The automobile suspension parts of a high strength 6xxx aluminum alloy were produced using a novel technique known as near net shape casting for forging stock preparation. Based on the outline dimension of the forging...The automobile suspension parts of a high strength 6xxx aluminum alloy were produced using a novel technique known as near net shape casting for forging stock preparation. Based on the outline dimension of the forging stock, the shape of the ingot was designed as the near net shape and its casting process was studied by the numerical simulation and experimental investigation. The results show that the shrinkage of the ingot was highly correlated to its shape parameters and could be successfully forecast by the stimulation model. The casting parameters of the near net shape ingot were optimized and the near net shape 6xxx aluminum alloy ingots free of defects were cast in the laboratory. In order to obtain high performance forged suspension parts, the hot compression tests of the ingot were carried out. The results show that the subgrain fraction of the forged ingot was strongly affected by Zener-Hollomon parameters （Z parameters）. The intermediate Z parameters, 1.09×10^16 s^-1, will contribute to the larger number fraction of subgrains inside the forged ingot, which contributes to the high performance of the forged products.展开更多
采用光学显微镜、扫描电镜、能谱分析和力学性能测试等手段,对油气滑半连续铸造φ254 mm 6061铝合金圆棒的均匀化态微观组织和后续锻造轮毂过程进行研究。结果表明,铸锭偏析层中含Fe相的数量、大小和形貌,与锻造成形、裂纹形成扩展和轮...采用光学显微镜、扫描电镜、能谱分析和力学性能测试等手段,对油气滑半连续铸造φ254 mm 6061铝合金圆棒的均匀化态微观组织和后续锻造轮毂过程进行研究。结果表明,铸锭偏析层中含Fe相的数量、大小和形貌,与锻造成形、裂纹形成扩展和轮毂力学性能有着直接的关系。当Fe含量由0.32%降低到0.22%,均匀化温度由550℃提高到约570℃,保温13 h时,铸锭R/2处均匀化态组织中Al_(2)Cu相完全回溶、MgSi相少量残留、AlFeSi相更断续弥散,β-AlFeSi相的面积分数由1.08%减少到0.73%,MgSi相的面积分数由1.11%减少到0.67%;同时,偏析层区域的均匀化组织中β-AlFeSi相和MgSi相的富集量明显减少,β-AlFeSi相的最大尺寸由60.2μm减小到29.9μm,面积分数由1.57%减少到0.89%,减少变形过程中粗大脆硬β-AlFeSi相周围区域的应力集中。此时,锻造轮毂成形性最好,有效的抑制了锻造裂纹的产生,轮毂本体的抗拉强度由322 MPa提高到378 MPa,伸长率由10.2%提高到12.2%。展开更多
基金National Natural Science Foundation of China(No.505601003)Natural Science Foundation of Liaoning Province(No.20052176)+1 种基金The Pro-ject-sponsored by SRF for ROCS,SEM([2006]331)Program of New Century Excellent Talents in University(NCET-07-0137)
文摘The automobile suspension parts of a high strength 6xxx aluminum alloy were produced using a novel technique known as near net shape casting for forging stock preparation. Based on the outline dimension of the forging stock, the shape of the ingot was designed as the near net shape and its casting process was studied by the numerical simulation and experimental investigation. The results show that the shrinkage of the ingot was highly correlated to its shape parameters and could be successfully forecast by the stimulation model. The casting parameters of the near net shape ingot were optimized and the near net shape 6xxx aluminum alloy ingots free of defects were cast in the laboratory. In order to obtain high performance forged suspension parts, the hot compression tests of the ingot were carried out. The results show that the subgrain fraction of the forged ingot was strongly affected by Zener-Hollomon parameters （Z parameters）. The intermediate Z parameters, 1.09×10^16 s^-1, will contribute to the larger number fraction of subgrains inside the forged ingot, which contributes to the high performance of the forged products.
