双锥薄壁7A04铝合金零件热塑性成形模拟和热处理工艺研究

发布时间：2018-04-13 02:37

  本文选题：7A04铝合金 + 挤压　； 参考：《南京理工大学》2017年硕士论文

【摘要】：本文以双锥薄壁7A04铝合金零件为主要研究对象,在预先确定挤压成形方案、坯料类型和工艺参数范围的基础上,利用有限元模拟软件Deform-3D分析双锥薄壁零件成形过程中内部金属流动规律、载荷变化情况、各种场量分布等,同时研究变形温度、坯料形状尺寸、变形速度、润滑条件等因素对成形结果的影响规律,确定最佳的挤压工艺参数。参照YST 591-2006变形铝及铝合金热处理规范,根据零件预期达到的力学性能要求,确定热处理工艺参数范围。对挤压好的零件进行不同方式固溶处理和不同工艺时效处理,通过观察金相组织、进行室温拉伸试验比较力学性能,确定最合适的热处理工艺参数。结果表明:相比于柱状坯料和带孔板材坯料,管状坯料成形时所需的载荷最小,且成形后零件整体的等效应变最小,变形最均匀,最终确定选用尺寸为内径31mm,厚度10mm,高度76.5mm的管状坯料。综合对所有模拟结果的分析和比较,最终确定挤压温度为485℃,挤压速度分为两段,前120mm行程的挤压速度为20mm/s,之后行程的挤压速度为5mm/s。固溶处理可以使7A04铝合金基体中的第二相溶解更充分,在随后的时效过程中,合金通过沉淀强化使强度得到大幅度提高。固溶温度和时效温度对合金强度的影响较大,随着固溶温度升高,基体中的第二相数量变少,颗粒变小,合金过饱和程度提高,但晶粒发生不同程度的长大。经过综合对比,合金经过460℃C,1h+480℃C,1h双级固溶处理和120℃C,16h时效后,获得的性能最好,抗拉强度达到最大值659.6MPa,此时Rp0.2=608.8MPa,A=12.79%。
[Abstract]:In this paper, the two-cone thin-walled 7A04 aluminum alloy parts are taken as the main research object, on the basis of the pre-determination of extrusion scheme, blank type and process parameter range, the main research object is the two-cone thin-walled 7A04 aluminum alloy parts.The finite element simulation software Deform-3D is used to analyze the metal flow law, load change, distribution of various fields and so on in the forming process of two-cone thin-walled parts. At the same time, the deformation temperature, blank shape and size, deformation speed, etc are studied.The influence of lubrication conditions on the forming results was studied, and the optimum extrusion parameters were determined.According to the heat treatment specifications of YST 591-2006 deformed aluminum and aluminium alloys, the range of heat treatment process parameters is determined according to the mechanical properties of the parts expected to be achieved.The extruded parts were treated with different methods of solution treatment and different aging processes. By observing the metallographic structure and comparing the mechanical properties with tensile tests at room temperature, the most suitable heat treatment parameters were determined.The results show that, compared with the cylindrical blank and the blank with holes, the tubular blank needs the least load, and the equivalent strain of the whole part after forming is the least, and the deformation is the most uniform.The final size is 31 mm, thickness 10 mm, height 76.5mm tube blank.According to the analysis and comparison of all the simulation results, the extrusion temperature is 485 鈩，

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