High-performance magnesium alloy welding active agent

Abstract

The invention discloses a novel active agent for improving the welding performance of magnesium alloy argon tungsten-arc welding, belonging to the welding technology of active agents. The novel active agent is characterized by consisting of MnCl2 and ZnO, wherein the active agent has the weight ratio of MnCl2 to ZnO of (65%-75%); (25%-35%). A preparation method of the novel active agent comprises the following steps of: grinding MnCl2 and ZnO active agent powder, mixing in proportion, and adding acetone into a mixture, so that the active agent is pasty; evenly coating the pasty active agent on the surface of a sample by a flat hair bush, wherein the coating width is about 40mm, and the average coating quantity of the active agent is 6mg / cm<-2>; and carrying out argon tungsten-arc welding after the acetone is volatilized. Compared with the welding joint which is uncoated with the active agent, the tensile property of the welding joint obtained by the welding technology is improved by 22.8%. Compared with the welding joint which is coated with the single active agent, the tensile property of the welding joint is improved by 60.7%. The difficulties of the high possibility of the narrow melting depth in the magnesium alloy TIG (tungsten-arc welding) welding and the high possibility of the coarse crystalline grains in the A-TIG (argon tungsten-arc welding) welding can be solved.

Description

technical field [0001] A new active agent for improving the welding performance of argon tungsten arc welding of magnesium alloys. Including the following process, it is characterized in that: before welding, the MnCl 2 and ZnO active agent powder are milled and mixed in proportion, and then acetone is added to the mixture to make it into a paste. Then use a flat brush to evenly coat the pasty active agent on the upper surface of the sample, the coating width is about 40 mm, and the average coating amount of the active agent is 6 mg cm -2 . Argon tungsten arc welding is performed after the acetone evaporates. Background technique [0002] Magnesium alloys have attracted increasing attention due to their low specific gravity, good processing performance, and abundant natural reserves. Compared with other metal materials and engineering plastics, magnesium alloy has high specific strength and specific stiffness, excellent damping and shock absorption, electromagnetic shiel...

AI Technical Summary

Problems solved by technology

[0003] The above research mainly solves the problems of shallow penetration and low welding efficiency of TIG welding, but the coverage of active agent in the process of magnesium alloy active welding often has adverse effects on the structure and performance of welded joints.

For example: due to the poor thermal conductivity of the active agent, it covers the surface of the molten pool, which reduces the temperature gradient of the molten pool and reduces the cooling rate of the molten pool, resulting in severe coarsening of the grains in the fusion zone of the magnesium alloy.

This phenomenon greatly reduces the mechanical properties of welded joints.

Images