冷却速率对Sn-3.5Ag合金微观组织及力学性能的影响

Effects of Cooling Rate on Microstructure and Mechanical Behavior of Sn-3.5Ag Alloy

摘要:

研究了不同冷却速率对Sn-3.5Ag合金的微观组织、维氏硬度和力学性能的影响。通过采用空冷、水冷和急冷的方式获得了冷却速率分别为101、103和106 K/s的Sn-3.5Ag合金样品，对样品进行显微分析和力学性能测试后得出冷却速率对β-Sn二次枝晶臂间距和Ag3Sn相的分布有显著影响。随冷却速率的加快，β-Sn晶粒尺寸和二次枝晶臂间距逐渐减小，Ag3Sn晶粒尺寸也逐渐变小、分布更加均匀，样品硬度、力学性能也随冷却速率的增加而提高。研究结果表明，合金微观组织结构和Ag3Sn相的分布规律对合金力学性能有显著的影响，Ag3Sn相在合金中起了弥散强化的作用

Abstract:

The microstructure, micro-hardness and tensile behavior of bulk Sn-3.5Ag alloy were studied as a function of cooling rate. Sn-3.5Ag alloy samples with the controlled cooling rates of 101, 103 and 106 K/S of were obtained by cooling specimens in different media: air, water and rush cold. The microscopic analysis and mechanical properties test were conducted. Results show that the cooling rat has a significant effect on the secondary dendrite size and distribution of β-Sn phase. The β-Sn grain average size and the secondary dendrite arm space are gradually reduced with the increase of cooling rate, Ag3Sn grain also become smaller, and distribute more uniformly. Besides, the micro-hardness and tensile properties with increasing cooling rate improve. Finally, it is concluded that the microstructure and the distribution of Ag3Sn grains influence obviously the mechanical properties, and Ag3Sn grains play a dispersion strengthened role in the alloy