为了研究固液两相磨粒流对伺服阀阀芯喷嘴的研抛性能, 从冲蚀磨损的角度对比分析了不同磨粒硬度下的磨粒流研抛效果。利用计算流体力学方法, 求解分析了磨粒流研抛伺服阀阀芯喷嘴时流场中的冲蚀磨损特性, 采用电子显微镜以及扫描电镜仪检测伺服阀阀芯喷嘴零件经磨粒流研抛前后的表面粗糙度和表面形貌。实验结果表明: 采用碳化硅磨粒和白刚玉磨粒加工后的伺服阀阀芯喷嘴主干通道、交叉孔以及小孔区域的粗糙度分别由1.1 μm、0.823 μm、0.743 μm降低为0.735 μm、0.721 μm、0.571 μm和1 μm、0.747 μm、0.696 μm。在本试验中碳化硅磨粒的加工效果优于白刚玉磨粒, 即具有高磨粒硬度的磨粒研抛效果好。检测结果显示, 磨粒流研抛技术可有效改善伺服阀阀芯喷嘴的表面质量; 提高磨粒硬度可提高磨粒流的研抛效果; 伺服阀阀芯喷嘴的交叉孔以及小孔区域的表面质量要高于主干通道的表面质量。

In order to study the polishing performance of the solid-liquid two-phase abrasive flow on the servo valve core nozzle, polishing effect of abrasive flow on condition of different abrasive particle hardnesses was contrasted and analyzed in perspective of erosive wear. Erosive wear features in flow field was analyzed by computational fluid mechanics when abrasive flow polishes servo valve core nozzle, and surface roughness and surface morphology of servo valve core nozzle before and after polished by abrasive flow were detected by electron microscope and scanning electron microscope. Experimental result indicates that the surface roughness of main channel, cross hole and microhole of servo valve core nozzle respectively reduces from 1.1 μm, 0.823 μm, 0.743 μm to 0.735 μm, 0.721 μm, 0.571 μm after processing of silicon carbide abrasive particles, and roughness reduces to 1 μm, 0.747 μm, 0.696 μm respectively after processing of white alundum abrasive particles. Process effect of abrasive particles of silicon carbide is better than that of white alundum in this test, namely that polishing effect of abrasive particles of high hardness is good. Detection result indicates that polishing technology of abrasive flow can effectively improve surface quality of servo valve core nozzle and polishing effect of abrasive flow can be improved via increasing hardness of abrasive particles, and surface quality of cross hole and microhole is better than that of main passage.