Carbide blade laser brazing method

Abstract

A carbide blade laser brazing method comprises the following steps of (1) material selecting; (2) tight ejecting and stable pressing; (3) brazing. According to the carbide blade laser brazing method, by means of laser brazing, focusing light spots are small, high-precision flexible positioning can be achieved, and performance is stable; centralized flexible control can be achieved through a robot, the adaptability to workpieces is high, the brazing time can be effectively saved in mass production, and the production cost can be reduced; the effective connection between dissimilar materials is achieved, the brazing quality is high, brazing seams are smooth and attractive, the thermal influence area is small, and the probability of cracking of cemented carbide can be effectively lowered. Copper brazing wires are fully melted, the brazing seams are soaked and are smooth and flat, and the macro defects such as obvious pores and cracks are avoided.

Description

technical field [0001] The invention relates to a laser brazing method of a cemented carbide blade, in particular to a laser brazing method based on an optical fiber coupled output solid-state laser in the manufacture of a cemented carbide blade. Background technique [0002] Cemented carbide is an alloy made by powder metallurgy with high hardness and high melting point metal carbides (WC, TiC, etc.) as the matrix and metal Co as the binder. Due to its high hardness (69-81HRC), good thermohardness (up to 900-1000°C, maintaining 60HRC) and good wear resistance, cemented carbide is widely used in cutting tools. material, and the cutting speed is 4-7 times higher than that of high-speed steel, and the tool life is 5-80 times higher. Cemented carbide cutting tools account for 80% of the total sales of various cutting tools, and are most widely used in high-speed cutting tools. At present, cemented carbide cutting tools in developed countries account for as much as 70% of the ...

AI Technical Summary

Problems solved by technology

At present, cemented carbide cutting tools in developed countries account for as much as 70% of the cutting tool industry, occupying a dominant position, but the proportion of cemented carbide cutting tools in my country is less than 25%, which is not only far from the product structure of cutting tools in the international market, but also cannot satisfy domestic manufacturing. Industry's growing demand for carbide cutting tools

Cemented carbide contains a relatively high content of carbides and alloying elements. When the fusion welding method is used to directly weld the cemented carbide and the blade substrate, it is easy to appear: (1) Welding cracks

The thermal expansion coefficient of cemented carbide is small, generally 1 / 2 to 1 / 3 of steel. Since cemented carbide and steel cannot shrink synchronously after welding, high residual stress will be formed in the weld zone, and in cemented carbide Most of the upper part is tensile stress, which leads to cracking of cemented carbide

(2) Weld embrittlement

[0004] Therefore, the brazing method is generally used to connect the cemented carbide and the blade substrate. The commonly used brazing methods include oxyacetylene flame brazing, high-frequency induction brazing, contact brazing and copper-immersion brazing, etc., but these brazing methods When using oxyacetylene flame brazing method, some problems are prone to occur. For example, when oxyacetylene flame brazing is used, it is difficult to control the flame temperature. When brazing, the steel and hard alloy are heated as a whole, and cracks are likely to occur in the hard alloy, and the brazing material is easily oxidized, and impurities are mixed into the weld, which reduces the tensile strength of the weld.

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