Butt-joint brazing method for Kovar alloy and copper

Abstract

The invention provides a butt-joint brazing method for a Kovar alloy and copper. The butt-joint brazing method for the Kovar alloy and the copper comprises the following steps: after a workpiece A made of the Kovar alloy and a workpiece B made of the copper are in butt joint, placing a proper amount of brazing filler metal and brazing flux at the joint, and then placing a heating rod of high-frequency induction heating equipment around the periphery of the joint; heating the brazing filler metal and the brazing flux to a preheating temperature and keeping for a proper time; heating to a melting temperature to melt the brazing filler metal, the brazing flux and part of materials of the workpiece to form a welding seam; and naturally standing the welding seam for a proper time, heating the welding seam to a melting temperature, keeping the melting temperature for a proper time, and naturally cooling the welding seam to normal temperature. By the adoption of the technical scheme provided by the invention, the heating rod is arranged to be in the closed annular shape, the periphery of the joint of the workpieces is evenly heated, the step-by-step working procedures of preheating, heating and then strengthening are adopted in the welding process, and the brazing filler metal and the workpiece material are evenly fused so as to penetrate into the workpiece material through the capillary effect, so that the welding seam strength and the welding quality are improved.

Description

technical field [0001] The invention belongs to the technical field of brazing technology, and in particular relates to a butt brazing method of a valveable alloy and copper. Background technique [0002] In the welding process, the welding between dissimilar metal materials has always been difficult. The brazing technology relies on heating to form a liquid brazing material under the action of capillary and gravity, so that the brazing fills the gap between the joints of the workpieces. Technology, brazing technology has the advantages of short welding time, high efficiency, high precision, etc. It is especially suitable for welding and connecting workpieces with complex shapes. The existing brazing technology mainly includes high-frequency heating brazing and flame heating brazing. However, there are not many reports on the brazing technology of two dissimilar metal materials, valveable alloy and copper. In the brazing process of valveable alloy and thin-walled copper tube...

AI Technical Summary

Problems solved by technology

[0002] In the welding process, the welding between dissimilar metal materials has always been difficult. The brazing technology relies on heating to form a liquid brazing material under the action of capillary and gravity, so that the brazing fills the gap between the joints of the workpieces. Technology, brazing technology has the advantages of short welding time, high efficiency, high precision, etc. It is especially suitable for welding and connecting workpieces with complex shapes. The existing brazing technology mainly includes high-frequency heating brazing and flame heating brazing. However, there are not many reports on the brazing technology of two dissimilar metal materials, valveable alloy and copper. In the brazing process of valveable alloy and thin-walled copper tube, due to the thin wall of copper tube, The valveable alloy and the thin-walled copper pipe are connected by a thread pair, and the tooth shape of the thread pair is small. It is difficult to control the heating temperature of the solder through high-frequency induction heating equipment. If the temperature is too high, it will easily exceed the melting point of the copper pipe. If the heating temperature is too low, the melting point of the silver solder will not be reached, and it is difficult for the solder to penetrate into the thread through capillary and gravity, so secondary heating is required. In addition, capillary action during brazing heating Very weak, if there is a corner that interrupts the capillary action of the solder, the fluidity of the solder is relatively poor, and at the same time, it is easy to accumulate solder at the root of the thread, and it is difficult to control the uneven brazing gap, so the thread processing accuracy is high; the gap is too small, It is difficult to screw the thread; if the gap is too large, the amount of solder is insufficient and the penetration rate is low; when the amount of solder is insufficient, it is difficult to replenish the external solder, which affects the strength of the weld

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