Multi-phase dual-scale structure aluminum-tin-based composite bearing strip and its preparation method

Abstract

The invention provides a multi-phase dual-scale structure Al-Sn-based alloy powder / pure aluminum / steel back composite bearing pad strip, which comprises an upper multi-phase dual-scale structure Al-Sn-based alloy layer, a middle transition pure A three-layer structure consisting of an Al layer and a lower carbon steel back layer; the Al-Sn-based alloy layer is prepared by mechanical alloying and has a multi-phase dual-scale structure Al-Sn-Si-Mg-Cu mixed The powder is composed of: nanocrystalline Al-Sn-Si alloy powder + micron coarse-grained Al-Sn alloy powder + nanocrystalline Cu, Mg, Si and other trace components. The present invention also provides a preparation method of a multi-phase double-scale aluminum-tin-based alloy powder / pure aluminum / steel back composite bearing strip. Preparation of scale alloy powder, surface treatment of steel back, primary rolling compound, annealing, secondary rolling and sintering and other processes. It solves the problems arising in the industrial application process of Al-Sn-based bearing alloy prepared by mechanical alloying in the bearing bush strip, and realizes industrial production.

Description

technical field [0001] The invention belongs to the technical field of powder metallurgy manufacturing, and relates to a processing technology for synthesizing lead-free bearing bush alloy by mechanical alloying method and replacing copper-lead bearing bush strip with high-strength aluminum-tin base, in particular to a multi-phase double-scale structure aluminum-tin-base mixed Powder / pure aluminum / steel back composite bearing pad strip and its preparation method. Background technique [0002] With the development of automobiles in the direction of high performance, the engine is also developing in the direction of high speed, high power, low energy consumption, light weight and high pressure enhancement, and the bearing pad materials of automobiles are also facing high-performance development. At the same time, people's awareness of environmental protection and their own health requirements are increasing day by day. For the toxic lead element, the deleading of bearing produ...

AI Technical Summary

Problems solved by technology

However, there are two main problems in the Al-Sn alloy obtained by casting: (1) the strength of the alloy (HV30~50) is low, and it is difficult to meet the current demand for high strength of the bearing bush; (2) it is easy to serious problems such as gravity segregation

However, for Al-Sn bearings, cast aluminum-tin-based alloys are mainly used to compound steel backs, which is mainly due to the poor sintering performance between powder and powder, powder and steel backs due to the easy oxidation of aluminum, poor bonding strength, and There are three technical deficiencies in the industrial application process of the Al-Sn-based bearing alloy prepared by mechanical alloying: (1) the nanocrystalline powder has high hardness and poor fluidity, and is difficult to be rolled and compounded with the steel back; 2) Since the Al powder particles are easy to oxidize, it is difficult to use the hot rolling method, and at the same time, it is difficult to obtain a high bonding strength with the steel back in cold rolling; (3) The surface of the Al powder particles is easy to absorb water, and more water is produced during the composite rolling process. Bubbles, which seriously affect the bonding strength between the alloy layer and the steel back, etc.

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