Filling and solidification in low pressure casting aluminum alloy automotive seat frame have been simulated by FEM(finite element method) combining with orthogonal testing to understand effects of processing parameters on shrinkage porosity(hole),filling and solidification.The results showed that the minimum shrinkage porosity(hole) rate in the low pressure casting aluminum alloy automotive seat frame has been observed with desirable appearance quality when filling temperature 720℃ with filling pressure rate of 920Pa/s and mold preheating of 380℃.

The effect of mixed RE addition on microstructure and mechanical property was studied when the addition(wt.%) varying from 0,0.4,0.8 to 1.0.The results show that the addition of mixed RE has a great influence on properties and microstructure of Al-Cu-Mn alloy.With the increase of the addition of mixed RE,the tensile strength of the alloy increases,and has the peak when mixed RE is 0.4%,then it decreases when the addition exceeds 0.4%.With the increase of the addition of mixed RE,the microhardness of alloy matrix decreases quickly.

After analysing the original steel design of automotive seat back frame,three different sectional shapes of the seat back steel pipes are designed based on mechanics of materials,and numerical calculations are carried out with finite element software HyperWorks.Topology optimization design of aluminum seat back is carried out using density method.The result shows that the linear static strength of elliptic section for steel tube is more than that of the round section with same area,topology optimization is a kind of effective method of structure design.The weight of aluminium alloy seat back reduces 16.5%,realizing the purpose of automotive seat lightweight from two aspects of structure and material.

通过对比试验发现:混合稀土含量对ZL201组织和性能都有很大的影响,当稀土含量在0.6%左右时,合金显微组织变得非常细小,硬度也达到很高的数值;但超过这个含量后,合金晶粒开始变粗,硬度也随之降低。最后,利用动力学的相关原理,证明了稀土元素发挥变质作用时最佳含量的存在。

In order to study the effect of pressure parameters on porosity in the casting,the low pressure casting process of the aluminum automotive seat frame has been simulated by finite element simulate software and single-factor experiment.According to the simulation results,the higher filling pressure and the rate of increase pressure could improve the ability of filling for thin-wall casting;for particular thin-wall castings,there was a critical pressurization rate to make shrinkage porosity rate minimum.In addition,with the improvement of pressure,shrinkage porosity rate reduced.

A compound die for blanking and drawing a filter box was designed based on analysis of its stamping process.The new die has a box-shaped structure instead of original flanging structure.The improvement of the box's structure and stamping process can obviously increase the static strength of the product's structure.

一、引言汽车座椅靠背呈现出不规则的曲面结构,利用传统的绘图工具很难达到设计的准确性要求,且费时、费力.在静强度分析方面,手工计算只适用于结构简单、形状规则的零部件,而对于座椅靠背等结构复杂且形状不规则的零部件,则需要借助有限元分析的方法进行模拟计算.本文利用NX软件的三维建模功能可以将设计的三维实体零件生动地反映在计算机屏幕上,设计者可以形象地观察到所设计的图形是否能够满足产品的具体要求,从而可以做到适时修改.利用Hyperworks软件对新设计的汽车座椅进行静强度及刚度分析,可以直观得知设计中的薄弱点,对结构进行修改,直至符合国家相关法规的要求.

<正>传统的客车座椅骨架多以冲压钢板(管)焊接而成,因此往往重量偏高。而铝合金及其加工件具有一系列优良特性,诸如密度小、比强度和比刚度高、弹性好、抗冲击性能优良及较高回收再生性等。若能将其应用于汽车座椅骨架,那么减重效果是很明显的,尤其对于商务车和大型客车(40～60座)。笔者在详细比较和研究了各种轻合金特性、经济性及生产制造工艺的基

In order to solve the problem of complex structure and complicated manufacturing process and achieve the target of lightweight,choosing a fixed steel armrest of a bus as prototype,the aluminum alloy material ZL104 was selected to replace the original steel material and the structure optimization was achieved.The mold for die casting was designed by Pro/E software.The maximum cross-section was chosen as the parting plate and a mechanism of side pulling of core was chosen.Overflow tanks were set up at the end of the filling molten metal.The design can provid certain reference for industry practices.

Filling and solidification in low pressure casting aluminum alloy automobile seat frame were simulated by FEM(finite element method) combining with orthogonal testing to understand effects of processing parameters on shrinkage porosity(hole) ,filling and solidification. The results show that the minimum shrinkage porosity(hole) rate in the low pressure casting aluminum alloy seat frame can be observed with desirable appearance quality when filling time is 1.5s with holding-pressure of 7kPa and holding-pressure time of 100s.

It was found through the contrast experiment that the content of mixed RE had a great influence on the properties and microstructure of ZL201.When the contents of mixed RE reach 0.6%,the microstructure of the alloy changed extremely tiny and the hardness also achieves a very high value.But surpassed this contents,the crystal grain of alloy became coarsen,and the hardness reduced along with.The aging treatment had a certain degree influence on the properties and microstructure of the metal mould casting,but the influence was insignificancy.

The effect of solid solution treatment time on six kinds of Mg alloyed ZL201 was analyzed by mechanical property test and optical microscope.The results show that the ZL201 alloy with 1.5% to 1.7% of Mg could gain small and more uniform distributed fine microstructures.After 535 ℃ × 8h and 535 ℃ × 12 h solution treatment,the hardness of the six kinds of components was slightly lower,and the alloys got strengthened by solid solution treatment at 535 ℃ × 4 h.The alloy containing 1.7%Mg got the best effect of solution treatment.The result provides the reference for parameter selection and further optimization of heat-treatment process of this alloy.