New investment casting process
Categories:Company News
Time of issue:2018-04-21
(Summary description)Based on the development and improvement of conventional processes, new process methods have been developed to further improve the quality of castings, increase production efficiency, and expand the scope of application of investment casting. "Casting" No. 6 in 1978, reported that the Beijing Oil Pump and Oil Nozzle Factory adopts a cage-type combined large module process. The cage-shaped components ensure sufficient rigidity of the module and double as a pouring system.
Based on the development and improvement of conventional processes, new process methods have been developed to further improve the quality of castings, increase production efficiency, and expand the scope of application of investment casting. "Casting" No. 6 in 1978, reported that the Beijing Oil Pump and Oil Nozzle Factory adopts a cage-type combined large module process. The cage-shaped components ensure sufficient rigidity of the module and double as a pouring system. The molten steel utilization rate is increased by about 10%: about. By controlling the solidification time of castings, in-runners and gate rods, Hebei Institute of Technology, etc., make M pieces ≤ M in ≤ M rods and make the solidification stop between the in-runners and gate rods, the liquid state in the gate rods The metal is poured back into the hearth to realize investment casting without gate. In the second casting of 1982, Tsinghua University reported that vacuum suction casting was used to control the solidification time. When the inner sprue solidified and the sprue was not solidified, the vacuum was released and the liquid alloy in the sprue returned to the furnace. The process has strong filling performance, produces thin-walled castings, and has a high molten steel utilization rate. The release of suction casting vacuum is determined according to the thermal conductivity of the mold shell and the solidification time of the suction casting. In the third issue of 1984, Ye Shengyong published an article on electrophoresis shell making. A conductive coating is dip-coated on the wax module. A small amount of chain phosphate is added to the electrophoresis suspension as an electrolyte to make the surface of the refractory material adsorb cations. Under the action of the electric field, the refractory material electrophoreses and accumulates on the surface of the pattern, and An electroosmosis phenomenon occurs, forming a certain strength shell. The electrophoresis shell manufacturing process is few, and the production cycle is short. "Cast" No. 4 in 1984 reported the research on the production of large-scale complex aluminum alloy castings using the gypsum casting process of Northwest Polytechnic University using hemihydrate gypsum, plus quartz powder, quartz glass, and clay as refractory filler. 621 uses hemihydrate gypsum and coal brazing stone as refractory filler to reduce the shrinkage and cracking of the gypsum shell. Titanium and its alloys are important aerospace and petrochemical materials. At the end of the 1970s, investment casting was used to produce titanium alloy castings. my country is one of the five largest investment casting titanium alloy producers in the world. "Casting" published in the second issue of 1979 Shanghai Iron and Steel Research Institute using propane cracking under high temperature vacuum state, vapor deposition of graphite on the surface of corundum (ethyl silicate hydrolysate type shell, titanium alloy investment casting production process. Beihang material The research institute uses phenolic resin as the binder and graphite powder (sand) as the refractory material to produce the graphite shell. It is baked in a vacuum resistance furnace and carbonizes the resin binder to produce a shell with good strength and breathability to produce titanium alloys. High-speed supercharged blades. Shenyang Foundry Research Institute published an article in "Casting" in 1986, introducing the use of ZTS-1 resin and toner to form a coating, p-toluenesulfonic acid as a curing agent, and coated sand with graphite sand and ethanol. ,Moulding shell, high-temperature roasting and vacuum treatment of titanium alloy castings production process. "Foundry" published in the 7th issue of 1987 Li Bangsheng's article, using zirconium oxide ceramic powder, zirconium sol as a binder, to prepare coatings , Preparation of mold shell, production research of titanium alloy investment casting.
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