铝合金薄壁管热态内压成形的变形控制

On the Deformation Control during IHPF of Thin-walled Aluminum Alloy Tube at Elevated Temperature

薄壁管材热态内压成形时,管材内部各处受到均匀内压的作用,但是由于管材各处的温度和边界条件不同,所以将产生复杂的变形过程。讨论热态内压成形时影响管材变形的主要因素,揭示管材热态内压成形时产生不均匀变形的主要原因。在此基础上,结合实例说明如何从控制温度分布和模具约束条件2个方面来控制管材的变形。采用不均匀温度分布,可改变各区域材料的变形抗力和摩擦状况,提高管材零件的壁厚均匀性;采用局部快速加热,可实现长管状零件的局部成形而无需大尺寸的模具;采用局部模具约束,可改变不同区域变形的先后顺序、有效控制变形的不均匀性,从而提高管材的成形性能。

The inner of the thin-walled tube is subjected uniform internal pressure during hot pressure forming. Be- cause of the difference of temperature and boundary conditions for different part of the tube, the tube will undergo complex deformation process. The paper discussed the main factors affecting the tube deformation in hot pressure forming, and the main reasons for the uneven deformation have been obtained. On this basis, how to control the tube deformation through controlling temperature distribution and die constraint was illustrated by way of example. The use of non-uniform tempera- ture distribution can alter the regional deformation resistance and friction conditions, also improve the uniformity of the tube thickness. The use of local rapid heating can achieve the local forming of long tubular parts without large dies. The use of local die constrains can change the order of the deformation in different areas and control the non-uniformity of deformation effectively, therefore can improve the forming performance of the tube.