Welding forming method of thin invar alloy

Abstract

The invention discloses a welding forming method of a thin invar alloy. The welding is carried out by adopting an Nd: YAG laser device. The welding forming method comprises the steps of: fixing the invar alloy in a fixture and then installing the invar alloy on a workbench; adjusting the pulse width and the pulse frequency of the Nd: YAG laser device, relative position of the laser and the thin invar alloy and the pressure of a side-blown protective gas; determining proper laser average line energy density; and carrying out forming welding on the thin invar alloy. The welding of the invar alloy is realized directly by using the laser, so that extra welding wires are not needed while welding. The pulse width, the pulse frequency and the defocusing amount of the laser device are continuously adjustable, so that the invar alloy of 0.5-2 mm in thickness can be formed by autogenous welding. And the pulse laser line energy density of the Nd: YAG laser device in the invention is between 100-900 J / mm, therefore, the welding line without obvious positive and negative weld reinforcements and pores and cracks can be realized, and follow-up processes to the welding line are not needed.

Description

technical field [0001] The invention relates to a welding technology, in particular to a welding forming method of a thin Invar alloy. Background technique [0002] With the continuous development of science and technology, Invar alloy (Invar36) has been widely used in aerospace, petrochemical transportation, and IC equipment manufacturing industries due to its low thermal expansion coefficient, such as for satellite positioning equipment bases, liquefaction Natural gas constant temperature transport tanks, composite molds for aircraft, microwave resonators in the electronics field and specific functional parts for lithography machines, etc. The above application fields without exception involve the welding process of Invar alloy, so the welding technology of Invar alloy directly affects the manufacturing accuracy and use effect of parts in the above application fields. At present, the methods for welding Invar alloy materials with a thickness of more than 2mm include: arc ...

AI Technical Summary

Problems solved by technology

The above application fields without exception involve the welding process of Invar alloy, so the welding technology of Invar alloy directly affects the manufacturing accuracy and use effect of parts in the above application fields

At present, the methods that can realize the welding of Invar alloy materials with a thickness of more than 2mm include: arc welding and submerged arc welding, but welding of Invar alloy materials with a thickness of 0.5-2mm has not been reported yet.

Moreover, hot cracks are likely to occur when welding with the above method, and the requirements for the composition of the additional welding wire are very harsh. The thin plate welding process has strict requirements for arc control, and the phenomenon of weld reinforcement is obvious, which increases the difficulty of control of the welding process and the follow-up treatment process. Application of Invar Welding Technology

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