Cu/Al复合材料高温短时退火的组织与性能演变研究

Study on microstructure and property evolution of Cu/Al composite during high-temperature short-time annealing

摘要:

将冷轧法制备的Cu/Al复合材料在475-525℃温度下退火1-8min,采用有限元软件模拟了Cu/Al复合材料在退火过程中的温度场,并采用扫描电镜(SEM)、X射线衍射仪(XRD)、能谱仪(EDS)、电子背散射衍射(ESBD)、显微硬度计等研究了Cu/Al复合材料的显微组织与力学性能。结果表明：在Cu/Al复合材料界面依次生成了CuAl<sub>2</sub>、Cu<sub>9</sub>Al<sub>4</sub>和CuAl等3种金属间化合物,在Cu/Al界面层厚度小于4μm的退火工艺范围内,Cu和Al基体发生完全再结晶形成等轴晶,Cu、Al基体的显微硬度能够迅速的降低至低温长时间(350℃、1h)退火的硬度。另外,提出了金属间化合物初生相的形核机理,分析计算了高温短时退火工艺下的形核动力学,并提出了非等温条件下的金属间化合物生长厚度的经验数值方法。

Abstract:

The cold-rolled Cu/Al laminated composite was annealed at 475-525℃ for 1-8min, the temperature field of Cu/Al composite during annealing was simulated using finite element software, and the microstructures and properties of Cu/Al composite were investigated by scanning electron microscopy(SEM), energy dispersive X-ray spectrometry(EDS), X-ray diffractometer(XRD), electron back-scattered diffraction(EBSD) and microhardness tester. The results indicated that three intermetallic compounds (IMCs), CuAl<sub>2</sub> ,Cu<sub>9</sub>Al<sub>4</sub> and CuAl phases formed successively at the Cu/Al interface, complete recrystallization of both the Cu and Al matrix took place to form equixed grain, within the annealing process scope in which the thickness of IMCs layer is smaller than 4μm, the microhardness of Cu and Al matrix drops fast to approach that of annealing at 350℃ for 1h.Therefore, the high-temperature short-time annealing process could substitute for low-temperature long-time annealing process. Furthermore,the nucleation mechanism of primary phase was proposed and the kinetics of IMCs during high-temperature short-time was analytized and calculated, and an empirical numerical method was proposed to calculate the thickness of IMCs during the non-isothermal annealing process.