On the basis of developing and perfecting conventional processes, new process methods have been developed to further improve the quality of precision casting processing, increase production efficiency, and expand the application range of investment casting. "Casting", No. 6 of 1978, reported that the Beijing Oil Pump Ou Tsui Factory uses a cage-type combined large module process. The cage-shaped components ensure sufficient rigidity of the module and double as a gating system. The utilization rate of molten steel is increased by 10%: about. Hebei Institute of Technology, etc., by controlling the solidification time of castings, gates, and gate bars, so that M parts ≤ M ≤ M rods, and solidification is cut off between the gate and the gate rod, the liquid in the gate rod The metal is poured back into the hearth to achieve gateless investment casting. In the second issue of "Casting" in 1982, Tsinghua University and others used vacuum suction casting to control the solidification time. When the inner runner solidified and the sprue was not solidified, the vacuum was released and the liquid alloy in the sprue was returned to the furnace.

The process has strong filling performance and produces thin-walled castings with high utilization rate of molten steel. The release of the suction casting vacuum is determined according to the thermal conductivity of the shell and the solidification time of the suction casting. In the third issue of 1984, Casting published an article by Ye Shengyong on the electrophoretic shell making process. The conductive coating is immersed on the wax module, and a small amount of chain phosphate is added as an electrolyte in the electrophoretic suspension to adsorb the cation on the surface of the refractory material. Under the action of the electric field, the refractory material is electrophoresed and accumulated on the surface of the pattern, and Electroosmosis occurs and a shell of a certain strength is formed. The electrophoresis shelling process is small and the production cycle is short. In the fourth issue of 1984, Casting reported that Northwestern University of Technology used semi-hydrated gypsum, plus quartz powder, quartz glass, and clay as refractory fillers to produce large-scale complex aluminum alloy castings. 621 uses semi-water gypsum and coal-bearing stone as refractory filler to reduce the shrinkage of gypsum shell and reduce cracking. Titanium and its alloys are important aerospace and petrochemical materials. In the late 1970s, titanium alloy castings were produced by investment casting. China is one of the world's top five investment casting titanium alloy producers.

"Casting", No. 2, 1979, published in the Shanghai Iron and Steel Research Institute using propane in high-temperature vacuum to crack, in the corundum (ethyl silicate hydrolyzed liquid shell surface vapor deposition of graphite, titanium alloy investment casting production process. Beihang Materials The research institute uses phenolic resin as binder, graphite powder (sand) as refractory material to produce graphite shell, calcined in vacuum resistance furnace, carbonized resin binder, and obtains shell with good strength and gas permeability to produce titanium alloy. High speed pressurized blades.