烧结温度对Al_(3)(Zr,Ti)/2024Al复合材料组织与性能的影响

Effect of sintering temperature on microstructure and properties of Al_(3)(Zr,Ti)/2024Al composites

以2024铝合金粉末为基体材料,纯Zr粉和纯Ti粉作为增强体材料,采用粉末冶金的方法制备出了Al_(3)(Zr,Ti)/2024Al复合材料。通过对Al-Ti-Zr三元体系进行差示扫描量热分析(DSC),确定了初步烧结温度。利用X射线衍射(XRD)、扫描电镜(SEM)、能谱仪(EDS)、万能拉伸试验、显微硬度仪以及电化学性能测试等研究了烧结温度对复合材料组织与性能的影响。结果表明:随着烧结温度的升高,复合材料的抗拉强度和硬度均呈现出先增大后减小的趋势,耐腐蚀性能呈现出先上升后下降的趋势。当烧结温度为850℃时,复合材料的抗拉强度、硬度和腐蚀电位达到最大,分别为458.06 MPa、149.8 HV0.01和-0.451 V,腐蚀电流密度为1.888×10^(-6) A/cm^(2)。随着烧结温度的升高,复合材料的致密度呈现出上升的趋势,孔隙度呈现出下降的趋势,当烧结温度为950℃时,复合材料的致密度达到了98.88%,孔隙度下降到了1.12%,说明烧结温度的适当提高可以使复合材料的致密度提高。

Al_(3)(Zr,Ti)/2024Al composites were prepared by powder metallurgy with 2024 aluminum alloy powder as matrix material and pure Zr powder and pure Ti powder as reinforcement materials.The initial sintering temperature of the composites was determined by the differential scanning calorimetry(DSC)analysis of Al-Ti-Zr ternary system.The effects of sintering temperature on microstructure and properties of the composites were studied by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)analysis,universal tensile test,microhardness tester and electrochemical performance test.The results show that with the increase of sintering temperature,the tensile strength,hardness and corrosion resistance of the composites first increase and then decrease.When the sintering temperature is 850℃,the tensile strength,hardness and corrosion potential of the composites reach the maximum,which are 458.06 MPa,149.8 HV0.01 and-0.451 V,respectively,and the corrosion current density is 1.888×10^(-6) A/cm^(2).With the increase of sintering temperature,the densification of the composites shows an upward trend and the porosity shows a downward trend.When the sintering temperature is 950℃,the densification of the composites reaches 98.88%and the porosity decreases to 1.12%,indicating that the appropriate increase of sintering temperature can improve the densification of the composites.