A Friction Stir Welding Process Method for Mobile Heating of the Back of Copper and Aluminum Dissimilar Metals of Thick Plates

Abstract

A friction stir welding process method for mobile heating of the back of thick copper-aluminum dissimilar metals, the steps are: horizontally fix the workpiece to be welded on the ceramic panel, and keep the centerline of the area to be heated on the copper plate coincident with the centerline of the steel backing plate ; Start the induction cooker, heat the steel backing plate through the alternating magnetic field of the induction cooker, and the steel backing plate will transfer the heat to the back of the weldment; start the friction stir welding equipment to ensure that the rotation speed of the stirring head and the speed of entering the workpiece meet the predetermined process requirements; The set welding speed moves the stirring head, and at the same time moves the induction cooker synchronously along the track until all the welding work is completed. The invention reduces the temperature gradient difference of the base metal in the thickness direction, improves the inhomogeneity of the weld seam structure, reduces the welding stress, and improves the friction stir welding quality of thick plate workpieces.

Description

technical field [0001] The invention relates to a friction-stir welding technology, in particular to a friction-stir welding process for carrying out movable heating on the back side of thick copper-aluminum dissimilar metals. Background technique [0002] Friction stir welding technology has been quite maturely applied to the welding of low-melting point metal materials, but for the welding of thick copper-aluminum dissimilar metal materials, due to its large heat absorption cross-section and long vertical heat transfer path, it often results in parentheses in the weld area. Insufficient material temperature rise and poor temperature gradient lead to poor weld fusion defects. All these factors severely limit the application range of friction stir welding technology for thick copper-aluminum dissimilar metal materials. Similar literature retrieved so far is "A Friction Stir Welding Process Combining Backside Heating and Frontal Quenching" and "A Method for Improving the Temp...

AI Technical Summary

Problems solved by technology

[0002] Friction stir welding technology has been quite maturely applied to the welding of low-melting point metal materials, but for the welding of thick copper-aluminum dissimilar metal materials, due to its large heat absorption cross-section and long vertical heat transfer path, it often results in parentheses in the weld area. Insufficient material temperature rise and poor temperature gradient lead to poor fusion defects of the weld seam. All these factors seriously limit the application range of friction stir welding technology for thick copper-aluminum dissimilar metal materials.

Similar literature retrieved so far is "A Friction Stir Welding Process Combining Backside Heating and Frontal Quenching" and "A Method for Improving the Temperature Gradient in the Thickness Direction of Friction Stir Welding of Large-Thickness Aluminum Alloys". The heating device is a long block heating plate structure, the heating area is integrated, and the heating temperature is not easy to adjust, so that the heating device is not targeted and the thermal efficiency is not high; The direct heating method on the back of the plate cannot solve the problem of process support on the back of the weld, so there is an urgent need for a new back heating assisted friction stir welding process with precise heating characteristics

Images