热处理对钛基复合材料组织和性能的影响

Effect of Heat Treatment on Microstructure and Mechanical Properties of Titanium Matrix Composites

通过对5vol%(TiC+TiB)/Ti-6Al-4V试样进行不同热处理,从而研究热处理对其组织和力学性能的影响。研究结果发现:钛基复合材料淬火后组织主要是由针状马氏体α'构成,回火后一方面晶格畸变发生回复,另一方面α'相转变为板条状α相,并且随着回火温度的上升,α板条粗化;由于组织的变化造成硬度随回火温度的升高先降低后上升,而屈服强度先上升后下降,抗拉强度则先上升后变化趋缓。热处理对钛基复合材料的断裂机制影响不大,钛基复合材料都是解理断裂为主;回火转变使延伸率下降,但提高回火温度又会造成钛基复合材料断裂伸长率增加。

The effects of heat treatment on the microstructure and mechanical properties of(TiC+TiB)/Ti-6Al-4V composites were studied by different heat treatments.The results show that the quenched titanium matrix composites are mainly composed by acicular martensite withα’structure.The lattice is recovered after tempering,as well as theα’phase turns toαlamellar structure.With the increase of tempering temperature,αlaths coarsen.Due to the change of the microstructure,the hardness of titanium matrix composites decreases firstly and then increases with the increase of tempering temperature,while the yield strength firstly increases and then decreases,and the tensile strength increases at first and then the change becomes smooth.The fracture is of characteristics of cleavage fracture,which is unaffected by the changing of heat treatment temperature.The elongation is decreased after temper process,but it will go up with the increase of tempering temperature.