蠕变对巴氏合金ZChSnSb11-6力学性能和显微组织的影响

摘要

针对巴氏合金ZChSnSb11-6工作过程中的蠕变现象，对合金进行蠕变实验。基于蠕变实验所得蠕变曲线，证实ZChSnSb11-6在实际工作条件下会发生明显的蠕变现象，同时利用WDW-E100D试验机，获得ZChSnSb11-6蠕变前后的屈服强度等力学性能。通过分析合金蠕变、力学性能和显微组织之间的关系，得知蠕变明显降低ZChSnSb11-6的强度、塑性及抗弹性变形能力，并得到合金蠕变机理，明确ZChSnSb11-6蠕变变形是应变硬化与再结晶回复长时间交替作用的结果。通过计算合金的应变硬化指数，证实蠕变使合金均匀变形的能力降低，增大合金发生断裂破坏的可能性。同时，基于硬度试验获得合金硬度随温度变化的计算公式，确定ZChSnSb11-6的蠕变临界温度范围为50~60℃。通过观察ZChSnSb11-6蠕变前后的显微组织，发现蠕变使合金组织中SnSb和Cu 6 Sn 5明显减少，导致合金力学性能降低。%According to the creep phenomenon of Babbitt alloy ZChSnSb11-6 in operation, the creep experiment of ZChSnSb11-6 was carried out. Based on the creep behavior of ZChSnSb11-6, the results validate that such alloy will produce obvious creep during its actual operation. Meanwhile, the mechanical performances, such as yield strength of ZChSnSb11-6 before and after creep, were acquired by using WDW-E100D testing machine. The relationships among creep, mechanical performances and microstructure of alloy were analyzed. The results show that the strength, plasticity and elastic deformation resistance of ZChSnSb11-6 were obviously decreased by creep. What is more, the creep mechanism of ZChSnSb11-6 is obtained, which indicates that the creep deformation of ZChSnSb11-6 is the result of long-time alternative reactions of strain-hardening and recrystallization reply. The strain hardening exponents of ZChSnSb11-6 were calculated. It is verified that the affine deformation capability of alloy decreases. The fracture possibility of alloy increases. At the same time, the calculation formula of alloy hardness change with the temperature is acquired by hardness test of ZChSnSb11-6. The critical temperature of ZChSnSb11-6 creep was determined to be within 50−60℃. The microstructure of ZChSnSb11-6 before and after creep was observed. The results show that SnSb and Cu6Sn5 of ZChSnSb11-6 reduce significantly, and the mechanical properties of alloy decrease.