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对粉末冶金制备的Cu/Invar复合材料,进行变形量至70%的轧制及750°C退火处理,研究在此工艺过程中复合材料物相、组织结构及性能的变化。研究结果表明,轧制和退火处理后的Cu/Invar复合材料中体心立方(BCC)α-Fe(Ni,Co)相明显减少,部分Ni原子从Cu中脱溶,并溶入α-Fe(Ni,Co)中,促使其向面心立方(FCC)的Invar合金转变。Cu/Invar复合材料的轧制变形过程分为3个阶段:当变形量小于40%时,Cu发生塑性变形,Invar颗粒随之发生位移,且颗粒间的气孔逐渐被压合;当变形量为40%~60%时,Invar合金和Cu发生协调变形,形成流线形结构;当变形量大于60%时,以Invar的变形为主,形成双连续网络状结构。经过变形量为70%的轧制及随后退火处理的Cu/Invar复合材料相对密度为98.6%,抗拉强度为360 MPa,伸长率为50%,热导率为25.42W/(m·K),热膨胀系数为10.79×10-6 K-1。
The Cu / Invar composites prepared by powder metallurgy were subjected to rolling deformation of up to 70% and annealing at 750 ° C to investigate the changes of the phase, structure and properties of the composites during the process. The results show that the volume fraction of BCC α-Fe (Ni, Co) in the Cu / Invar composites after rolling and annealing decreases obviously, some of the Ni atoms desolve from Cu and dissolve in α-Fe (Ni, Co), prompting its transformation to face-centered-cubic (FCC) Invar alloys. The deformation process of Cu / Invar composite is divided into three stages: when the deformation is less than 40%, the plastic deformation occurs in Cu and the Invar particles displace accordingly, and the stomata between particles are gradually compressed; when the deformation is At 40% ~ 60%, Invar alloy and Cu co-deform to form a streamlined structure. When the deformation is more than 60%, the deformation of Invar is dominant and the bicontinuous network structure is formed. The relative density of Cu / Invar composite after rolling and subsequent annealing at 70% deformation was 98.6%, tensile strength was 360 MPa, elongation was 50%, and thermal conductivity was 25.42 W / (m · K ), Thermal expansion coefficient of 10.79 × 10-6 K-1.