A method of ultrasonic welding nickel-titanium shape memory alloy thin plate

Abstract

A method for ultrasonically welding nickel-titanium shape memory alloy thin plates, coating nano-titanium hydride and nickel formate-coated nano-nickel mixed particles between the nickel-titanium shape memory alloy thin plates to be welded to form an intermediate layer, the mixed particles are made of nanometer Titanium hydride and nickel formate coated nano-nickel particles are mechanically mixed at a molar ratio of 1:1, and the thickness of the middle layer is 20-40 μm; the nickel-titanium shape memory alloy sheet coated with the middle layer of mixed particles is ultrasonically welded, and the welding time is 0.55-0.9s, the welding pressure is 45-70psi, and the welding amplitude is 40-65μm; the invention can improve the welding rate of the ultrasonically welded nickel-titanium shape memory alloy sheet interface, thereby improving the mechanical properties of the ultrasonically welded nickel-titanium shape memory alloy joint , using nano-titanium hydride and nickel formate coated nano-nickel mixed particles as the intermediate layer to assist ultrasonic welding of nickel-titanium shape memory alloy joints, the maximum shear strength can reach 2890N.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a method for ultrasonically welding nickel-titanium shape memory alloy thin plates. Background technique [0002] Nickel-titanium shape memory alloy has the advantages of superelasticity and shape memory effect, and is widely used in medical equipment, aerospace, machinery, instrumentation and other fields; at present, the connection methods of nickel-titanium shape memory alloy are mainly laser welding, electron beam welding And TIG welding, etc., when the above method is used for welding, the nickel-titanium shape memory alloy will be melted, the grains in the subsequent weld will be coarsened, and the texture will change greatly. The high-temperature heat source will cause the evaporation of nickel, and the weld will There is obvious thermal influence, resulting in uneven stress distribution near the weld, thus affecting the function of nickel-titanium shape memory alloy. ...

AI Technical Summary

Problems solved by technology

[0002] Nickel-titanium shape memory alloy has the advantages of superelasticity and shape memory effect, and is widely used in medical equipment, aerospace, machinery, instrumentation and other fields; at present, the connection methods of nickel-titanium shape memory alloy are mainly laser welding, electron beam welding And TIG welding, etc., when the above method is used for welding, the nickel-titanium shape memory alloy will be melted, the grains in the subsequent weld will be coarsened, and the texture will change greatly. The high-temperature heat source will cause the evaporation of nickel, and the weld will There is obvious thermal influence, resulting in uneven stress distribution near the weld, thus affecting the function of nickel-titanium shape memory alloy

[0003] As a solid-state welding technology, ultrasonic welding technology has the advantages of short welding time, low energy consumption, environmental protection, and no welding porosity compared with laser welding, electron beam welding and TIG welding, and has small heat input and no heat-affected zone. It can be used for Welding nickel-titanium shape memory alloys; however, due to the high hardness of nickel-titanium shape memory alloys, there are certain difficulties in ultrasonic welding of nickel-titanium shape memory alloys, resulting in low welding rate of ultrasonic welded nickel-titanium shape memory alloy joints, thus Affects the performance of joints; therefore, it is urgent to adopt a method that can improve the interface welding rate of ultrasonic welding nickel-titanium shape memory alloy sheets and the mechanical properties of joints