) are particularly attractive for high temperature and high hardness applications. The synthesis of 5 bulk HENs and 4 bulk HECNs forming single-phase materials is reported herein among 11 samples prepared. The hardness of HENs and HECNs increased by an average of 22% and 39%, respectively, over the rule-of-mixtures average of their monocarbide and mononitride precursors. Similarly, elastic modulus values increased by an average of 17% in nitrides and 31% in carbonitrides over their rule-of-mixtures values. The enhancement in mechanical properties is tied to an increase in the configurational entropy and a decrease in the valence electron concentration, providing parameters for tuning mechanical properties of high-entropy ceramics.

The Influence of Degree of Polymerization on Precursor-Derived Si-B-C-N Ceramics

2010 ◽  
Vol 650 ◽  
pp. 355-360
Author(s):  
Xiang Geng ◽  
X. Huang ◽  
Ya Jing Li ◽  
Song Li ◽  
Xiao Bin Shi
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Amorphous Materials ◽  
Chemical Properties ◽  
Temperature Stability ◽  
High Hardness ◽  
Nitrogen Atmosphere ◽  
Degree Of Polymerization ◽  
Pyrolysis Process ◽  
High Temperature Stability

Precursor derived Si-B-C-N ceramic is a kind of amorphous materials with high hardness, low density, durability at extremely high temperature. The materials show a great potential to be used in the field of the Thermal Protective System (TPS). The physical states and chemical properties of the amorphous materials greatly depend on the starting materials. The effect of degree of polymerization (DP) of the precursor on the pyrolysis process and the characteristics of the amorphous Si-B-C-N materials are studied. The SiBCN-based preceramic polymer synthesized by dichloromethylvinylsilane, ammonia and BH3•SMe2. Dichloromethylvinylsilane reacted with ammonia and BH3•SMe2 in toluene or tetrahydrofuran (THF) as solvent in the presence of catalytic amounts of pyridine. The polymeric precursors were cured at low temperature to obtain solid-state precursors. Pyrolysis process of the solid-state precursors under various temperatures and carried out in nitrogen atmosphere. The results showed that DP of the precursor influences the pyrolysis process and the high temperature stability of the Si-B-C-N amorphous ceramics.

Wear Mechanism of PCBN Hard Cutting the Powder Metallurgy Valve Seats

2016 ◽  
Vol 693 ◽  
pp. 996-1002
Author(s):  
Hai Dong Yang ◽  
Ning Ding ◽  
Xiao Jun Niu ◽  
Hong Yun Chen ◽  
Zheng Ye
Keyword(s):  
Powder Metallurgy ◽  
Wear Mechanism ◽  
Cubic Boron Nitride ◽  
High Hardness ◽  
Valve Seat ◽  
Dry Cutting ◽  
Hard Particles ◽  
Diffusion Wear ◽  
Oxidation Wear ◽  
Hard Cutting

Polycrystalline Cubic Boron Nitride (PCBN) tool is suitable for cutting powder metallurgy valve seat, which has high hardness and contains hard particles. By hard dry cutting different materials of powder metallurgy valve seat, the results show that: tool life when cutting melting copper powder metallurgy valve seat is longer; breakage failure is the main failure forms of tool and wear mechanism contains hard spots scratches, adhesive wear, diffusion wear and oxidation wear.

REYNOLDS 390 and A390

Alloy Digest ◽  
1971 ◽  
Vol 20 (8) ◽  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
High Hardness ◽  
Heat Treating ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Temperature Performance

Abstract REYNOLDS 390 and A390 are hypereutectic aluminum-silicon alloys having excellent wear resistance coupled with good mechanical properties, high hardness, and low coefficients of expansion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, and machining. Filing Code: Al-203. Producer or source: Reynolds Metals Company.

UNS N06455

Alloy Digest ◽  
1989 ◽  
Vol 38 (1) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Stress Corrosion Cracking ◽  
Temperature Stability ◽  
Heat Treating ◽  
High Ductility ◽  
High Temperature Stability ◽  
Nickel Chromium ◽  
Long Time ◽  
Resistance To Stress

Abstract UNS NO6455 is a nickel-chromium-molybdenum alloy with outstanding high-temperature stability as shown by high ductility and corrosion resistance even after long-time aging in the range 1200-1900 F. The alloy also has excellent resistance to stress-corrosion cracking and to oxidizing atmospheres up to 1900 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-367. Producer or source: Nickel and nickel alloy producers.

UNS R54620

Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Time Use ◽  
Temperature Stability ◽  
High Strength ◽  
Heat Treating ◽  
High Temperature Stability ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Long Time

Abstract UNS No. R54620 is an alpha-beta titanium alloy. It has an excellent combination of tensile strength, creep strength, toughness and high-temperature stability that makes it suitable for service to 1050 F. It is recommended for use where high strength is required. It has outstanding advantages for long-time use at temperatures to 800 F. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-86. Producer or source: Titanium alloy mills.

DURATECH 30

Alloy Digest ◽  
2006 ◽  
Vol 55 (3) ◽  
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
High Hardness ◽  
Heat Treating ◽  
Powder Metal ◽  
Temperature Performance ◽  
Very High

Abstract DuraTech 30 is a superhigh-speed steel evolved from the ASTM M3-2 composition, but with added cobalt. The exotic composition offers improved toughness and very high hardness. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on high temperature performance and wear resistance as well as heat treating, machining, and powder metal forms. Filing Code: TS-629. Producer or source: Timken Latrobe Steel.

YSS HAP72

Alloy Digest ◽  
2019 ◽  
Vol 68 (10) ◽  
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Tool Steel ◽  
High Speed ◽  
High Wear Resistance ◽  
Bend Strength ◽  
Temperature Performance ◽  
Very High

Abstract YSS HAP72 is a powder metallurgy high-speed tool steel with a very high wear resistance. This datasheet provides information on composition, hardness, and bend strength. It also includes information on high temperature performance. Filing Code: TS-779. Producer or source: Hitachi Metals America Ltd.

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