超声辅助激光沉积原位TiC-TiB2/Al-12Si铝基复合材料微观组织及摩擦磨损行为研究

Investigation on the microstructure and friction wear behavior of in-situ TiC-TiB2/Al-12Si composites fabricated by ultrasonic assisted laser deposition

摘要:

以Ti、B₄C和Al-12Si粉末为原材料,通过超声辅助激光沉积制备了原位TiC-TiB₂/Al-12Si铝基复合材料。采用XRD、EDS分析了复合材料的物相组成,通过OM、SEM观察了复合材料的微观组织,利用摩擦磨损试验机和三维轮廓仪测试了复合材料的磨损性能。结果表明,随Ti+B₄C含量的增加,ɑ-Al晶粒细化,原位生成的TiB₂呈棒状,且可成为ɑ-Al的异质形核核心；原位生成的TiC为150nm多边形形貌。随Ti+B₄C含量的增加,原位TiC-TiB₂/Al-12Si铝基复合材料的耐磨性提高；未加入Ti+B₄C的Al-12Si合金磨损机制为粘着磨损；当Ti+B₄C的加入量为8wt.%时,磨损机制为磨粒磨损；当Ti+B₄C的加入量为10wt.%时,其磨损机制转变为粘着磨损。

Abstract:

In-situ TiC-TiB₂/Al-12Si composites were fabricated by ultrasonic assisted laser deposition using Ti、B₄C and Al-12Si powders as precursor materials at different proportions. The phase constitution, microstructure, frictional wear behavior of the composites were analyzed using X-ray diffraction (XRD), energy dispersive spectrum (EDS), optical microscope (OM), scanning electron microscope (SEM), friction and wear testing machine and 3D profile measurement. The results show that the α-Al phase is refined with the increasing of Ti+B₄C, rod-like TiB₂ synthesized in-situ can act as the heterogeneous nucleation core of α-Al phase. The TiC synthesized in-situ is a polygonal shape of 150nm. The wear resistance of in-situ TiC-TiB₂/Al-12Si composites is improved. The wear mechanism of Al-12Si alloy without Ti+B₄C addition is adhesive wear, and the wear mechanism of TiC-TiB₂/Al-12Si composites changes from adhesive wear to abrasive wear when the addition of Ti+B₄C is 8wt.%. When the addition of Ti+B₄C is 10wt.%, the wear mechanism of TiC-TiB₂/Al-12Si composites is adhesive wear.