Extrusion moulding mold and method in semi-solid state preparation method of aluminium-coating magnesium composite pipe

Abstract

The invention relates to an extrusion moulding mold and method in a semi-solid state preparation method of an aluminium-coating magnesium composite pipe. The inner layer of the composite pipe is made from AZ91S magnesium alloy, and the outer layer of the composite pipe is made from 7075 aluminium alloy. The extrusion moulding method comprises preparation of blank, secondary heating and semi-solid state extrusion moulding, and specifically comprises the following steps: placing prepared aluminium alloy semi-solid state blank and magnesium alloy semi-solid state blank with solid fraction being 70%-90% into an extrusion cavity of an extrusion barrel through a hot charging process, and performing extrusion moulding to obtain the aluminium-coating magnesium composite pipe with the wall thickness of 4-8mm and the length of 1,200-3,000mm, wherein the preheating temperature of the mold is 250-300 DEG C, and the extrusion speed is 60-150mm / s. According to the invention, the bonding interface of the aluminium-coating magnesium composite pipe completely reaches the metallurgical bonding, and compared with other moulding methods, the extrusion moulding method has the advantages of high efficiency, short flow, good pipe quality, simple structure, and simplicity in implementation; the prepared aluminium-coating magnesium composite pipe is small in density, and high in specific strength and specific stiffness, the outer layer is corrosion-resistant, the inner layer is good in shock absorption and shock resistance, and the prepared aluminium-coating magnesium composite pipe is particularly suitable for the fields of manufacturing of baggage holders of high speed trains, seats, portable bicycle frames, high-grade lamps and lanterns, and the like, and has very wide application prospect.

Description

Technical field [0001] The present invention involves an aluminum -magnesium composite control mold and method, especially a squeezing molding mold and method in the semi -solid preparation method of aluminum -packed magnesium composite tube. Background technique [0002] Double -layer composite pipes refer to pipes prepared by the inner and outer layers from heterogeneous metals through certain processing methods. The inner and outer metals have different properties to meet the requirements of different working environments.At present, composite pipes have broad application prospects in multiple fields such as transportation, transportation pipelines, and aerospace.With the rapid development of my country's high -tech and national defense military industry, the demand for composite pipes has continued to increase, and the requirements for product quality are getting higher and higher.Especially in recent years, my country's resources and environmental issues have become increasi...

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Problems solved by technology

Obviously, there are at least two disadvantages in this method: firstly, the production cycle of the process is long, one-time forming cannot be realized, and the energy consumption is high; secondly, the composite pipe produced by welding, the inner pipe and the outer pipe are combined Not tight, the gap and stress between the tubes are easy to cause product failure

[0004]The liquid metal continuous casting composite method can also be used to prepare double-layer composite pipes (see: Su Yajun, Liu Xinhua, Wu Yongfu, etc. Direct composite forming of copper by horizontal continuous casting Microstructure and properties of aluminum-clad composite materials. Special Casting and Nonferrous Alloys, 2011, 31(9):785-789), which belongs to the liquid phase-liquid phase composite method. This forming method is conducive to improving the quality of composite pipes, but there are High equipment investment cost (requires specific casting equipment), high production temperature (processing temperature is above 100°C of the alloy liquidus), low production efficiency (average casting speed is only 60-90mm / min), large energy consumption, production The process is difficult to control precisely (throwing is prone to cracking, overlapping, etc.) and other defects, which limit its application prospects

[0005]In addition, the traditional rolling crimping method and cladding welding method are all solid-solid phase composite methods, which have long production process and cost High environmental burden, difficulty in preparing special-shaped or large-sized composite pipes, and difficulty in achieving metallurgical bonding effects between inner and outer layers (see: Luo Ruixue. Research on Extrusion Forming Technology of Bimetallic Composite Pipes. Thermal Processing Technology, 2010, 39(13):87-89)

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