Gypsum model precise casting technology

Abstract

The invention provides a gypsum model precise casting technology and relates to the technical field of casting technologies. The gypsum model precise casting technology comprises the following steps that gypsum slurry is prepared; grouting is carried out, a box frame in which a module is installed is placed into a grouting chamber, then vacuumizing is carried out to 0.05-0.06 MPa, and the slurry is stably poured into the box frame; roasting is carried out, step temperature rise is adopted, and heat is preserved for a certain period of time in each section, so that the temperature of the innerwall and the temperature of the outer wall are consistent; casting and casting cleaning are carried out; and after a gypsum model is dried completely, gravity casting is carried out, and for large thin-wall precise castings, great careful clearing, repairing and correcting are carried out after casting. According to the gypsum model precise casting technology, the crack risk of the castings can bereduced greatly, size precision is high, the casting cost is low, the casting quality is good, and defects of air holes, shrinkage holes, shrinkage depression, rising and the like are avoided.

Description

technical field [0001] The invention relates to the technical field of casting technology, in particular to a gypsum type precision casting technology. Background technique [0002] Adding fillers to gypsum can significantly reduce the shrinkage of gypsum during high-temperature roasting, enhance crack resistance, and improve thermal conductivity. At the same time, adding 50% cheap fillers to gypsum can also reduce the cost of gypsum. The filler should have suitable melting point, refractoriness, good chemical stability, suitable linear expansion rate, small gas generation and hygroscopicity and other properties. [0003] If only fillers are added to the gypsum mixture, the residual strength of the gypsum mixture after roasting is low, the setting time is not suitable, the collapsibility of the gypsum mixture is poor during cleaning, and the linear expansion rate is not very ideal. The crack tendency is difficult to eliminate. [0004] Although gypsum casting can obtain hi...

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Problems solved by technology

[0003] If only fillers are added to the gypsum mixture, the residual strength of the gypsum mixture after roasting is low, the setting time is not suitable, the collapsibility of the gypsum mixture is poor during cleaning, and the linear expansion rate is not very ideal. The crack tendency is difficult to eliminate

[0004] Although gypsum casting can obtain high-precision molds, a gypsum casting is performed on the basis of CNC machining prototypes, which increases the process flow and increases the difficulty of precision control

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