7075-O铝合金板料的摩擦搅拌渐进成形：成形零件性能的实验研究

Friction Stir Incremental Forming of AA7075-O Sheets: Experimental Investigations on Performance Evaluation of Formed Parts

摘要:

本文中,用不同的主轴转速来成形两种典型零件,研究了摩擦搅拌渐进成形零件的综合性能：成形性,表面质量,拉伸性能,显微硬度和壁厚分布。试验结果表明,板料的成形性随着转速增加而呈现增强趋势；接触面的表面粗糙度在水平和竖直方向表现出不同的变化趋势；非接触面的表面质量几乎不受转速影响；相比原板料,成形零件的拉伸性能和显微硬度明显增强,但转转速超过3000 rpm后,硬度值开始逐步下降；在高转速下成形零件的壁厚分布略微优于低转速下的成形零件。总体上,除了力学性能,高转速下成形零件的综合性能比低转速下的成形零件好。

Abstract:

A comprehensive performance of formed parts is studied in Friction Stir Incremental Forming (FSIF). In this paper, various tool rotation speeds are set to form two typical parts (truncated funnel and pyramid frustum). Specifically, formability, surface quality, tensile strength, micro-hardness and thickness distribution are investigated and analyzed. Experimental results show that the formability generally increases as tool rotation speeds increase. On the contact surface, variation trends of the surface roughness are different in horizontal direction (parallel to tool path) and vertical direction (perpendicular to tool path). However, the surface roughness on the non-contact surface is almost not affected by tool rotation speed. Furthermore, mechanical properties including tensile strength and surface micro-hardness in formed parts are obviously enhanced compared to the initial sheet, of which the hardness values begin to fall down gradually after rotation speed reaches 3000 rpm. As for thickness measurement, more uniform thickness distribution of formed parts can be obtained at relative high tool rotation speeds. In general, parts formed at high rotation speed have a better comprehensive performance except the mechanical property.