Alloy material with thermal expansion coefficient in gradient change and preparation method thereof

Abstract

The invention relates to an alloy material with a thermal expansion coefficient in a gradient change and a preparation method of the alloy material. The alloy material comprises a substrate material component and a thermal expansion coefficient adjusting phase component, wherein the substrate material component is one or a mixture of several elements of Cu, Ni, Cr, Mn, Co and Fe in an optional ratio; the thermal expansion coefficient adjusting phase component is one or a mixture of several fibers of W, Mo, Al2O3, SiC and Si in an optional ratio; a gradient transition alloy is at least divided into two sections; and the distribution of the components of a thermal expansion coefficient adjusting phase in each section of the alloy changes in a gradient way. The method disclosed by the invention is suitable for preparing gradient transition alloy bars and pipes, the thermal expansion coefficient of the prepared alloy material changes in the gradient way, and the alloy material is well matched with welded ceramics and metals. The gradient transition alloy has important significance to release residual stresses generated in a ceramic and metal connecting process.

Description

technical field [0001] The invention relates to an alloy material with a gradient change in thermal expansion coefficient and a preparation method thereof. Background technique [0002] Most ceramic materials have high vacuum air tightness, high thermal conductivity, high wear resistance, low vapor pressure, and good thermal and chemical stability. Therefore, ceramic materials are widely used in vacuum electronics, aviation, aerospace and other fields. However, ceramic materials also have disadvantages such as poor plasticity and poor cold workability, and are generally not used alone, but are often combined with metal materials and used in the form of connectors. [0003] In the process of sealing ceramics and metals, one of the key technologies to be solved is the relief of sealing stress. Due to the large difference in physical and chemical properties between ceramics and metal materials, especially the large difference in thermal expansion coefficient, it will directly...

AI Technical Summary

Problems solved by technology

Due to the large difference in the physical and chemical properties of ceramics and metal materials, especially the large difference in thermal expansion coefficient, it will directly lead to a large connection stress between the two, and even cause the connection to fail.

A transition layer with a coefficient of thermal expansion between the ceramic to be welded and the metal is the most direct and effective method to relieve the sealing stress, but when the thermal expansion coefficient of the ceramic to be welded is very different from that of the metal, a single or double transition layer is insufficient Relying on its own plastic deformation to eliminate the destructive effect of sealing stress on the performance of sealing parts

In addition, using too much transition layer itself will cause performance loss to the entire connection

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