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超塑性非球面自由胀形的测量宋玉泉1,马品奎1,管志平1(1.吉林省长春市吉林大学超塑性与塑性研究所)摘 要:超塑性胀形是成形薄壁壳形件的重要技术,已经在航空技术领域占有重要地位.由于超塑性自由胀形是建立超塑胀形力学解析理论的重要依据,又是超塑胀形成形的必经阶段,而超塑自由胀形的轮廓曲面为轴对称旋转曲面,本文针对精确测量轴对称旋转曲面的几何参数尚存在的一些问题,提出了测量方法及基本原理,介绍了基于单目成像的图像采集系统及摄像机参数的标定方法,并对旋转体试件的成像测量进行分析,给出了误差补偿公式;对于实验中极点高度......
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and development direction of superplastic magnesium alloys CHEN Zhen-hua, LIU Jun-wei, CHEN Ding, YAN Hong-ge (School of Materials Science and Engineering, Hunan University, Changsha 410082, China) Abstract: The active energy and constitutive equations of magnesium alloys formed under different conditions were reviewed. The superplastic characteristics of coarse and fine-grained magnesium alloys were......
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不锈钢带拉矫过程变形行为的数值模拟研究孙朝阳1,张栋1,张清东1,李实2,蔡永跃2(1.北京市北京科技大学机械工程学院2.宁波宝新不锈钢有限公司,浙江宁波 315807)摘 要:建立了不锈钢拉伸弯曲矫直过程的有限元仿真模型,该模型针对不锈钢拉矫机辊组配置和旋转压下的特点,采用了窄条三维壳单元对带钢进行特征建模.为提高计算效率,带钢网格进行了局部细化.对304不锈钢典型规格带钢拉矫过程进行模拟,伸长率计算值与实测值吻合较好.对带钢拉矫过程特征位置点经过各辊组的应力应变分析表明:带钢伸长率主要由1号弯曲辊组提供,而......
. The results of tensile tests showed that the Mg-4Li-3(Al-Si) alloy exhibited the highest ultimate tensile strength (UTS) of 249 MPa but the lowest elongation of 6.3%. The Mg-12Li-3(Al-Si) alloy had the highest elongation of 26% but the lowest UTS of 173 MPa. The different mechanical properties were attributed to the different crystal structures of the three alloys and the precipitate with different......