Preparation method of powder metallurgy material for train brake pad

Abstract

The embodiment of the invention provides a preparation method of a powder metallurgy material for a train brake pad. The powder metallurgy material comprises the following components by weight percent: 40-50% of copper powder, 10-25% of iron powder, 8-15% of ferro-manganese ore powder, 2-7% of silica, 5-9% of molybdenum disulfide, 2-8% of aluminum oxide, 1-5% of boron nitride, 15-25% of graphite and 0.2-1% of polyacrylonitrile fiber. In the preparation method, the components are evenly mixed by a high speed stirrer and then pressed into a biscuit; and the biscuit is fixed on a support steel back, and the required powder metallurgy material is obtained by a high temperature sintering technology. The powder metallurgy material obtained by implementation of the technical scheme has the advantages of over 125 MPa of compressive strength, excellent friction stability and heat resistance, thus the compressive strength and braking performance of the brake pad can meet the braking requirements of a high-speed train with a speed of 300km / h or beyond.

Description

technical field [0001] The invention relates to the field of train brake shoes, in particular to a preparation method of powder metallurgy materials for train brake shoes. Background technique [0002] At present, the railway is an important infrastructure of the country, the main artery of the national economy and a means of mass transportation. In order to ensure the high-speed and safe operation of high-speed EMUs, a stable and good braking system must be available, and the brake pads are the key components and vulnerable parts of the high-speed train braking system. With the continuous improvement of the running speed of high-speed EMUs, the braking load of the train has also increased significantly. During braking, the brake pads convert huge kinetic energy into heat energy through friction. Therefore, the brake pad braking material should have high mechanical strength. Good heat resistance and thermal conductivity, stable friction properties, low wear and reduced wear...

AI Technical Summary

Problems solved by technology

[0003] There are two types of brake pad materials commonly used in the prior art: powder metallurgy and polymer composite materials. Among them, polymer composite materials cannot be applied to the braking of high-speed trains with a speed of more than 300 kilometers per hour due to their low strength, poor heat resistance, and severe heat decay. Requirements; and by optimizing the formula and process, powder metallurgy can achieve high strength, good thermal conductivity, stable friction performance, etc., so it is an ideal brake material for brake pads. At present, metal tin is usually added to the powder metallurgy material system to form Cu -Sn alloy to strengthen the matrix, but since tin is a low-melting metal (231.86°C), the use temperature of the powder metallurgy material made of the matrix is ​​below 500°C, and the strength and friction properties of the material will be lower after exceeding 500°C sharp recession, will not be able to brake effectively

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