Effects of nano-alumina on mechanical properties and wear resistance of WC-8Co cemented carbide by spark plasma sintering

The present study investigates the high temperature tribological performance of spark plasma sintered, nano- and micron-sized tungsten carbide (WC) bonded by 9 wt.% cobalt (Co). The composites were fabricated using a two-step procedure of mixing followed by spark plasma sintering (SPS). Ball-on-disc wear tests were conducted at a normal load of 30 N, linear speed of 0.1 m/s under dry conditions and at three different temperatures (room temperature, 300 °C and 600 °C). Field emission scanning electron microscopy (FESEM), optical profilometry and energy dispersive X-ray (EDS) spectroscopy were used to analyze the surface morphology and the wear track area. At room temperature, it was observed that the nano-sized WC composites exhibited better wear resistance than the micron-sized WC composites. The wear resistance of the nano-sized samples declined significantly relative to that of the micron-sized samples with an increase in temperature. This decline in performance was attributed to the higher surface area of nano-sized WC particles, which underwent rapid oxidation at elevated temperatures, resulting in poor wear resistance. The wear rate observed at 600 °C for the micron-sized WC composites was 75% lower than that of the nano-sized cemented carbide. Oxidative wear was observed to be the predominant wear mechanism for both cemented carbide samples at elevated temperatures.

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Genetic Characteristics and Mechanical Properties of High-Siliconaluminum Alloy by Rapid Solidification and Spark Plasma Sintering

Materials Science Forum ◽

10.4028/www.scientific.net/msf.850.835 ◽

2016 ◽

Vol 850 ◽

pp. 835-840

Author(s):

Xiao Dong Zhang ◽

Yue Chi ◽

Zhan Kui Zhao

Keyword(s):

Mechanical Properties ◽

Wear Resistance ◽

Aluminum Alloys ◽

Spark Plasma Sintering ◽

Rapid Solidification ◽

Alloy Ribbon ◽

Genetic Characteristics ◽

Plasma Sintering ◽

Spark Plasma ◽

High Silicon

High-silicon aluminum alloys as light-weight structural materials are attractive because of their high wear resistance, low density and low thermal expansion. However, the Si phase in the high-silicon aluminum alloys always has big size, which deteriorates the mechanical properties and machinability of alloys. In this paper, alloy ribbon of high-silicon aluminum alloy with the composition of Al70Si30 was prepared by melt-spinning method. Then alloy ribbon was broken to powder by ball milling. The alloy powers were consolidated by spark plasma sintering (SPS) at different sintering parameters including time and temperature under vacuum atmosphere. The density, hardness and compression property of the compacts were investigated. The sintered samples were characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD), and compared with their alloy power and original alloy ribbons. The results showed that the density of Al70Si30 alloy, prepared under the condition of 320 °C and 500 MPa, was above 98%, the grain size was refined to sub-micron, and the wear resistance was good, micro-hardness was 311.70 Hv. It is believed that the existence of local high temperature and discharge plasma can break down and disrupt oxidation film on powder surface, and therefore improving the efficiency of sintering. In the case of large current, short time and low temperature, sintering grain growth was not obvious, there was less supersaturated solid solution precipitation and the rapid solidification microstructure , and the properties can be preferably reserved.

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Two-Step Spark Plasma Sintering Process of Ultrafine Grained WC-12Co-0.2VC Cemented Carbide

Materials ◽

10.3390/ma12152443 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2443 ◽

Cited By ~ 1

Author(s):

Zhenhua Wang ◽

Jiheng Jia ◽

Boxiang Wang ◽

Yulin Wang

Keyword(s):

Mechanical Properties ◽

Relative Density ◽

Spark Plasma Sintering ◽

Average Particle Size ◽

Cemented Carbide ◽

Cemented Carbides ◽

Average Particle ◽

Plasma Sintering ◽

Ultrafine Grained ◽

Spark Plasma

Ultrafine grained WC-12Co-0.2VC (named UYG12V) cemented carbides were prepared via the two-step spark plasma sintering (SPS) in this study. First, the effects of the sintering temperature on the relative density and WC grain size of UYG12V cemented carbides were studied. The results show that regular WC grains form when sintered at 1300 °C. The sintered body begins to rapidly densify and WC grains grow slowly when sintered at 1200 °C. Thus, the first-step (T1) and the second-step (T2) temperatures in the two-step SPS of UYG12V are 1300 °C and 1200 °C, respectively. The effect of the holding time during the first and second steps on the mechanical properties was also studied. The results show that the UYG12V cemented carbide sintered at 1300 °C for 3 min and then at 1200 °C for 5 min has the best comprehensive mechanical properties, exhibiting the average particle size, Vickers hardness, fracture toughness, relative density, and bending strength of 271 nm, 18.06 GPa, 12.25 MPa m1/2, 99.49%, and 1960 MPa, respectively.

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Mechanical Properties and Wear Resistances of TiC or B4C Reinforced Ti-6Al-4V Prepared by Spark Plasma Sintering

Materials Science Forum ◽

10.4028/www.scientific.net/msf.706-709.222 ◽

2012 ◽

Vol 706-709 ◽

pp. 222-227 ◽

Cited By ~ 1

Author(s):

Akinori Ota ◽

Hiroki Egawa ◽

Hiroshi Izui

Keyword(s):

Mechanical Properties ◽

Wear Resistance ◽

Spark Plasma Sintering ◽

Volume Fraction ◽

Ceramic Particle ◽

Specific Strength ◽

Plasma Sintering ◽

Spark Plasma ◽

High Initial Cost ◽

The Cost

Titanium and its alloys have excellent specific strength and corrosion resistance. However, they have a high initial cost and high machining cost, and poor wear resistance. Therefore, both factors should be considered in order to reduce the cost and improve the wear resistance of titanium alloy parts. Powder metallurgy (PM) has been taken into account for lowering the their costs. Titanium alloys reinforced with ceramic particle improves their wear resistance and hardness. In this study, we focus on the microstructures, mechanical properties, and wear resistance of TiC or B4C reinforced Ti-6Al-4V composites by using spark plasma sintering. The volume fraction of the reinforcement from 0 to 19.9 vol. %. The tensile strength of TiC/ and B4C/Ti-6Al-4V had 1058MPa (14.9 vol. % TiC) and 1095MPa (1.7 vol. % B4C), respectively. Vickers harnesses of TiC/ and B4C/Ti-6Al-4V increased with increase in the volume fraction of the reinforcement. The wear resistance of B4C/Ti-6Al-4V exhibited superior to that of TiC/Ti-6Al-4V.

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