低温时效对QBe2.0铍青铜组织与性能的影响

通过硬度测试、室温拉伸实验、电导率测试合金性能，以及借助OM、XRD、TEM等手段分析合金组织特征，研究QBe2.0合金在280 ℃下时效的组织与性能，结果表明:随着时效时间的延长，合金的硬度、屈服强度与抗拉强度持续上升，于8 h达到峰时效状态，主要强化相为以调幅组织的形式存在于基体中的γ’相；时效初期，基体中析出共格γ”相，引起严重的晶格畸变，使合金在时效过程中电导率先降低后升高；时效16 h后合金发生过时效，金相组织显示此时发生了较为严重的晶界反应，XRD图谱显示此时析出了少量平衡相γ，两者的共同作用使合金的力学性能下降. 

Effects of low temperature aging on the microstructure and properties of QBe2.0 alloy

The microstructure and properties of QBe2.0 alloy aging at the temperature of 280 ℃ were investigated. The room temperature tensile test, hardness testing and conductivity test were performed to measure the properties of the alloy, while the OM, XRD, TEM and other methods were used to analyze the microstructure. The results showed that with the prolonging of aging time, the hardness, yield strength and tensile strength of the alloy continue to increase, reaching the peak aging state at 8 h. The main strengthening phase was the γ' phase in the matrix in the form of amplitude-modulated structure. Since the lattice distortion was caused by coherent precipitated phase of γ〞, the conductivity of the alloy first decreased and then increased with the aging time. After 16 hours, the alloy reached the over-aged state. It was obvious to find that the discontinuous precipitation widely appeared at grain boundary and small amount of γ phase was detected in XRD pattern. Both two factors deteriorated the mechanical properties of the alloy.