(北京科技大學 材料科學與工程學院， 北京 100083)
摘 要: 采用小沖桿試驗法(SPT)研究了大塊非晶合金(Zr41.2Ti13.8Cu12.5Ni10Be22.5)在不同溫度和不同壓頭速度下的變形行為， 通過SPT載荷—位移曲線結(jié)合理論分析， 確定大塊非晶(BMG)材料超塑性本構(gòu)關(guān)系。 結(jié)果表明， BMG材料的SPT載荷—位移曲線對壓頭速度和實驗溫度的敏感性較高， 而SPT載荷—位移曲線的形狀與材料的應變速率敏感系數(shù)、 粘度、 壓頭速度等因素有關(guān)。 在應變速率敏感系數(shù)和壓頭速度固定的條件下， SPT最大破裂載荷與粘度成正比； 最大破裂位移僅隨應變速率敏感系數(shù)的增大而增大， 而與壓頭速度和粘度的大小無關(guān)。 獲得了Zr41.25Ti13.75Ni10Cu12.5Be22.5 BMG應變速率敏感系數(shù)和表觀粘度， 確定了該合金的超塑性本構(gòu)關(guān)系。
關(guān)鍵字: 小沖桿試驗； 大塊非晶合金； 超塑性； 本構(gòu)關(guān)系
（ School of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083）
Abstract: The deforming behaviors of Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass(BMG) under different temperatures and punch velocities were investigated by the small punch test. Based on SPT load—displacement curves and combined with theoretical analysis, a method for determining super-plastic constitutive relations of BMG was proposed. The results show that the SPT load—displacement curves of BMG are very sensitive to punch velocity and test temperature, and the shape of SPT load—displacement curves is controlled by strain rate sensitivity, viscosity and punch velocity etc. When the strain rate sensitivity and punch velocity are certain, maximal crack loads of SPT load—displacement curves are proportional to viscosities. Maximal crack displacement increases with the increase of strain rate sensitivity, and is independent on punch velocity and viscosity. The strain rate sensitivities and viscosities of Zr41.2Ti13.8Cu12.5Ni10Be22.5 BMG under different test conditions are obtained, and the super-plastic constitutive relations of the alloy are determined.
Key words: small punch test; bulk metallic glass; super-plasticity; constitutive relation
