On the basis of developing and perfecting conventional processes, new process methods have been developed to further improve the quality of castings, increase production efficiency, and expand the application range of investment casting. "Casting", No. 6 of 1978, reported that the Beijing Oil Pump Oven Factory uses a cage-type combination module process. The cage-shaped components ensure sufficient rigidity of the module and double as a gating system, and the utilization rate of molten steel is increased by about 10%. 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 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 electrophoresis 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. There are few electrophoresis shelling processes and a short production cycle. 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 producers of investment casting titanium alloys. "Casting", No. 2, 1979, published in Shanghai Iron and Steel Research Institute, using propane to crack under high temperature vacuum, and the process of producing graphite casting by vapor deposition of graphite on the surface of ethyl silicate hydrolyzate. 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 obtained shell with good strength and gas permeability to produce titanium alloy. High-speed pressurized blades. Shenyang Foundry Research Institute published in the third article of "Casting" in 1986, introducing ZTS-1 resin and toner into coating, p-toluenesulfonic acid as curing agent, and graphite sand and ethanol to form coated sand. The method for producing titanium alloy castings by high-temperature roasting and vacuum processing of the shell and shell. The casting, published in the seventh issue of 1987, published an article by Li Bangsheng, using zirconia ceramic powder and zirconium sol as binder to prepare coatings. , Preparation of shells, research on titanium alloy investment casting production.