Ti40(Ti-25V-15Cr-0.2Si)阻燃钛合金是β型钛合金。铸态组织中存在不同位向的孪晶,大孪晶中有许多平行的二次孪晶,沿孪晶界诱发微裂纹;高于850°C变形因动态回复形成了位错亚晶,变形温度越高亚晶越明显;850～1000°C变形孪晶与晶界交互作用及孪晶间的交互作用产生了微裂纹;孪晶的精细结构为位错;1100°C变形合金中不存在孪晶,在一些区域存在层错 Ti40 (Ti-25V-15Cr-0.2Si) flame retardant titanium alloy is β-type titanium alloy. As-cast twins with different orientation exist in the as-cast microstructure. There are many parallel twin twins in the large twins, which induce micro-cracks along the twin boundaries. When the temperature is higher than 850 ° C, dislocations and deformations are formed due to the dynamic recovery The higher the temperature is, the more obvious the sub-crystallites are. The deformation twin and grain boundary interaction at 850-1000 ° C and the interaction between the two twins produce microcracks; the fine structure of the twins is dislocations; the twins do not exist in the 1100 ° C deformation alloy , In some areas there is a fault