Tribological characteristics of SiC ceramics sintered with a small amount of yttria
Tribological characteristics of SiC ceramics sintered with a small amount of yttria
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DOI：
10.1016/j.ceramint.2015.07.210
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发表时间：
2015-12
影响因子：
5.2
通讯作者：
Supriya Gupta;Sandan Kumar Sharma;B. Kumar;Young‐Wook Kim
中科院分区：
文献类型：
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作者：
Supriya Gupta;Sandan Kumar Sharma;B. Kumar;Young‐Wook Kim
研究了添加少量氧化钇（0.2或3wt%）的热压烧结SiC陶瓷的力学性能和摩擦学性能。使用球盘摩擦试验机在无润滑滑动条件下对市售WC球在5-N、10-N或20- N载荷和0.1 m/s线速度下估计SiC陶瓷的摩擦和磨损性能。添加3wt%氧化钇的SiC陶瓷（3 Y-SiC）由等轴晶组成，而添加0.2wt%氧化钇的SiC陶瓷（0. 2 Y-SiC）则呈现双峰晶粒结构，并有部分晶粒被拉长。随着氧化钇含量从0.2重量%增加到3重量%，硬度从27.7 GPa降低到26.1 GPa，弯曲强度从580 MPa降低到542 MPa，断裂韧性从4.0 MPa m1/2增加到4.3 MPa m1/2。随着氧化钇含量或滑动载荷的变化，摩擦系数在0.4 ~ 0.5之间变化，比磨损率在1.8×10− 6 ~ 6.7×10− 6 mm 3/Nm之间变化。在20 N载荷下，3 Y-SiC的比磨损率约为0. 2 Y-SiC的2倍。磨损表面分析表明，机械断裂作为一个主导机制的材料去除的SiC陶瓷在选定的滑动条件。摩擦磨损结果与烧结SiC陶瓷的显微结构和力学性能有关。
Mechanical and tribological properties of hot-pressed SiC ceramics sintered with a small amount of yttria (0.2 or 3 wt%) additive were studied. The friction and wear properties of the SiC ceramics were estimated under unlubricated sliding conditions against commercially available WC balls at 5-N, 10-N or 20- N load and 0.1 m/s linear speed using a ball-on-disk tribometer. SiC ceramics prepared with 3 wt% yttria (3Y–SiC) consisted of equiaxed grains, whereas SiC ceramics sintered with 0.2 wt% yttria (0.2Y–SiC) showed bimodal grain structure with some elongated grains. With increase in yttria content from 0.2 to 3 wt%, hardness decreased from 27.7 to 26.1 GPa, flexural strength decreased from 580 to 542 MPa, and fracture toughness increased from 4.0 to 4.3 MPa m1/2. The coefficient of friction varied from 0.4 to 0.5 and specific wear rate from 1.8×10−6to 6.7×10−6mm3/N m with change in yttria content or sliding load. The specific wear rate of the 3Y–SiC was approximately double than that obtained for the 0.2Y–SiC at 20 N load. Worn surface analysis indicated mechanical fracture as a dominant mechanism of material removal of SiC ceramics under the selected sliding conditions. The friction and wear results are related to the microstructure and mechanical properties of the sintered SiC ceramics.