Experimental and simulation study of material removal behavior in ultra-precision turning of magnesium aluminate spinel (MgAl2O4)
Experimental and simulation study of material removal behavior in ultra-precision turning of magnesium aluminate spinel (MgAl2O4)
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DOI：
10.1016/j.jmapro.2022.07.044
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发表时间：
2022-10
影响因子：
6.2
通讯作者：
H. Geng;Dongbo Wu;Haibo Wang
中科院分区：
文献类型：
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作者：
H. Geng;Dongbo Wu;Haibo Wang
超精密车削是高效率、低损伤加工镁铝尖晶石的有效工艺方法之一。通过实验和模拟研究了车削参数和材料微观结构对铝酸镁尖晶石（MgAl2O4）超精密车削材料去除行为的影响。开发了有限元法 (FEM) 模型来了解刀具前角、切削深度和切削速度对加工表面的影响。通过微槽切削试验对模拟结果进行了实验验证。负前角刀具可以提高尖晶石的塑性，增加韧脆转变深度。然而，负前刀面产生的压应力场带来更严重损坏的风险。减少切削深度可以抑制裂纹。在一定范围内提高切削速度不会恶化表面质量，并且可以提高材料去除率。尖晶石晶粒在微观尺度上的各向异性对材料行为有很大影响，导致表面形貌不均匀。为了获得高质量的加工表面，未变形切屑厚度必须小于最脆性晶粒的韧脆转变深度。实验和仿真结果表明，通过超精密车削实现光滑表面的车削参数的优化组合，以实现多晶硬脆材料的低损伤超精密车削。
Ultra-precision turning is one of the effective process methods to machine magnesium aluminate spinel with high efficiency and low damage. The influences of turning parameters and material microstructure on material removal behavior in ultra-precision turning of magnesium aluminate spinel (MgAl2O4) were investigated through experiment and simulation. A finite element method (FEM) model was developed to understand the effect of tool rake angle, cutting depth and cutting speed on the machined surface. Simulation results were verified experimentally by micro-groove cutting test. A negative rake angle tool can improve the plasticity of spinel and increase the ductile-brittle transition depth. However, the compressive stress field generated by the negative rake face brings the risk of more serious damage. Reducing cutting depth can suppress cracks. Elevating the cutting speed within a certain range does not deteriorate the surface quality and can increase the material removal rate. The anisotropy of spinel grains at micro-scale is of a great influence on the material behavior, leading to a non-uniform surface topography. In order to obtain a high-quality machined surface, the undeformed chip thickness must be smaller than the ductile-brittle transition depth of the most brittle grain. Experimental and simulation results suggest an optimized combination of turning parameters for a smooth surface by ultra-precision turning to achieve low-damage ultra-precision turning of polycrystalline hard and brittle materials.