Powder particles for preparing cemented carbide and method for preparing cemented carbide

Abstract

The invention discloses a preparation method of a titanium carbonitride based hard alloy capable of enhancing and toughening, powder particles used for implementing the preparation method and a preparation method of the powder particles. The preparation method disclosed by the invention comprises the following steps: 1) preparing mixed powder composed of the powder particles and iron group metal, wherein each powder particle is composed of a titanium carbonitride particle core and a cladding layer located on the surface of the titanium carbonitride particle core; each cladding layer comprises a molybdenum-chromium eutectic carbide solid solution, the weight of the powder particles accounts for 20% to 55% of the total weight of the mixed powder and the balance is the iron group metal; 2) preparing the mixed powder into a pressing blank through pressure molding; and 3) sintering the pressing blank in a vacuum or protective atmosphere and cooling to obtain the hard alloy.

Description

technical field [0001] The invention mainly relates to cemented carbide and its preparation method, in particular to titanium carbonitride-based cemented carbide and its preparation method. Background technique [0002] At present, the cutting processing based on cemented carbide accounts for more than 80% of the entire manufacturing process, and is the most important processing technology in modern manufacturing. However, cemented carbide consumes a large amount of scarce strategic resources such as tungsten and cobalt. Therefore, it is imminent to look for alternative resources of tungsten and cobalt and to develop cutting tool materials without (less) tungsten and cobalt. Titanium carbonitride-based cemented carbide is a kind of titanium carbonitride or the mixed powder of titanium carbide and titanium nitride as the main raw material of the hard phase, and Co, Ni, Mo, Fe and other metals as the bonding phase raw materials, and Usually also added with WC, TaC, NbC, Mo ...

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Problems solved by technology

The traditional addition method has the following disadvantages: 1) The transition metal carbide powder is mixed with the titanium carbonitride powder simply by mechanical mixing, although a solid solution or a transition layer compound can be formed on the hard phase titanium carbonitride during sintering The annular shell is formed, but the annular shell is usually not complete, so that a part of the titanium carbonitride in the hard phase is in direct contact with the metal of the bonding phase, causing problems such as decarburization of the hard phase, and the fracture of the cemented carbide Toughness and flexural strength decrease; 2) Due to the poor mutual compatibility of various transition group metal carbides, even if a variety of transition group metal carbides are added at the initial stage of the reaction, the various transition group metal carbides in the annular shell formed by sintering Metal carbides are not effectively dissolved in one body, so that the combination of titanium carbonitride and the binder phase cannot be effectively combined, so that the comprehensive improvement effect is not obvious. Therefore, a single transition group metal carbide is usually used to treat carbonitride. Titanium-based cemented carbide for improvement

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