Preparation method of FD evaporative pattern plate and evaporative pattern plate prepared by preparation method

Abstract

The invention discloses a preparation method of a FD evaporative pattern plate and an evaporative pattern plate prepared by the preparation method. The preparation method comprises the processing steps of selecting of beads, pre-foaming, drying and curing, compression moulding forming, cooling, demoulding, plate drying and the like. According to the preparation method of the FD evaporative patternplate and the evaporative pattern plate prepared by the preparation method, the detects of carbon black on the surface of a nodular iron casting after the nodular iron casting is casted and the likecan be overcome, the gas forming amount can be effectively reduced and reverse spraying in the pouring process can be avoided, the appearance of a manufactured and produced FD evaporative pattern is prevented from deforming, the bonding strength of the beads is improved, sufficient integration of the beads is ensured, and the structural strength of the casting is improved; and the effects of saving raw materials, reducing the cost, and being environmentally friendly are achieved, the yield of castings is greatly increased, and the comprehensive production cost of the casting is further reduced.

Description

technical field [0001] The invention belongs to the technical field of casting, and in particular relates to a method for preparing an FD lost formwork material and the prepared lost formwork material, and is especially suitable for the preparation of a lost form solid plate material of gray iron parts. Background technique [0002] The lost foam casting technology is to bond and combine foamed plastic models similar in size and shape to the castings to form a model cluster. After brushing with a refractory coating and drying, it is buried in dry quartz sand for vibration molding, and liquid metal is poured under certain conditions. The method of vaporizing the model and occupying the position of the model, solidifying and cooling to form the required casting. Compared with traditional casting technology, lost foam casting uses foam materials (EPS, EPMMA, FD and FD-FD) that are easily vaporized at high temperatures as patterns, without sand cores, non-bonded dry sand, unsuit...

AI Technical Summary

Problems solved by technology

Due to the advantages of low price, low gas generation, and easy forming of EPS, the pattern material used by most foundries is generally EPS to produce ductile iron castings, but this material has a relatively high carbon content (up to 92%). And the molecular formula contains a carbon-rich benzene ring structure, which is relatively stable in thermodynamics, so it is not easy to thermally decompose. When the temperature is higher than 900 ° C, EPS is thermally decomposed to form a tar-like viscous liquid, which is further decomposed into carbon and hydrogen. Cracking is carried out in the way of disorderly fracture, so it is easy to produce carbon black on the castings when producing ductile iron, and the castings are prone to defects such as slag inclusions, which will reduce the quality of the castings or even scrap them

[0004] EPMMA is a polymer with a straight-chain structure. When it is thermally decomposed, it will be cracked in a rapid way. The use of EPMMA is very effective in solving defects such as carbon black on the surface of ductile iron castings, but the gas generation of EPMMA is about that of EPS. 1.5 times, it is easy to cause back spray when pouring

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