The Ar-N2 gas tungsten arc(GTA) welding of 10 mm copper thick plates without preheating was investigated.The microstructure of weld metal and joints was observed and mechanical performance of weld metal was tested by ...The Ar-N2 gas tungsten arc(GTA) welding of 10 mm copper thick plates without preheating was investigated.The microstructure of weld metal and joints was observed and mechanical performance of weld metal was tested by using Cu-Ti welding metal with different Ti content.The Ar-N2 GTA weld of copper thick plates can eliminate the nitrogen porosities in the weld metal by adding element Ti in filler metal,which is caused by N2 gas in shield gas.The elimination degree of nitrogen porosities,the distribution of CuTiN intermetallic compound(IMC) and the mechanical performance of joints are associated with the change of the Ti content in the welding materials.And when Ti content is about 5%,nitrogen porosities is eliminated completely and the CuTiN IMC distribute dispersedly,the tensile strength and impact ductility of the joint achieve the best result,which almost reaches the lever of the base metal.展开更多
In this paper we first describe the recently developed theory of close-coupling wave packet(CCWP)method.then calculate the transition prodabilities for the Ar-N2 system in detail.The total angular momentum J=4 is chos...In this paper we first describe the recently developed theory of close-coupling wave packet(CCWP)method.then calculate the transition prodabilities for the Ar-N2 system in detail.The total angular momentum J=4 is chosen,and the nine coupled channels transition probabilities are calculated.Comparision with the results from close-coupling (CC) method shows that the CCWP method is not only more accurate but also faster in computation.展开更多
基金Funded by Program of Excellent Team in Harbin Institute of Technology
文摘The Ar-N2 gas tungsten arc(GTA) welding of 10 mm copper thick plates without preheating was investigated.The microstructure of weld metal and joints was observed and mechanical performance of weld metal was tested by using Cu-Ti welding metal with different Ti content.The Ar-N2 GTA weld of copper thick plates can eliminate the nitrogen porosities in the weld metal by adding element Ti in filler metal,which is caused by N2 gas in shield gas.The elimination degree of nitrogen porosities,the distribution of CuTiN intermetallic compound(IMC) and the mechanical performance of joints are associated with the change of the Ti content in the welding materials.And when Ti content is about 5%,nitrogen porosities is eliminated completely and the CuTiN IMC distribute dispersedly,the tensile strength and impact ductility of the joint achieve the best result,which almost reaches the lever of the base metal.
文摘In this paper we first describe the recently developed theory of close-coupling wave packet(CCWP)method.then calculate the transition prodabilities for the Ar-N2 system in detail.The total angular momentum J=4 is chosen,and the nine coupled channels transition probabilities are calculated.Comparision with the results from close-coupling (CC) method shows that the CCWP method is not only more accurate but also faster in computation.
