The objective of the this study is to investigate the effects of cutting parameters on thermal characteristics, including practical cutting regions, the formation of the kerfwidth and the heat transfer phenomenon, in ...The objective of the this study is to investigate the effects of cutting parameters on thermal characteristics, including practical cutting regions, the formation of the kerfwidth and the heat transfer phenomenon, in the cutting of Inconel 718 super-alloy sheets using a CW Nd：YAG laser. From the results of the experiments, the influence of process parameters on both the practical cutting region and the kerfwidth has been examined. In addition, it has been shown that the kerfwidth of the specimen lies in the range of 0.53-0.61 mm. In order to examine characteristics of the heat transfer during the laser cutting process, a three-dimensional quasi-steady heat transfer analysis has been performed using the commercial code SYSWELD V9.0. From the results of the analysis, the influence of cutting parameters on the temperature distribution in the vicinity of the cut section has been quantitatively evaluated. Based on these results, optimal cutting conditions have been estimated.展开更多
In this paper, the p-torsion in homotopy groups π_nX of a CW complex X is studied, Z_phomology groups H_π(X; Z_p) and fundamental group π_1X are used to obtain sufficient conditions for infinitely many n such that ...In this paper, the p-torsion in homotopy groups π_nX of a CW complex X is studied, Z_phomology groups H_π(X; Z_p) and fundamental group π_1X are used to obtain sufficient conditions for infinitely many n such that Tor (π_nX, Z_p)≠0.展开更多
基金supported by a grant-in-aid for Regional Innovation Center (RIC), New Technology Development and Research Center of Laser Application in Chosun University, from ITEP and MOICEpartly supported by the National Core Research Center Program from MOST and KOSEF (No.R15-2006-022-01001-0)
文摘The objective of the this study is to investigate the effects of cutting parameters on thermal characteristics, including practical cutting regions, the formation of the kerfwidth and the heat transfer phenomenon, in the cutting of Inconel 718 super-alloy sheets using a CW Nd：YAG laser. From the results of the experiments, the influence of process parameters on both the practical cutting region and the kerfwidth has been examined. In addition, it has been shown that the kerfwidth of the specimen lies in the range of 0.53-0.61 mm. In order to examine characteristics of the heat transfer during the laser cutting process, a three-dimensional quasi-steady heat transfer analysis has been performed using the commercial code SYSWELD V9.0. From the results of the analysis, the influence of cutting parameters on the temperature distribution in the vicinity of the cut section has been quantitatively evaluated. Based on these results, optimal cutting conditions have been estimated.
基金Project supported by the National Natural Science Foundation of China
文摘In this paper, the p-torsion in homotopy groups π_nX of a CW complex X is studied, Z_phomology groups H_π(X; Z_p) and fundamental group π_1X are used to obtain sufficient conditions for infinitely many n such that Tor (π_nX, Z_p)≠0.
