Method for preparing gray iron-base composite material for in situ production of tungsten carbide

Abstract

The invention discloses a method for preparing a gray iron based composite material for generating tungsten carbide in situ. The method comprises the following steps: weaving tungsten wires into a tungsten wire net with certain specification, and cutting, coiling or overlapping the tungsten wire net to form a fixed structure which is preset in a die cavity of a casting mould; and smelting the gray iron to obtain molten gray iron to be poured into a casting mould, and cooling and cleaning the casting mould to obtain the gray iron based composite material for generating the tungsten carbide in situ. The gray iron based composite material for generating the tungsten carbide in situ prepared by the method can obtain evenly-distributed tungsten carbide hard phases at the position of the tungsten wire net through the reaction in situ of the tungsten in the tungsten wire net and the carbon in the gray iron. The gray iron based composite material fully plays the high wear resistance of the tungsten carbide hard phases and the good toughness of the gray iron, the hard phases are arranged orderly and are distributed evenly, the regulation and the control are convenient, and the process is reliable, thus the gray iron based composite material can be widely used in the wear resisting fields such as mine, electric power, metallurgy, coal, building materials and the like for producing wear resistant parts with various shapes and any size specification.

Description

technical field [0001] The invention belongs to the technical field of metal-based composite materials, and in particular relates to a method for preparing a gray iron-based composite material in which tungsten carbide is generated in situ. Background technique [0002] Gray iron is cheap and is the most widely used cast iron. It is generally used to manufacture brackets, gearboxes, valve bodies, bearing seats and other parts. However, due to the lack of hard phases such as carbides in gray iron, its macroscopic hardness is very low, so gray iron cannot resist the cutting and wear effect of abrasives on the surface of parts under wear conditions, which makes it difficult for gray iron to be applied to abrasive wear On the equipment parts, it greatly limits its scope of use. [0003] In recent years, a composite preparation process reinforced by ceramic particles has appeared to improve the wear resistance of gray iron, such as placing tungsten carbide or titanium nitride pa...

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Problems solved by technology

However, due to the lack of hard phases such as carbides in gray iron, its macroscopic hardness is very low, so gray iron cannot resist the cutting and wear effect of abrasives on the surface of parts under wear conditions, which makes it difficult for gray iron to be applied to abrasive wear equipment parts, greatly limiting its scope of use

[0003] In recent years, a composite preparation process reinforced by ceramic particles has appeared to improve the wear resistance of gray iron, such as placing tungsten carbide or titanium nitride particles on the bottom of the mold, and then pouring gray iron, but the preparation process is difficult to control stably. Particle distribution is not uniform, and it is still difficult to obtain an overall wear-resistant gray iron with uniform reinforcement distribution

There are also hard particles such as tungsten carbide solidified with a binder, put them into the mold, and then pour the molten metal to make the hard particles and the molten metal penetrate and fuse with each other. However, due to the decomposition of the binder at high temperature, a large amount of gas is generated. Lead to the formation of many pores inside the composite layer, the effect is not ideal

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