为了避免和减小镁铝尖晶石在研磨工艺中产生的亚表面损伤, 研究了合理控制磨削参数, 实现镁铝尖晶石塑性域磨削的方法。分析了镁铝尖晶石的脆塑转变机理, 采用不同尺寸规格的金刚石砂轮磨粒和改变砂轮进给量等参数进行了大量实验, 探索了镁铝尖晶石的塑性磨削条件及影响因素, 实现了镁铝尖晶石的塑性域高精度磨削。采用VG401MKII型超精密磨床和3000#金刚石砂轮, 设定砂轮速度为20 m/s, 工件速度为0.3 m/s, 进给量为0.5~3 μm/r进行了磨削实验。结果显示: 当金刚石砂轮磨粒的平均尺寸小于8 μm时可以实现镁铝尖晶石的塑性磨削, 其表面粗糙度Ra可以达到2.291 nm, 透光率可提高17%。研究结果表明, 砂轮的平均磨粒尺寸和砂轮进给量对镁铝尖晶石材料的表面加工质量影响很大, 该结果为研究磨削高质量镁铝尖晶石表面提供了依据。

To avoid and reduce the subsurface damage generated in grinding process of MgAl2O4 spinel, a ductile grinding method of MgAl2O4 spinel by reasonably controlling grinding parameters was proposed. The brittle-ductile transition mechanism for the MgAl2O4 spinel was analyzed , and a lots of experiments were performed by using abrasive particles of diamond wheel with different dimensions and changing the load of grinding wheel and other parameters. The ductile grinding conditions and effect factors of the MgAl2O4 spinel were explored and a higher precision ductile grinding for the MgAl2O4 spinel was implemented. By adopting the VG401MKII precision grinder with 3000# diamond wheel, a grinding experiment was carried out under the condition of a wheel speed of 20 μm,a workpiece speed of 0.3 m/s and the feed load of 0.5-3 μm/r. The experimental results show that the ductile grinding of MgAl2O4 spinel could be achieved when the average dimension of abrasive particles for the diamond wheel is less than 8 μm, its surface roughness could reach Ra 2.291 nm, and light transmittance can be improved by 17%. The research results show that the average dimension of abrasive particles for the grinding wheel and the feed load of grinding wheel have great influence on the quality of finished surfaces. It provides references for the study of grinding high-quality surfaces of MgAl2O4spinel.