Application method of a composite phase change material in copper-steel bimetal casting process

Abstract

The invention discloses a method for using a composite phase change material in a copper-steel bimetal casting process, which is to combine molten salt, SiO 2 , stearic acid and borax are mixed and evenly ball-milled, then pressed and sintered to obtain a composite phase change material used in the copper-steel bimetal casting process, wherein the molten salt is composed of KF and MgF 2 mixed. In the method of the present invention, the composite phase change material is placed on the upper layer of the copper alloy, which undergoes a solid-to-liquid transition during casting to absorb and store heat, and undergoes a liquid-to-solid transition during cooling to release the stored heat. , It has a good heat preservation effect on the copper alloy, so that there is a greater temperature difference between the lower layer and the upper layer of the copper alloy during cooling, and the upper layer can achieve a good feeding effect on the lower layer, avoiding the problem of shrinkage and shrinkage.

Description

technical field [0001] The invention belongs to the field of bimetal composite molding, and in particular relates to a method for using a composite phase change material in a copper-steel bimetal casting process. Background technique [0002] Copper-steel bimetallics are widely used in various mechanical parts because of the excellent tribological properties of copper alloys and the advantages of steel in mechanics and machining properties. There are many forming methods for copper-steel bimetal, and the methods widely used in production at present mainly include rolling composite method, powder sintering method, casting composite method, electromagnetic continuous casting method, melting casting method, etc., among which rolling composite method and powder The sintering method generally has the limitation of low bonding strength, which makes it difficult to operate stably under high loads. Casting and electromagnetic continuous casting have problems such as complicated oper...

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Problems solved by technology

[0004] The inorganic salt ceramic-based composite phase change material, which is composed of inorganic salt and ceramic materials, has high melting point of inorganic salt, good thermal stability, large specific heat capacity and latent heat of phase change, adjustable phase change temperature and high temperature resistance of ceramic materials, Low thermal conductivity and corrosion resistance and other performance advantages, if the composite phase change material can be applied to the copper-steel bimetal casting process, the latent heat of phase change absorbed by the phase change of the inorganic salt during heating can be released at a temperature near the liquidus line of the copper alloy In order to strengthen the thermal insulation effect, it may be possible to construct a sequential solidification condition of "the bottom of the copper layer is solidified first, and the upper part of the copper layer is solidified last", so as to achieve a better feeding effect, but there is no relevant report at present, and at present Due to the different application fields of the existing composite phase change materials, the phase change temperature is generally 600-700°C and below, which cannot meet the requirements of the copper-steel bimetal casting process.

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