The new investment casting process
Release Time::2014-09-03
Based on the development and improvement of the conventionalprocess, the development of a new technology, further improve thequality of castings, and improve the production efficiency, expand the scope of application of investment casting. "Casting" in 1978 sixth,reports the Beijing oil pump and oil nozzle factory uses squirrel cagecomposite module technology. Each member of the cage type module, to ensure enough stiffness, and as the gating system, improve the utilization rate of 10% steel: left. Hebei Institute of the solidification time control of castings, gate, gate stick, so that M ≤ M ≤ M bar, and thesolidification between cutoff in the sprue and runner bars, liquid metalgate stick in the tilt down cylinder, without pouring investment casting.1982 the second period "casting" report Tsinghua University usesvacuum suction casting filling, solidification time, solidification, includingvacuum lift sprue sprue is not solidified,, sprue liquid alloy return furnace.The process of filling performance is strong, the production of thin-walled castings, steel and high utilization rate. Remove vacuum suction casting,according to the type of shell thermal conductivity and suction castingsolidification time determination. "Casting" in 1984 third periodical published Ye Shengyong's article introduces electrophoretic making shellprocess. Dip coating conductive coating on a wax model group, adding a small amount of chain phosphate electrophoretic suspension as electrolyte, the surface adsorption of refractory cation, under the action of the electric field, occurrence of electrophoresis refractory material,product to appearance on the surface, and the occurrence ofelectroosmosis, shell formed a certain strength. Electrophoretic making shell less process, short production period. "Casting" in 1984 fourthperiod report Northwest University using hemihydrate gypsum, castingplaster external quartz powder, quartz glass, clay refractory fillers,research and produce large and complex aluminum alloy casting. The 621 semi hydrated gypsum, coal drill stone as refractory filler, reducing the plaster mold shell shrinkage, reduce cracking. Titanium and its alloys are important materials used in aerospace, petrochemical in twentieth Century at the end of the 70's began using investment casting of titaniumalloy castings, China is one of the titanium alloy investment castingproduction country in the five world. "Casting" in 1979 second issue of Shanghai Iron & Steel Research Institute by the cracking of propane at high vacuum condition, the corundum (hydrolyzed ethyl silicate mold shell surface vapor deposition process of graphite, titanium alloy investment casting production. Study of BUAA materials for phenolic resin as binder, Shi Mofen (sand) for production of graphite shellrefractories, baking in vacuum resistance furnace, carbonized resinbinder, produce good strength and breathable shell of titanium alloy production, high speed turbo blade. Shenyang Foundry Research Institute "casting" in 1986 third published articles, introduced the ZTS-1resin and toner with paint, p-toluene sulfonic acid as a curing agent, and the graphite sand, ethanol preparation of coated sand, making shell,shell calcination and vacuum processing production of titanium alloy casting process. "Casting" 1987 the seventh period published Li Bangsheng, the zirconia ceramic powder, zirconium sol as binder,coating, preparation of shell, for the production of titanium alloy investment casting.