銅−タングステン焼結合金と無酸素銅との摩擦圧接におけるタングステン含有量の影響 第１報 銅−タングステン焼結合金と無酸素銅との摩擦圧接部の高温変形

Abstract

The deformation behavior of the weld during the friction welding of copper-tungsten sintered alloy (Cu-W) to oxygen free copper (OFC) has been investigated for W contents from 70 mass% to 100 mass% (pure tungsten). At the friction pressure of 50MPa, the degree of the deformation of the Cu-W was negligibly small compared with that of the OFC. As the W content was increased, the friction time at which the OFC started deforming was increased, and the deformation rate of the OFC was decreased. The friction torque and the temperature at friction interface were decreased with the increase in the W content. In order to interpret these results, the temperature at friction interface is calculated, assuming that the friction interface is a plane heat source generating the heat proportional to the friction torque and that deformation of the OFC and Cu-W is negligible. The calculated temperature is in good agreement with the experimental in the early stage of the friction process. From this calculation, the temperature at which the OFC starts deforming is estimated to be 810-830 K irrespective of the W content from 80 to 100 mass%. Therefore, it can be accounted for by the decrease in the heating rate of the friction interface that the friction time at which the OFC started deforming was increased with the W content. The decrease in the deformation rate of the OFC can also be accounted for by the decrease in the friction torque and resulting decrease in the heating rate.