固态渗碳对Ti-6Al-4V合金及其复合材料（TiB+La2O3）Ti-6Al-4V表面显微组织和硬度的影响.pdfVIP

Trans. Nonferrous Met. Soc. China 26(2016) 1871− 1877 Effect of solid carburization on surface microstructure and hardness of Ti−6Al−4V alloy and (TiB+La O )/Ti−6Al−4V composite 2 3 Hong-qiang DUAN, Yuan-fei HAN, Wei-jie LÜ, Jian-wei MAO, Li-qiang WANG, Di ZHANG State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China Received 2 July 2015; accepted 11 April 2016 Abstract: Solid carburization was employed to improve the hardness of Ti−6Al−4V alloy and (TiB+La O )/Ti composite. The 2 3 samples wrapped in graphite powder were placed in sealed quartz tubes, followed by solid carburization at 1227 K for 24 h. Microstructure and phase analysis indicated that TiC reinforcements and Ti−C solid solutions were introduced after solid carburization. Moreover, the volume fraction of equiaxed α-Ti phase in diffusion layer decreased obviously with increasing sample depth. Hardness testing results indicated that both the carburized surfaces performed significant improvement of about 100% in micro-hardness compared with untreated materials. The variation of carbon contents with increasing sample depth resulted in a hardened layer of 300 μm in the carburized samples. Meanwhile, slight influence on the internal microstructure and hardness indicated that solid carburization was an effective method in strengthening the surface of titanium alloy and titanium matrix