A copper-based graphite self-lubricating composite part for low speed and heavy load and its manufacturing method

Abstract

The invention discloses a manufacturing method of a copper-based graphite self-lubricating composite member for low-speed heavy loads. The composite member is composed of a copper alloy matrix and a graphite column, wherein a copper alloy is composed of Cu, Sn, Al2O3 and Zn. A graphite mold core green body comprising a graphite column and a graphite matrix is prepared, and the graphite mold core green body is subjected to secondary curing, carbonization, multiple impregnation of silica sol and high temperature sintering aftertreatment to obtain a graphite mold core prefabricated body; and finally, the graphite mold core prefabricated body is placed in a synthetic graphite cast mold to be fixed, and lubricating oil is impregnated into micro-holes inside the graphite column under the vacuumpressure condition to obtain the copper-based graphite self-lubricating composite member. By means of the method, while local compounding of the graphite column and the copper alloy is quickly realized, good interface bonding between the copper and the graphite is ensured, and the prepared copper-based graphite self-lubricating composite member has the beneficial effects of the strong bearing capacity, the good lubricating effect, wear resistance and the like and can be used for producing ship lock bottom pivot ball bearings, large mining mechanical ball bearings and the like.

Description

technical field [0001] The invention relates to a method for manufacturing a copper-based graphite self-lubricating composite part for low-speed and heavy-duty use, which belongs to the technical field of near-net shape manufacturing, and specifically relates to a rapid manufacturing method for a high-strength copper alloy and graphite composite part. As a self-lubricating part, it is applied to low-speed heavy-duty load working environment. [0002] technical background [0003] At present, the friction pair of the bottom pivot of the miter door and triangular door ship lock is generally a ball bearing, which adopts the "soft-hard" combination method, that is, the material of the mushroom head is medium-high carbon steel, and the material of the mushroom cap is high-strength copper alloy. Working at low speed and heavy load for a long time, the most likely problem caused by low speed is that it is difficult to quickly form an effective lubricating oil film, and heavy load pu...

AI Technical Summary

Problems solved by technology

At present, the composite processes of copper alloy and graphite mainly include powder metallurgy, mosaic method and mosaic casting method. Powder metallurgy method is widely used, but due to the large difference in density between copper powder and graphite powder, it is difficult to mix evenly, and it is also difficult to accurately control the graphite in the process. The distribution range in the copper matrix. In addition, the two are "integrated" together under high temperature and high pressure conditions. The content and distribution of graphite have a great influence on the strength of the copper alloy matrix.

The mosaic method needs to groove or drill holes in the copper alloy substrate in advance. As mentioned above, this will not only damage the strength of the metal substrate, but also it is difficult to groove or drill holes on the free-form surface, and the processing cost is also high; The synthetic graphite column or graphite cement is embedded in the groove or hole by extrusion, and the bond between graphite and copper alloy matrix is ​​weak

The inlay casting method is to fix the synthetic graphite column pretreated with ethyl silicate on the mold core / foam model, and then inject high-temperature copper alloy liquid to make it "composite" into one, and the interface bonding between the two is improved. "Partial compounding" is beneficial to ensure the strength of the metal matrix, but the positioning operation of graphite columns is difficult and the production cost is also high

[0005] To sum up, in view of the complexity of the structure of the mushroom cap used for the bottom pivot of the ship lock and the particularity of the low-speed and heavy-load working environment, there is currently no effective process method to achieve both the lubrication effect and the metal matrix strength without major damage the goal of

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