固溶处理对Cu-3.2Ni-0.75Si-0.3Zn合金组织及性能的影响

Effect of Solid Solution Treatment on Microstructure and Properties of Cu-3.2Ni-0.75Si-0.3Zn Alloy

研究了Cu-3.2Ni-0.75Si-0.3Zn合金时效前固溶温度和时间对该合金硬度及电导率的影响,并且分析了不同固溶条件之后时效对Cu-3.2Ni-0.75Si-0.3Zn合金性能的影响。结果表明:时效前固溶温度的升高,材料的电导率先较快下降,之后又回升,而硬度呈下降的趋势,当固溶温度到达925℃时,硬度下降缓慢;随着固溶温度的增加,其再结晶程度越来越高,到900℃时组织已是完全再结晶组织,温度继续升高,晶粒会发生长大;通过扫描电镜及能谱分析仪观察900℃固溶后的试样,发现只有少量析出相存在。而相对于固溶温度,固溶时间对合金性能的影响不明显。在不同固溶制度下,合金试样经冷变形和时效后,其电导率随固溶温度的升高先降后升,而抗拉强度和延伸率随固溶温度的升高会先升高后下降,固溶温度为925℃时试样的抗拉强度到达峰值,延伸率则在850℃时达到峰值。与其他固溶处理制度相比,合金在900℃×60 min固溶处理,经60%的冷变形,450℃×4 h时效处理后,可得到较好的综合性能。此时,合金抗拉强度达到762 MPa,延伸率为6.1%,电导率为32.5%IACS。

The effects of different solution temperature and time on the hardness and electrical conductivity of Cu-3.2Ni-0.75Si-0.3Zn alloy before aging were studied.At the same time,the influence of different solution conditions on properties of Cu-3.2Ni-0.75Si-0.3Zn alloy after aging was investigated.The results showed that electrical conductivity decreased rapidly at the beginning and then increased slightly with the increase of the solution temperature,but the hardness decreased all the time,and the hardness slowly declined after 925 ℃ solid solution treatment.With the increase of solid solution temperature,the degree of recrystallization was increased,the microstructure was fully recrystallized at 900 ℃;if temperature continued to rise,grains would grow up.There were a few precipitates in the solution sample at 900 ℃ observed by SEM and EDX,and the effect of solid solution time on properties was not sensitive.The electrical conductivity of samples after cold rolling and aging treatment decreased rapidly first and then increased with the increase of the solution temperature,tensile strength and elongation increased rapidly first and then decreased,tensile strength reached the peak at 900 ℃ solid solution treatment,and elongation reached the peak at 825 ℃.Compared with other solid solution conditions,the good overall properties could be obtained at 900 ℃ and 60 min solid solution treatment,60% cold-rolled deformation,450 ℃ and 4 h aging treatment.The finished strip’s tensile strength was 762 MPa,elongation was 6.1%,and electric conductivity was 32.5%IACS.