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使用低压气吹超塑性金属片形成复杂轮廓已广泛应用于航空及汽车工业中,其普遍定义为超塑成形法(SPF)。超塑成形的优点包括低成本及模具便宜易制并且成品具有低残留应力。另一方面,超塑成形的产品易造成厚度分布不均匀。然而,也有降低此缺点的技术。采用超塑性AA5083板材以低压气吹使V型板材成形至深凹不平的V型槽。先使用机械辅助热弯曲使板材成V型后再进行气吹。在热弯曲阶段,如果弯曲的深度超过一定水平将导致挫曲。挫曲和几何轮廓将影响所形成产品厚度分布以及皱褶发生位置,但是将获得更好的厚度分布。皱褶可经由规划以达到更好的均匀厚度分布,但皱褶位置需要产生于半成品的修剪线外。因此,控制热弯曲阶段以获得一个合适的预成形板材得以气吹成形是至关重要的。
The use of low pressure gas blowing superplastic sheet metal to form a complex profile has been widely used in the aviation and automotive industries, which is generally defined as superplastic forming (SPF). The advantages of superplastic forming include low cost and easy to manufacture molds and finished products with low residual stress. On the other hand, superplastic molded products easily lead to uneven thickness distribution. However, there are techniques to reduce this disadvantage. The superplastic AA5083 sheet is used to form the V-shaped plate into a concave V-shaped groove by low-pressure gas blowing. First use the mechanical auxiliary heat bending so that the plate into a V-type gas blowing afterwards. In the hot bending phase, if the bending depth exceeds a certain level will lead to frustration. Setbacks and geometric contours will affect the thickness distribution of the resulting product as well as the location of the wrinkles, but will result in a better thickness profile. The wrinkles can be laid out to achieve a better uniform thickness distribution, but the wrinkle position needs to be created outside the trimmed part of the semifinished product. Therefore, it is of crucial importance to control the hot bending stage to obtain a suitable pre-formed sheet for gas blow molding.