Hard alloy taking Ni-Al intermetallic compound as binding phase and preparation method thereof

Abstract

The invention discloses a hard alloy taking a Ni-Al intermetallic compound as a binding phase and a preparation method thereof. WC-Al4W pre-alloy powder is taken as a precursor, tungsten carbide powder, nickel powder, the WC-Al4W pre-alloy powder and carbon black are sintered to form the hard alloy taking the Ni-Al intermetallic compound as the binding phase, and the binding phase is the single NiAl binding phase or the single Ni3Al binding phase or the NiAl-Ni3Al joint binding phase or the Ni3Al-Ni joint binding phase. The hard alloy taking the Ni-Al intermetallic compound as the binding phase, disclosed by the invention, has the advantages of uniform distribution of the binding phase, high density, high alloy strength and no residues of aluminum oxide in the binding phase, and can avoid brittle fracture initiation produced by the existence of the aluminum oxide and improve the using performances of the alloy. The preparation method disclosed by the invention has the advantages of simple preparation process, easiness in quality control and low production cost, and is conductive to large-scale production.

Description

technical field [0001] The invention belongs to the technical field of tungsten carbide-based cemented carbide, and in particular relates to a cemented carbide with Ni-Al intermetallic compound as a binding phase and a preparation method thereof. Background technique [0002] At present, the use of intermetallic compounds as the bonding phase of cemented carbide is a very effective method to improve the oxidation resistance and high temperature strength of traditional cemented carbide, especially the use of Ni-Al intermetallic compounds as the bonding phase of cemented carbide. With obvious advantages, Ni-Al intermetallic compounds are superior in oxidation resistance, carburization prevention and wear resistance. What is particularly prominent is that below 800 °C, the strength of Ni-Al intermetallic compounds does not decrease continuously with the increase of temperature, but first increases with the increase of temperature, and then decreases after reaching a certain hig...

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Problems solved by technology

But there are still some deficiencies, because the temperature for preparing intermetallic compound pre-alloy powder is low, so a small amount of alumina in the raw material of aluminum powder and a small amount of alumina formed in the process of preparing pre-alloy powder cannot be reduced, and this part of alumina will also be reduced. Residues in the cemented carbide form the fracture source of the cemented carbide, and at the same time form aggregates in the process of preparing intermetallic compound pre-alloyed powder, resulting in poor distribution uniformity of the binder phase in the cemented carbide

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