Composite welding method and device for silicon carbide reinforced aluminum matrix composite

Abstract

The invention discloses a hybrid welding method and device for silicon carbide reinforced aluminum matrix composites.The hybrid welding method comprises the following steps that S1, a laser welding head emits a laser beam to conduct laser welding on a workpiece to be welded in the welding direction, and a friction stir welding machining head is arranged behind the laser welding head; carrying out friction stir welding on the laser-welded weld joint along the welding direction by utilizing waste heat after solidification of a laser welding pool, and enabling the width of a stirring pool formed by the friction stir welding to be greater than that of the laser welding pool; and S2, after the laser welding head reaches the welding end point, laser beam emission is stopped, the laser welding head is moved out of the to-be-welded workpiece, then after the friction stir welding machining head reaches the welding end point, the friction stir welding machining head is moved out of the to-be-welded workpiece, and welding is completed. The silicon carbide reinforced aluminum matrix composite can be efficiently welded, the welding quality is high, and the welding cost can be reduced.

Description

technical field [0001] The invention relates to the technical field of special material welding, in particular to a composite welding method and device for silicon carbide reinforced aluminum-based composite materials. Background technique [0002] Aluminum alloy has the advantages of high specific strength, good corrosion resistance and good electrical and thermal conductivity. It is one of the most widely used metal materials in aerospace and other fields. research hotspot. Compared with other particles, silicon carbide particles have the characteristics of high strength, high hardness, high laser absorption rate, and good bonding with aluminum alloys, and have been practically used in aerospace and other fields. [0003] Laser welding is one of the important aspects of the application of laser material processing technology. It is an efficient and precise welding method by using a high-energy-density laser beam as a heat source. The welding process is of the heat conduc...

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Problems solved by technology

[0005]However, there are still various problems in welding silicon carbide reinforced aluminum matrix composites only by laser welding or friction stir welding, mainly reflected in the laser welding of silicon carbide reinforced aluminum matrix composites. After the aluminum matrix composite material is melted, the area of ​​the weld seam will form unevenly distributed sheet-like and layered Al4C3 crystal structures, which have poor plasticity, high brittleness, and extremely large Affects the mechanical properties of the weld zone

In the heat-affected zone, there will also be uneven distribution and burning of the silicon carbide reinforcement phase, resulting in jittering of the mechanical properties of the material, which will affect the welding quality

However, due to the high hardness and high strength of silicon carbide reinforced aluminum matrix composites, friction stir welding has a large frictional resistance, which greatly accelerates the wear of the stirring needle, and its processing efficiency is low and the cost is high.

None of the existing friction stir-laser welding patents considers the problem of the wide difference in weld width between laser welding and friction stir welding. Taking the 1mm thick Zn-Cu-Ti alloy plate material as an example, the average width of the weld seam of the friction stir welding head is 4.5mm, the average width of the weld seam of the laser welding head is 1.0mm, the huge difference in the weld seam leads to the waste heat of the material after laser welding can not effectively reduce the resistance in the friction stir welding, and the composite welding combination effect is poor, so we provide a silicon carbide The composite welding method of reinforced aluminum matrix composites has become an urgent technical problem to be solved

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