| The quality and performance of a product have direct relation with its surface integrity. With the constant progress of science and technology, modern products not only focus on improving machining accuracy, but also pay more attention to improve the surface quality of parts, which is aimed at improving the comprehensive performance of the product. Improvement of surface integrity has become one of the developing directions of modern manufacturing technology. When structure size and material quality of parts are determined, surface integrity are the key factors influencing the fatigue property. Experience of aviation parts fracture failure has shown that the main cause of both dynamic load fatigue damage and static load delay fracture is improper processing surface condition (surface integrity). So it has significant sense for technology and economy to research surface integrity.In general, in order to obtain required surface quality, surface finishing technology is used as the finial process. Among the surface finishing technology, barreling finishing technology is one of the most widely used processes. As a new and widely applied technology, barrel finishing technology can refine the surface roughness, improve physical and mechanical properties of surface, improve surface quality of parts and operation performance. Compared with manual and other surface finishing technology, it can save a lot of labor intensity and the need to control the process of the metal parts. Moreover, it has advantages of good economic benefit, high production efficiency, good processing effect, low cost and simple operation.In view of the current special widely used superplastic materials of TC4and its bad surface problems caused by machining, barrel finishing technology is used to experiment on it, expecting to improve its surface integrity. The main research contents of the article are as follows:1)They are studied by orthogonal experiment and single factor experiment, including the improvement of TC4surface roughness, the main factors affecting surface roughness and the influence of barrel finishing parameters on surface roughness. Orthogonal experiments showed that barrel finishing parameters ordered by influence on surface roughness are the diameter of grinding block, the processing time, drum rotational speed and the type of grinding block, and good factors level collocation for this test are the drum rotating speed of250r/min, grinding block sΦ5mm in diameter, SiC grinding block, processing time of10minites. Conclusions by Single factor experiment for block type, processing time, grinding block diameter and drum rotational speed respectively are Al2O3,15min, sΦ5mm and350r/min.2)It is studied by orthogonal experiment, including the change of surface hardness and the main factors affecting it. Orthogonal experiments showed that barrel finishing parameters ordered by influence on surface hardness are drum rotational speed, the diameter of grinding block, the processing time and the type of grinding block, and good factors level collocation for this test are the drum rotating speed of350r/min, grinding block sΦ5mm in diameter, SiC+Al2O3mixed grinding block, processing time of15minites.3)Influence of drum rotational speed and the diameter of grinding block on the microstructure of surface are studied by single factor experiment. Studies have shown that with the drum rotating speed of300r/min and grinding block diameter sΦ3mm, other conditions being equal, after barrel finishing processing, grain is refined, and grain boundaries increase. At this point processing effect is better.4)Surface residual stress of TC4is studied after barrel finishing by ABAQUS/Explicit finite element software. Influence of drum rotational speed, the diameter of grinding block, the processing time and the type of grinding block on Surface residual stress distribution are mainly studied. It is found that barrel finishing technology can significantly improve the residual stress distribution on workpiece surface. |
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