Diffusion welding device and method based on independent control of local weldment environment temperature

Abstract

The invention discloses a diffusion welding device based on the independent control of a local weldment environment temperature. The device is sequentially provided with a pressure control device, a pressure head, an upper insulated cushion block, an upper electrode pressure lever, a lower electrode pressure lever, a lower insulated cushion block and a support table from top to bottom, wherein weldments are arranged between the upper electrode pressure lever and the lower electrode pressure lever, and the weldments are sequentially a metal workpiece, an interlayer and a non-metal workpiece or a non-metal workpiece, an interlayer and a metal workpiece from top to bottom and also comprise a first graphite heater, a metal environment temperature measuring and controlling device, a first graphite heater power source, a second graphite heater, a second graphite heater power source and a non-metal environment temperature measuring and controlling device. The invention also discloses a diffusion welding method based on the independent control of the local weldment environment temperature. According to the device and the method disclosed by the invention, the diffusion welding temperature can be effectively reduced, and the synchronous telescoping of the non-metal workpiece and the metal workpiece in a diffusion welding process is realized.

Description

technical field [0001] The invention relates to a welding device and method, in particular to a diffusion welding device and method based on independent control of local weldment ambient temperature. Background technique [0002] Diffusion welding joints have excellent high-temperature performance and are suitable for the connection of dissimilar materials with large differences in chemical properties, such as the connection of ceramics and metals. Although it takes a long time to weld and has high requirements for surface preparation and assembly of weldments, it has broad application prospects in aerospace, nuclear engineering and other fields. [0003] The key to non-metal and metal diffusion welding is how to control welding residual stress. In recent years, scholars at home and abroad have conducted extensive research on this. In order to control the welding residual stress, an intermediate layer is often inserted in the solid phase diffusion welding joint (Ji Xiaoqia...

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Problems solved by technology

The patent (application number: 201010233919.7) proposes a SPS connection method between stainless steel and zirconia ceramics. The ambient temperature of the entire weldment is provided by a single graphite heating body, and the welding parameters are selected relatively large. The heating rate is 60~200℃ / min , The connection temperature is 1000~1100 ℃, it is easy to cause a large residual stress inside the workpiece and reduce the mechanical properties of the joint

[0004] Although the above studies have played a positive role in reducing the residual stress of the joint by non-metal and metal diffusion welding, there are still the following shortcomings: for conventional diffusion welding to insert an intermediate layer between non-metal and metal, it is often necessary to increase the connection temperature and pressure, At the same time, non-metal, intermediate layer, and metal must all go through the same welding high-temperature thermal cycle; for simply applying the resistance heat generated by pulsed large current to the whole process of non-metallic / intermediate layer / metal diffusion welding, it will inevitably cause welding heating and The cooling rate is difficult to control. Due to the large difference in thermophysical performance parameters such as thermal expansion coefficient and elastic modulus between non-metal and metal, high residual stress will also be caused during welding cooling.

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