(1. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150001；2. 哈爾濱工業(yè)大學(xué) 微納米技術(shù)研究中心，哈爾濱 150001)
摘 要: 利用新的金屬型微精密鑄造工藝制備微米尺度的ZnAl4微齒輪鑄件，并用納米壓痕儀測試微鑄件的硬度和彈性模量。結(jié)果表明，微齒輪鑄件不同部位的硬度表現(xiàn)出梯度性，隨晶粒尺寸的增加而減小，彈性模量的值比較分散。與常規(guī)尺寸鑄件的顯微硬度相比，微鑄件硬度明顯提高，最大達(dá)到1.70倍，而彈性模量則下降約50%。分析表明快冷造成的非平衡凝固組織是性能改變的主要原因。
關(guān)鍵字: ZnAl4；合金微精密鑄造；納米壓痕；納米硬度；彈性模量
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;2. Micro/nano Technology Research Center, Harbin Institute of Technology, Harbin 150001, China）
Abstract:Micrometer scale gear was manufactured by new micro-precision casting technology based on metal mold, and its hardness and elastic modulus were measured by nanoindentation. The results show that the hardness of microcastings is dependent on the grain size, and decreases with the increase of the grain size. Value of elastic modulus scattered. The hardness of microcastings is higher than that of conventional castings, the maximum up to 1.70 times, but the elastic modulus decreases by about 50%。The property change is caused by the microstructure of non-equilibrium solidification from rapid cooling.
Key words: ZnAl4 alloy; micro-precision casting; nanoindentation; nanohardness; elastic modulus
