摘要
The in-situ Al-based composites with different SiO2/C/Al molar ratios were fabricated by reaction hot pressing. The dry sliding wear characteristics of the composites were investigated using a pin-on-disc wear tester. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to investigate the surface composition and its morphology. The results show that when the SiO2/C/Al molar ratio is 3:6:9, more in-situ synthesized Al2O3 and SiC along with Si particles are produced, and Al4C3 is prevented completely from the Al?SiO2?C system. Thereby, a significant improvement of wear resistance is obtained. When the sliding velocity increases from 0.4 to 1.6 m/s, the wear loss decreases gradually. With increasing the normal load, the wear loss increases as well. Ploughing, craters and micro-grooving are observed as dominant abrasive wear mechanisms. Whereas, when a high velocity is employed, only the oxidation mechanism controls the wear behavior of the composites.
反应热压法制备不同SiO_2/C/Al摩尔比的原位自生铝基复合材料。采用销-盘式摩擦试验机对这些复合材料进行干滑动摩擦试验。利用扫描电镜和能谱分析研究复合材料表面成分和形貌。结果表明,当SiO_2/C/Al摩尔比为3:6:9时,原位生成更多Al_2O_3、SiC和Si颗粒,在Al-SiO_2-C体系中Al_4C_3相被彻底抑制,因此复合材料的耐磨性能大幅度提高。当滑动速度从0.4 m/s增加到1.6 m/s时,磨损量逐渐减小。当摩擦载荷增加时,磨损量也增加。观察到的犁沟、磨损坑和细微纹沟说明磨料磨损是主要的磨损机制。然而,当采用更高的滑动速度时,只有氧化磨损机制控制复合材料的磨损行为。
基金
Project (2012CB619600) supported by the Ministry of Science and Technology of China
Project (51201047) supported by the National Natural Science Foundation of China
Project (HIT.NSRIF.2013001) supported by the Fundamental Research Funds for the Central Universities China
Project (20110491038) supported by the Postdoctoral Science Foundation of China
