Tribological Properties of SiC Whisker Containing Silicon Nitride Composite

1988 ◽  
Vol 110 (3) ◽  
pp. 434-438 ◽  
Author(s):  
H. Ishigaki ◽  
R. Nagata ◽  
M. Iwasa ◽  
N. Tamari ◽  
I. Kondo

The friction and wear characteristics of SiC whisker containing composite silicon nitride were studied. Silicon nitride powder which contains densification aids of Y2O3 and La2O3 was mixed with silicon carbide whiskers (10, 20, and 30 wt percent) and then hot-pressed at a temperature of 1800° C. Wear experiments were carried out with a ring on block type apparatus at the sliding conditions of the sliding speed of 314 mm/sec and the load of 5 N and experimental results showed that the SiC whisker had an evident effect to reduce the wear rate of silicon nitride blocks. Silicon carbide whiskers are not dispersed isotropically, but they are oriented to the direction which is perpendicular to the pressure of hot-press sintering. Therefore, wear characteristics of the composite ceramics are anisotropic. The effect of SiC whisker on wear rate of silicon nitride is larger for the surface which is perpendicular to the direction of pressure of hot-press sintering that than that for the surface which is parallel to the pressure. Although SiC whiskers have no evident effect on friction coefficient of silicon nitride at the above sliding condition, even small contents of SiC whiskers, such as 10 wt percent, reduce considerably the coefficient of friction and show similar frictional characteristics to that of monolithic silicon carbide at the lower sliding speed of 10 mm/min.

2021 ◽  
pp. 1-27
Author(s):  
Alexander Grenadyorov ◽  
Andrey Solovyev ◽  
Konstantin Oskomov

Abstract The paper presents the experimental study of the friction and wear characteristics of amorphous carbon coating containing hydrogen and SiOx (a-C:H:SiOx) deposited onto WC-8Co cemented carbide substrates. A 5 μm thick a-C:H:SiOx coating was fabricated using plasma-assisted chemical vapor deposition. The tribological properties of the a-C:H:SiOx coating sliding in contact with WC–8Co, ZrO2, SiC, Si3N4 counter bodies, are examined using the ball-on-disc method at different normal loads and sliding speeds. Tribology testing shows that the minimum values of the friction coefficient (0.044) and the wear rate (9.3×10−8 mm3/Nm) are observed when using a counter body made of silicon nitride at a 5 N indentation load. The load increase from 5 to 12 N raises the friction coefficient up to 0.083 and the wear rate up to 46×10−8 mm3/Nm. When the sliding speed reaches its critical value, the coating friction provides the transition from sp3 hybridized to sp2 hybridized and polymeric carbon, which is accompanied by the reduction in the friction coefficient. The a-C:H:SiOx coating provides an increase in the critical sliding speed up to 50–75 mm/s, which exceeds that of non-alloyed (a-C and a-C:H) diamond-like carbon coatings as a result of doping by silicon and oxygen.


Author(s):  
Raj Mohan Radhakrishnan ◽  
Venkatraman Ramamoorthi ◽  
Raghuraman Srinivasan

High strength-to-weight ratio materials are used in the automotive and aerospace industries, and AlSi10Mg is suitable for those applications. The research aims to compare and investigate the wear characteristics of selective laser melted AlSi10Mg pin against two counter bodies, EN-31 hardened steel, and silicon carbide abrasive sheet. The wear rate of additively manufactured AlSi10Mg pin at 0° building orientation was investigated using the box Behnken design approach to identify the suitable wear parameters with the pin on the disc testing facility. Based on analysis of variance, the interaction of load with sliding distance significantly influenced the wear rate of AlSi10Mg in both counter body cases. The adhesion and abrasion wear mechanism were observed in AlSi10Mg with EN-31 and silicon carbide abrasive sheet, respectively. The findings reveal the effect of two counter bodies on the SLMed AlSi10Mg wear phenomenon. Finally, severe wear was observed in the AlSi10Mg pin against the silicon carbide counter body.


2015 ◽  
Vol 1095 ◽  
pp. 48-52
Author(s):  
Chun Yan Tian ◽  
Hai Jiang

Silicon nitride nanoceramics were prepared by hot press sintering amorphous Si3N4and α-Si3N4nanopowders. The microstructures as well as the effect of starting powders size on the mechanical properties and thermal fatigue properties were investigated. The results show that microstructure of sintered materials consists of spherical grains with approximate size of 100 nm. The mechanical properties and thermal fatigue resistance vary with the addition of α–Si3N4powders. The maximum flexural strength and fracture toughness are obtained when the α–Si3N4powders amount is 40wt.%. And the Si3N4nanoceramic added 40wt.% α–Si3N4powders has the best capability to suppress crack propagation and the highest critical temperature difference.


2007 ◽  
Vol 546-549 ◽  
pp. 2179-2182 ◽  
Author(s):  
Ling Bai ◽  
Xing Yu Zhao ◽  
Chang Chun Ge

Sintering of the Self-Propagating High-Temperature Synthesis (SHS) of β-Si3N4 powder with 6.67 wt.% Y2O3 and 3.33 wt.% Al2O3 as sintering additives has been emphatically investigated using hot-press sintering process. The relative density of hot-pressed β-Si3N4 reached near to the full densification (99.43%) at 1700°C. The similar micrographs with self-reinforcing rod-like β-Si3N4 grains forming an interlocking structure were observed. The better mechanical properties of hot-pressed Si3N4, such as the hardness (16.73GPa), fracture toughness (5.72 MPa·m1/2) and bending strength (611.72MPa) values, were obtained at 1700°C. The results indicate that good sinter ability can be obtained with the cheaply SHS of silicon nitride powder for preparing silicon nitride materials, which will make the cost of silicon nitride materials lowered.


2007 ◽  
Vol 561-565 ◽  
pp. 563-566
Author(s):  
Zhen Ying Huang ◽  
Hong Xiang Zhai ◽  
Hua Zhang ◽  
Hong Bing Zhang

The current-carrying wear characteristics of Ti3AlC2 sliding against low-carbon steel were investigated. Tests were carried out using a block-on-disk type friction tester, with sliding speeds of 20~60 m/s, normal pressures range in 0.4~ 0.8 MPa, and the current intensity of 0 A, 50 A and 100 A. The Ti3AlC2 showed good current-carrying wear properties. At the sliding speed of 20 m/s, the wear rate of the Ti3AlC2 (× 10-6 mm3/Nm) was varied in the range of (2.05 ~ 2.41), (2.64 ~ 2.39) and (6.26 ~ 3.62), under the current of 0 A, 50 A and 100 A, respectively. Both the surfaces of Ti3AlC2 and the steel were covered by a frictional film, which was consisted of iron titanate (Fe2.25Ti0.75O4) and aluminum iron oxide (AlFeO3). The wear rate of Ti3AlC2 with current was composed of two parts: the interaction of micro-arc ablation and mechanical friction, and the coupled action of thermal and mechanical effect. Which one will be the main mechanism depends on the material parameters of Ti3AlC2 and the mechanical parameters such as the normal pressure or the sliding speed.


2005 ◽  
Vol 46 (9) ◽  
pp. 2041-2046 ◽  
Author(s):  
Mitsuo Kido ◽  
Tarou Tokuda ◽  
Rongguang Wang ◽  
Fumihiro Suzumura

2007 ◽  
Vol 539-543 ◽  
pp. 2687-2692
Author(s):  
Tarou Tokuda ◽  
Mitsuo Kido ◽  
Rong Guang Wang ◽  
Gonojo Katayama ◽  
Fumihiro Suzumura

2012 ◽  
Vol 217-219 ◽  
pp. 239-244
Author(s):  
Hai Jiang ◽  
Chun Yan Tian

Silicon nitride nanoceramics were fabricated by hot press sintering two kinds of Si3N4nano-sized powders. The effect of starting powders on microstructure, mechanical properties and thermal shock resistance were investigated. The microstructure of sintered materials consists of spherical grains and the addition of α–Si3N4to starting powders does not affect the grain morphology. The flexural strength, fracture toughness and thermal shock resistance increase with the increase in amount of α–Si3N4starting powders, and the maximum mechanical properties are obtained when the amount of α–Si3N4 powders is 40wt.%. The hardness values decrease with the increase of α–Si3N4amount.


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