铸锻复合对ADC12铝合金显微组织和性能的影响

发布时间：2018-05-15 18:26

本文选题：间接挤压铸造 + 锻造　；参考：《特种铸造及有色合金》2017年02期

【摘要】：通过铸锻复合工艺加工ADC12铝合金,该工艺包括间接挤压铸造和锻造,分别对重力铸造态、挤压铸造态和铸锻复合态的ADC12铝合金的力学性能和显微组织进行了研究。结果表明,挤压铸造的ADC12铝合金具有更细的Al-Si共晶组织,针状共晶组织减少,其平均晶粒尺寸为37.25μm,较重力铸造态降低了36.51%,其抗拉强度和伸长率分别为240MPa和1%,较重力铸造的分别提高了34.08%和14.9%;铸锻复合后,组织进一步细化,Al-Si共晶组织被压碎,其平均晶粒尺寸为26.54μm,较重力铸造降低了28.75%,其抗拉强度和伸长率分别达到287.75 MPa和4.4%,较挤压铸造态分别提高了19.8%和340%。从拉伸断口形貌上可发现,铸态断口为典型的脆性断口,挤压铸造和铸锻复合后,都属准解理断裂,但是铸锻复合后,韧窝更浅而小,解理面和撕裂棱变得细小,断裂单元变小,韧性断裂趋势增加。经分析,晶粒细化及Al-Si共晶组织分布状态的改变是ADC12合金抗拉强度和伸长率提高的主要因素。
[Abstract]:ADC12 aluminum alloy was machined by casting and forging process. The mechanical properties and microstructure of ADC12 aluminum alloy in gravity casting state, squeeze casting state and cast forging state were studied respectively. The results show that the ADC12 aluminum alloy produced by squeeze casting has finer Al-Si eutectic structure and less acicular eutectic structure. The average grain size is 37.25 渭 m, which is 36.51 less than that of gravity casting, and its tensile strength and elongation are 240MPa and 1, respectively, which are 34.08% and 14.9% higher than those of gravity casting. The average grain size is 26.54 渭 m, which is 28.755.The tensile strength and elongation are 287.75 MPa and 4.4, respectively, which are 19.8% and 340% higher than those in squeeze casting. From the morphology of tensile fracture, it can be found that the as-cast fracture is a typical brittle fracture, and both of them belong to quasi-cleavage fracture after extrusion casting and casting forging, but after casting and forging, the dimple is shallower and smaller, and the cleavage surface and tearing edge become smaller. The fracture unit becomes smaller and the ductile fracture trend increases. The grain refinement and the change of Al-Si eutectic structure are the main factors to improve the tensile strength and elongation of ADC12 alloy.
【作者单位】：哈尔滨理工大学材料科学与工程学院;哈尔滨吉星机械工程有限公司;
【基金】：黑龙江省国际合作项目(2015WB15C104) 哈尔滨市科技攻关项目(2015AB4AG004)
【分类号】：TG146.21;TG249.2;TG319

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