铝合金变速箱箱体双重挤压铸造工艺与性能研究
发布时间：2018-10-23 18:27
【摘要】：变速箱箱体作为车辆传动系统的重要零件,以铝合金代替铸铁、以挤压铸造代替砂型铸造,不仅能够降低工程车辆的整体重量,还可以改善箱体的散热性能,提高生产效率。但是,对于箱体局部部位较厚,铸件内部容易产生缩松、缩孔缺陷,本文使用双重挤压铸造工艺,对厚大部位采用局部加压的方式,提高铸件质量。本文通过数值模拟、生产试验和X射线检测、金相组织分析、力学性能分析、断口形貌分析等方法,研究了不同工艺参数对变速箱箱体质量与性能的影响,并进行了局部加压试验,主要研究工作和成果如下:(1)根据变速箱箱体的结构特点,对箱体的双重挤压铸造工艺进行了分析,并设计了变速箱箱体双重挤压铸造模具。(2)使用ProCAST模拟软件,以浇注温度、压射比压、模具预热温度三个因素进行了三因素、三水平正交试验。模拟结果表明:浇注温度为680℃,压射比压为120MPa,模具预热温度为200℃时,铸件本体的缩松、缩孔最小,初步确定了挤压铸造工艺参数。(3)在初步确定的工艺参数下进行了充型、凝固过程仿真和缺陷预测,结果表明,充型过程无明显的卷气、紊流等现象;凝固过程可以实现定向凝固,有利于压力的传递;未出现有害的铸造应力,铸件本体的缩松、缩孔仅出现在有待局部加压部位,为局部加压工艺的实现奠定基础。(4)设计了六组工艺参数进行挤压铸造试验,从力学性能、微观组织和断口形貌方面,进行了研究分析,并对最佳的一组工艺参数进行局部加压。结果表明,最佳工艺参数为:浇注温度为680℃,压射比压为120MPa,模具预热温度为200℃,局部加压力为135MPa,加压延时选用26~30s中的5个值,以单一变量法确定最佳加压延时为27s。在该工艺参数下,铸件晶粒细小、圆整且分布均匀,经过T6热处理的试样抗拉强度为327MPa,延伸率为3.5%,铸件内部无铸造缺陷。
[Abstract]:As an important part of vehicle transmission system, gearbox box can not only reduce the whole weight of engineering vehicle, but also improve the heat dissipation performance and production efficiency by aluminum alloy instead of cast iron and squeeze casting instead of sand mold casting. However, the local part of the box is thicker and the inner part of the casting is easy to produce shrinkage and hole defects. In this paper, the double squeeze casting process is used to improve the casting quality by means of local pressure on the thick and large parts. In this paper, the effects of different technological parameters on the quality and performance of the gearbox are studied by means of numerical simulation, production test and X-ray examination, metallographic analysis, mechanical property analysis and fracture morphology analysis. The main research work and results are as follows: (1) according to the structural characteristics of the gearbox box, the double squeeze casting process of the box body is analyzed. The double squeeze casting die of the gearbox box was designed. (2) three factors, three levels orthogonal test, were carried out by using ProCAST simulation software, including pouring temperature, injection specific pressure and die preheating temperature. The simulation results show that when the pouring temperature is 680 鈩，
本文编号：2290105
[Abstract]:As an important part of vehicle transmission system, gearbox box can not only reduce the whole weight of engineering vehicle, but also improve the heat dissipation performance and production efficiency by aluminum alloy instead of cast iron and squeeze casting instead of sand mold casting. However, the local part of the box is thicker and the inner part of the casting is easy to produce shrinkage and hole defects. In this paper, the double squeeze casting process is used to improve the casting quality by means of local pressure on the thick and large parts. In this paper, the effects of different technological parameters on the quality and performance of the gearbox are studied by means of numerical simulation, production test and X-ray examination, metallographic analysis, mechanical property analysis and fracture morphology analysis. The main research work and results are as follows: (1) according to the structural characteristics of the gearbox box, the double squeeze casting process of the box body is analyzed. The double squeeze casting die of the gearbox box was designed. (2) three factors, three levels orthogonal test, were carried out by using ProCAST simulation software, including pouring temperature, injection specific pressure and die preheating temperature. The simulation results show that when the pouring temperature is 680 鈩，
本文编号：2290105
本文链接：https://www.wllwen.com/kejilunwen/qiche/2290105.html
