钛及钛合金X射线应力测试参数的选择

Selection method of X-ray diffraction stress measurement parameters for titanium and titanium alloy

针对钛及钛合金X射线应力测试中衍射峰强度低、峰形差、测试结果波动范围大和准确度低等问题,通过对标准零应力试样和标准应力试样的X射线应力测试,研究了钛及钛合金X射线应力测试中准直器直径、计数时间和计数次数变化对衍射峰强度、净峰强度、半高宽、应力测试结果的影响规律,在此基础上确定了钛及钛合金X射线应力测试参数的选择方法,并对钛合金电子束焊接头的残余应力进行了测试.结果表明,随着准直器直径增大和计数时间增长,衍射峰强度增大,衍射峰形改善,测试结果准确性提高;随着计数次数增加,衍射峰形改善,测试结果准确性提高;所确定的测试参数对钛合金电子束焊接头残余应力测试的结果满足相关标准要求.

Considering the low intensity of diffraction peak,bad diffraction profile,wide fluctuation range and low accuracy of the stress measurement results for titanium and titanium alloy,the effects of aperture diameter,exposure time,and exposure number on the intensity of X-ray diffraction peak,net intensity,full width at half maximum,and the stress measurement results were investigated through the X-ray stress measurement of free stress standard sample and high stress standard sample.On this basis,the selection method of X-ray diffraction stress measurement parameters for titanium and titanium alloy was decided and used in measuring the residual stresses in TC4 welded joint.Results show that with the increase of aperture diameter and exposure time,the intensity of X-ray diffraction peak increases,both the diffraction profile and the accuracy of the test results are improved.What's more,with the increase of exposure number,the diffraction profile and the accuracy of the test results are also improved.The measurement results of residual stresses in TC4 welded joint meet the requirements of the related standards.