共查询到4条相似文献,搜索用时 0 毫秒
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《Machining Science and Technology》2013,17(1):115-129
Three multilayer-coated carbides [two trigon-shaped inserts: Ti(C,N)/TiC/Al2O3 (T1), Ti(C,N)/ Al2O3/TiN (T2) and one 80°-rhomboid shaped insert: TiC/Al2O3/TiN (T3)] were used to machine a martensitic stainless steel at various combinations of cutting speed and feed rate without coolant to assess their wear performance. Significant nose wear and chipping/fracture of the cutting edge were the predominant failure modes affecting tool performance at higher speed conditions. Plucking of tool materials was the main rake face wear phenomenon observed on T1 grade insert with alumina as the top-layer coating when machining at the lower speed conditions. Attrition and plastic flow were the main wear mechanisms observed on the ceramic coating layers, with dissolution-diffusion being the probable wear mechanism of the tool grades where tungsten carbide substrate had direct contact with the flowing chip. The fitted statistical wear models revealed T3 grade insert with 80°-rhomboid shape as having the highest speed-feed capability, resulting in the highest material removal rate relative to T1 and T2 grade inserts with trigon shapes. 相似文献
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I. Al-Zkeri J. Rech T. Altan H. Hamdi F. Valiorgue 《Machining Science and Technology》2013,17(1):36-51
This paper investigates the effects of edge radius of a round-edge coated carbide tool on chip formation, cutting forces, and tool stresses in orthogonal cutting of an alloy steel 42CrMo4 (AISI 4142H). A comprehensive experimental study by end turning of thin-walled tubes is conducted, using advanced coated tools with well-defined cutting edge radii ranging from 5 to 68 microns. In parallel, 2-D finite element cutting simulations based on Lagrangian thermo-viscoplastic formulation are used to predict the cutting temperatures and tool-stress distributions within the tool coating and substrate. The results obtained from this study provide a fundamental understanding of the cutting mechanics for the coated carbide tool used, and can assist in the optimization of tool edge design for more complex geometries, such as chamfered edge. Specifically, the results obtained from the experiments and simulations of this study demonstrated that finite element analysis can significantly help in optimizing the design of coated cutting tools through the prediction of tool stresses and temperatures, especially within the coating layer. 相似文献
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硫酸装置某进口SO2主风机正常运行中先后两次发生叶轮叶片断裂事故,经断口SEM、金相组织、金属化学成分、叶片静频等方面的综合分析[1-3],找到了叶轮断裂失效的原因。根据该结论,提出了叶轮国产化改造方案,改半开式叶轮为闭式叶轮,保障了SO2主风机的稳定运行。 相似文献