快速凝固Cu-Sn亚包晶合金的电阻率及力学性能

Electrical resistivity and mechanical properties of rapidly solidified Cu-Sn hypoperitectic alloys

定量表征了快速凝固Cu-xwt%Sn(x=7,13.5,20)亚包晶合金的电阻率和力学性能,理论分析了冷却速率与合金性能之间的关系.研究结果表明,在急冷快速凝固条件下,随着冷却速率的增大,合金组织显著细化、晶界增多,对自由电子的散射作用增强,Cu-Sn亚包晶合金的电阻率升高.当晶界散射系数取r=0.992时,可用M-S模型分析其电阻率.同时,细晶强化作用增强,合金的显微硬度和抗拉强度呈线性增大,并且细晶区显微硬度略大于粗晶区显微硬度.冷却速率的增大使合金的伸长率减小,其值在1.0%—4.6%范围.

The electrical resistivity, microhardness, tensile strength and elongation of rapidly solidified Cu-xwt. %Sn （x = 7, 13.5, 20） hypoperitectic alloys are investigated, and the relationships between cooling rate and properties of the alloys are further analyzed theoretically. It is found that, under rapid solidification, the microstructure is refined and the amount of grain boundary increases, and the scattering of free electrons is thus intensified, resulting in the rise of alloy resistivity. Provided that the value of grain boundary reflection coefficient r is about 0. 992, the electrical resistivity of the alloys can be theoretically analyzed by the M-S model. With the increase of cooling rate, the microhardness and tensile strength of alloy foils increase linearly, but the elongation decreases within the range of 1.0%--4.6 %.