锻压变形量对铸锻成形A356铝合金组织及性能的影响

Effects of forging deformation amount on microstructure and mechanical properties of A356 aluminum alloy manufactured by casting-forging integrated technology

采用铸锻一体化成形技术制备A356铝合金汽车制动器卡钳,研究锻压变形量对卡钳的组织与力学性能的影响。结果表明,锻压变形量越大,锻压对模腔内凝固合金的强制性补缩效果越好,卡钳厚大部位的收缩裂纹越小,显微组织塑性变形越明显,卡钳的抗拉强度和伸长率越高。当变形量达到11.1%时,锻压能够完全压实愈合卡钳厚大部位的收缩裂纹,显微组织产生明显的塑性变形,枝晶晶粒破碎细化。当锻压变形量为17.3%时,锻压后卡钳的抗拉强度和伸长率分别为315.1MPa和6.4%,比未锻压卡钳的抗拉强度和伸长率分别增大了18.6%和30.6%。

The casting forging integrated technology was developed to manufacture A356 aluminum alloy automobile brake cali pers. The effects of forging deformation amount on microstructure and mechanical properties of A356 aluminum alloy automobile brake calipers were studied. The results show that, with the increasing of forging deformation amount, the forced feeding effect on the solidification alloys in die cavity is better, the shrinkage crack within calipers is smaller, the plastic deformation is obvi- ous, and the ultimate tensile strength and the elongation of A356 aluminum alloy automobile brake calipers are higher. When the forging deformation amount reaches more than 11.1%, the shrinkage cracks within the automobile brake calipers can be closed and the dendrite grains are broken to fine grains due to the severe plastic deformation. When the forging deformation amount is 17.3%, the ultimate tensile strength and the elongation of A356 automobile brake calipers are 315.1MPa and 6.4%, which are improved by 18.6% and 30.6% compared with those of A356 aluminum alloy automobile brake calipers without forging.