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采用霍普金森压杆(SHPB)对AZ31镁合金进行了高速切削实验。实验采用两把YT15硬质合金刀具,并对称地固定在实验装置上。在实验过程中,实验样品固定在样品台上,用霍普金森压杆高速冲击样品台,带动样品的高速移动,从而实现高速切削,实验气压分别为0.25,0.30,0.35 MPa,其对应的切削速度分别约为14,17,20 m·s~(-1)。切削完成后,收集相应切削速度下的切屑,然后进行镶样、抛磨,最后利用金相显微镜(OM)和扫描电子显微镜(SEM)研究了切削速度对AZ31镁合金切屑形貌的影响。结果表明:随着切削速度的增加,切屑的锯齿形态逐渐变得规则,锯齿化程度、锯齿化频率相应增加,齿距减小;当切削速度增大到一定程度时,切屑齿面出现了微裂纹,同时伴随着锯齿齿形整体偏移的情形,而锯齿化程度、锯齿化频率、齿距等变化都趋于平缓。
High-speed cutting experiments on AZ31 magnesium alloy were carried out with Hopkinson pressure bar (SHPB). Experiments using two YT15 carbide tools, and symmetrically fixed in the experimental device. During the experiment, the experimental sample is fixed on the sample stage, and the Hopkinson pressure bar is used to impact the sample stage at high speed to drive the sample to move at high speed, so that the high-speed cutting can be realized. The experimental pressures are 0.25, 0.30 and 0.35 MPa respectively, The speed is about 14,17,20 m · s ~ (-1) respectively. After cutting, the chips at the corresponding cutting speed were collected, then set up and polished. Finally, the effect of cutting speed on the chip morphology of AZ31 magnesium alloy was studied by OM and SEM. The results show that with the increase of cutting speed, the sawtooth shape of chip gradually becomes regular, the degree of sawing and the frequency of sawing increase correspondingly, and the pitch decreases. When the cutting speed increases to a certain extent, Cracks, accompanied by the overall shift in the case of serrated teeth, and sawing degree, sawtooth frequency, pitch and other changes tend to be gentle.