骨传导蓝牙耳机镍钛合金后挂在组装后出现发软现象,并在疲劳试验时发生早期断裂。采用宏观观察、化学成分分析、拉伸试验、金相检验、断口分析及能谱分析等方法,对该耳机后挂断裂的原因进行了分析。结果表明:耳机镍钛合金后挂的原材料在轧制过程中形成折叠缺陷,在随后的拉拔过程中折叠缺陷不断向材料内部延伸扩展,形成纵向裂纹,使材料承受外力的能力降低,导致耳机后挂在使用时出现发软现象,并在疲劳试验时发生早期断裂。

The Ni-Ti alloy hung of a bone conduction bluetooth earphone appearred to be soft after assembly,and early fracture occurred during fatigue test.By means of macroscopic observation,chemical composition analysis,tensile test,metallographic inspection,fracture analysis,energy spectrum analysis and so on,the reasons for fracture of earphone were analyzed.The results showed that the raw material of Ni-Ti alloy hung of the earphone form folding defects during the rolling process.During the subsequent drawing process,the folding defects continued to extend to the inside of the material,forming longitudinal cracks,and the ability of the material to withstand external forces was reduced.As a result,the earphone hung appearred to be soft when it was in use,and early fracture occurred during the fatigue test.