拉紧条件下铝合金铣削残余应力的试验研究

以铝合金为研究对象,提出将拉紧装夹应用到铣削加工中,以便对加工后工件表层的应力状态进行控制,改善零件的疲劳性能。本文设计了机械式单向拉紧夹具用于铣削试验。通过试验,得出了预应力、工件厚度以及加工参数等对表面残余应力的影响趋势。研究表明,拉紧条件下铣削可以实现对工件表面残余应力的控制,从而获得理想的残余压应力,对改善零件的疲劳性能极其有益。在本试验条件下,获得的工件表面残余应力均为压应力,最大可达-250 M Pa。

Experiment on Residual Stress of Milling-Machined Aluminum Alloy Under Stretched Fixation

The stretched fixation is used in the milling operation to control the residual stresses on the machined work surface and to improve the fatigue performance of the work.One-dimensional mechanical stretched fixture is designed and used in milling experiments.By experiments,the effects of the pre-stretched force,the work thickness and milling parameters on residual stresses on the milled surface are obtained.It is shown that residual stresses on the milled surface can be controlled to a compressive level by the milling under the stretched fixation.It can improve the fatigue performance of the work.Under experimental conditions,residual stresses on the work surface are all compressive and the highest one reaches to-250 MPa.