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采用强流脉冲电子束(HCPEB)技术对真空感应熔炼法制备的Cu-25Cr合金进行表面改性处理,所选用的脉冲次数范围为1~100。采用扫描电镜和X射线衍射技术对HCPEB处理前后样品表面的形貌和显微组织进行研究。结果显示,当脉冲次数增加到10次后,样品表面形貌会发生显著变化。在HCPEB处理过程中所产生的动态温度场使Cu-25Cr合金表面形成典型的熔坑组织。同时,该过程中所累积的准静态热应力场导致样品表面出现微裂纹,其数量随脉冲次数的增加而增大。另外,HCPEB处理还使Cu-25Cr合金表面发生液相分离现象,产生大量细小的Cr球。在上述特征组织的综合作用下,样品表面的粗糙度随脉冲次数的增加而增长。
The surface modification of Cu-25Cr alloy prepared by vacuum induction melting was performed by using HCPEB technique. The pulse number range of 1-100 was selected. The morphology and microstructure of the samples before and after HCPEB treatment were studied by scanning electron microscopy and X-ray diffraction. The results show that when the pulse number increased to 10 times, the sample surface morphology will change significantly. The dynamic temperature field generated during the HCPEB treatment formed a typical crater on the Cu-25Cr alloy surface. At the same time, the quasi-static thermal stress field accumulated in this process leads to the appearance of micro-cracks on the sample surface. The number increases with the increase of the number of pulses. In addition, HCPEB treatment also causes the Cu-25Cr alloy surface liquid phase separation phenomenon, resulting in a large number of small Cr ball. Under the combined effect of the above characteristic tissues, the roughness of the sample surface increases with the increase of the number of pulses.