(西北工業(yè)大學(xué) 凝固技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，西安 710072)
摘 要: 研究塊體Ti40Zr25Ni8Cu9Be18非晶合金在液氮溫度下的準(zhǔn)靜態(tài)壓縮力學(xué)行為，并對不同應(yīng)變速率時(shí)的低 溫力學(xué)性能和室溫性能進(jìn)行對比。結(jié)果表明：塊體Ti40Zr25Ni8Cu9Be18非晶合金在低溫時(shí)的壓縮強(qiáng)度明顯高于室溫時(shí)的壓縮強(qiáng)度；且隨著應(yīng)變速率的增大，低溫壓縮強(qiáng)度增加的幅度較大，即正應(yīng)變速率敏感因子增大；在液氮溫度和低應(yīng)變速率條件下，光滑斷面的出現(xiàn)說明低溫對降低粘度起著阻礙作用，粘度降低的量級沒有達(dá)到形成脈狀花樣所需要的要求；隨著應(yīng)變速率的增加，剪切斷口脈狀花樣的出現(xiàn)說明高應(yīng)變速率能夠明顯降低剪切面粘度。
關(guān)鍵字: 鈦基非晶合金；壓縮強(qiáng)度；液氮溫度；力學(xué)性能
bulk metallic glass at cryogenic temperature
（State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The compressive mechanical behaviors of the Ti40Zr25Ni8Cu9Be18 bulk metallic glass(BMGs) at cryogenic temperature and different strain rates were investigated, and the mechanical properties at temperature and different strain rate were compared with those at room temperature. The results show that the compressive strength at cryogenic temperature is higher than that at room temperature, the compressive strength at cryogenic temperature increases linearly with increasing strain rates, and the positive strain rate sensitivity exponent increases. The observed smooth failure surface demonstrates that the cryogenic temperature effectively restrains the decrease of the viscosity, and the decreased viscosity do not reach the requirement of forming the vein-like patterns, which is different from that of the deformation character at room temperature. With increasing strain rate, the appearance of vein-like patterns reveals that high strain rates can decrease the viscosity of shear surface.
Key words: Ti-based metallic glasses; compressive strength; cryogenic temperature; mechanical properties
