等径角挤压工艺对Ti5553合金冲蚀磨损性能的影响

Influence of Equal Channel Angular Extrusion on Erosion Wear Resistance of Ti5553

考察了经等径角挤压(ECAE)处理前后的Ti5553合金在含泥沙海水环境中的冲蚀磨损特性,采用扫描电子显微镜观察冲蚀磨损后的试样表面形貌并结合MATLAB软件进行定量分析,探讨了Ti5553合金显微组织、力学性能及冲蚀机理的演变对其冲蚀磨损性能的影响.结果表明:经ECAE处理后,Ti5553合金的抗冲蚀磨损性能明显提高,这是由于ECAE工艺能够通过细晶强化而提高Ti5553合金的强度与韧塑性、改善其微观组织所致;未经ECAE处理的Ti5553合金的冲蚀磨损机理为冲击变形及犁沟剥落,并伴随大面积划痕和冲击坑裂纹的产生,而经ECAE处理的Ti5553合金的冲蚀机理为轻微冲击变形及犁沟剥落,划痕和冲击坑裂纹的扩展趋势不明显.

A novel method was proposed to improve the erosion wear behaviour of Ti5553 exposed to seawater with quartzes, in which the erosion performance of Ti5553 treated by equal channel angular extrusion （ECAE） was compared with that of counterpart without ECAE treatment. The results indicate that the sample treated by ECAE demonstrates a significantly improved erosion wear resistance due to the grain refinement introduced by ECAE, resulting in the improvement of tensile strength, ductility, toughness and microstructure of the sample. Scanning electron microscope （SEM）, assisted by quantitative analysis utilising Matlab, was adopted to generate the surface morphology of the samples. With the exploration of the microstructure, mechanical properties and erosion mechanism evolution dependence of erosion wear behaviour, it is found that the erosion mechanism of the sample treated by ECAE has impact deformation and ploughing, accompanied by severe scratching and crater cracks while that of the sample without ECAE treatment has slight impact deformation and ploughing, with shallow scratching and crater cracks.