Precision casting silica sol shell preparation process

Abstract

The invention relates to a precision casting silica sol shell preparation process. The process comprises a three-layer semi-preparation process of a surface layer, a transition layer, a back layer anda slurry sealing layer, so that the number of coating layers can be reduced, and the shell preparation period can be obviously shortened; and meanwhile, silica sol and zircon powder are adopted as surface layer slurry, 80-120-mesh mullite sand is spread, and transition layer slurry is prepared from silica sol and mullite powder according to the mass ratio of 1:(3.4-3.6). The shell prepared by combining the mesh number of the mullite sand, the slurry viscosity, temperature and humidity control and the like has excellent high-temperature strength without influencing the air permeability, and the process can be used for preparing shells of various products, and is low in cost. According to the process, the surface layer slurry is prepared from silica sol, zircon powder, a wetting agent and adefoaming agent, the mass ratio of the silica sol to the zircon powder is 1:(2.8-3.0), and the viscosity is 35-45 seconds; and the transition layer slurry is prepared from silica sol and mullite powder according to the mass ratio of 1:(3.4-3.6), and the viscosity is 28-35 seconds.

Description

technical field [0001] The invention belongs to the technical field of investment casting, and in particular relates to a process for manufacturing a precision casting silica sol mold shell. Background technique [0002] Investment casting, also known as lost wax casting, refers to making a model with wax, wrapping multiple layers of refractory materials, binders, etc. on the outside, heating the wax to melt and flow out, so as to obtain an empty shell formed by refractory materials, and then The molten metal is poured into the hollow shell, and the casting is obtained after cooling. As a high-quality water machine binder, silica sol is widely used in the preparation of investment casting precision casting shells. The shells prepared by it have good high-temperature strength, strong high-temperature deformation resistance, and stable performance. However, the precision casting silica sol shell process There are defects of high cost and long shell-making period. [0003] Ch...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned patented technology is based on the wax model, and forms 7 layers of reinforcement layers on the basis of the wax model through the method of grouting-sprinkling mixed sand-hardening-drying, and finally seals the grout. The shell-making cycle is long, and each layer uses Mixed sand containing zircon sand, which is very expensive