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运用ABAQUS有限元软件建立了γ-TiAl金属间化合物铣削加工的细观模型,分析了不同材料模型的加工表面形貌及边缘断裂形成机理。结果表明,由于片层之间的材料特性不同,加工过程中片层与片层之间更容易出现裂纹或凹坑。同时,由于其较低的延展性,γ-TiAl金属间化合物加工出口处形成较大的负剪切平面,从而导致边缘断裂。通过与实验结果比较,发现γ-TiAl金属间化合物铣削加工表面粗糙度和边缘断口尺寸均小于由正六边形片层细观模型所得的模拟值,且略高于由矩形片层细观模型所得的模拟值。同时,加工表面粗糙度和边缘断口尺寸随切削深度的增加而逐渐增大,而切削速率的影响较小。因此,为了得到更好的加工表面质量,γ-TiAl金属间化合物加工过程中应尽可能地采用较高的切削速率,而不是切削深度。
The meso-scale model of γ-TiAl intermetallic compound milling was established by ABAQUS finite element software. The machined surface morphology and the formation mechanism of edge fracture of different material models were analyzed. The results show that due to the different material characteristics between the layers, cracks or pits are more likely to occur between the layers during the processing. At the same time, due to its low ductility, the γ-TiAl intermetallics form a large negative shear plane at the processing exit, resulting in edge rupture. By comparison with the experimental results, it is found that both the surface roughness and the edge fracture size of the γ-TiAl intermetallic compound milling are smaller than the simulated values obtained from the mesoscopic hexagonal thin layer model and slightly higher than that obtained from the rectangular thin layer model The simulation value. At the same time, the surface roughness and edge fracture size increased with the increase of cutting depth, but the influence of cutting rate was smaller. Therefore, in order to get a better machined surface quality, the γ-TiAl intermetallic compound process should be used to a higher cutting rate, rather than the depth of cut.