变形量对半固态CuSn10合金组织和性能的影响

材料的组织形态直接影响零件的性能,本文采用自主研发的熔体约束诱导形核半固态制浆装置制备CuSn10半固态浆料并流变挤压成薄板,然后在350℃下轧制变形,研究变形量对微观组织和性能的影响。结果表明,随着变形量增加,变形板件内部缩松缩孔等铸造缺陷逐渐减少减小、晶粒呈现压缩拉长趋势、平均晶粒厚度从初始未变形时30.58μm到变形量ε=0.4时的22.12μm。随变形量的加大在初生相内部产生的形变孪晶数量逐渐增加。在变形量从ε=0增加到ε=0.4的过程中,CuSn10合金组织内小角度晶界占比逐渐占优,引入了大量的亚结构和位错密度。在变形量ε=0.4时,可以发现极图{110}和{111}存在[101]、[111]和[001]织构。在板材力学性能方面,板材的屈服强度、抗拉强度和硬度不断增加；但塑性呈现下降的趋势。变形量ε=0.4时,其屈服强度、抗拉强度和布氏硬度分别达到了443MPa、554MPa、194HBW,相较于初始未变形薄板其屈服强度、抗拉强度和硬度分别提高了106.1%、66.4%、41.6%,延伸率降低至0.82%。半固态CuSn10合金在变形过程中随变形量的增加强度、硬度不断提高、塑性持续降低,这主要是归功于在轧制变形过程中产生的晶粒细化和加工强化。

Effect of Deformation on the Microstructure and Properties of Semi-solid CuSn10 Alloys

The microstructure of materials has an effect on the properties of components. In this study, the effect of deformation on the microstructure and properties of semi-solid CuSn10 alloy was investigated. Semi-solid CuSn10 slurry was made by a self-developed enclosed cooling slope channel (ECSC) and cast into thin plates by rheological squeeze, then rolled at 350°C. The results showed that as deformation increased, casting defects such as shrinkage porosity and shrinkage cavities gradually decreased, with grains compressed and elongated, and their average thickness reduced, from 30.58 μm (undeformed) to 22.12 μm (ε=0.4). In addition, more deformation twins were found inside the primary phase with increasing deformation . As deformation increased from 0 to 0.4, a large amount of substructures and dislocation density was introduced into the CuSn10 alloy microstructure. At ε=0.4, textures [101], [111], and [001] were found in pole figures {110} and {111}. The mechanical properties of the plate, including yield strength, tensile strength, and hardness increased. At the deformation of 0.4, the three properties reached 443 MPa, 554 MPa, and 194 HBW, respectively, up by 106.1%, 66.4%, and 41.6%, compared with those without receiving deformation. But the plasticity of the plate was on the decline, and its elongation decreased to 0.82%. The changes in the alloy are mainly attributed to work hardening and refined grains produced during the rolling deformation.