Research Of Magnesia Ecological Environmental Protection Moulding Material

With the development of the castings technology and the continuous improvement of thecasting quality requirements, the traditional moulding material is becoming more difficult tomeet the demands of the casting industry.To adapt the trends of the “green casting”, it isnecessary to establish the moulding material system and use low-cost, non-toxic,non-polluting and easy recovery of new material. Therefore, selection of moulding materialsand application of moulding materials technology has become the top priority of castingindustry.This paper aims at studying the low-cost and environmentally friendly mouldingmaterials. On the basis of traditional processes, we have developed these technologies workwith them, and the process properties of the product are tested. This new technology can beused to produce high dimension accuracy, low surface roughness, organizations dense,without any casting defects, excellent properties castings. The article makes an approach tothe basic formulation of Magnesia sand and the casting technology through orthogonalexperiment. Effects content of Magnesium chloride solution, magnesium oxide, the modifier,on moulding sand property were discussed. Capability testing of the optimized magnesia sandwas conducted, and pouring experiment was also made. The best basic formulation ofMagnesia sand is made of raw sand content at100, the Magnesium chloride solution contentat50%, magnesium oxide content at5%, the modifier content at0.5%.The functions of theoptimized moulding sand contented the requirements of moulding sand, the compressivestrength is2.218Mpa, the tensile strength is0.352Mpa, the air permeability is135.5, the gasevolution is23, the surface stability is99.25%, and the use of time is45min. The productiontests to abtain castings are free of surface defect, contours clear and good surface finishingMoreover, this article researched the preparing material and processing technology ofnew-type lost foam casting composite shell, analyzed the performance of different coating,systematically discussed the impact of relevant components on the performance of compositeshell, and analyzed comparatively the surface quality and performance of different shells. Theresults show that using the full closing shell heating can improve the peffect of losepattern.The optimal shrinking temperature is140~160℃. The three-layer compound thin-shellwas adopted with solution ratio at3.0, viscosity at45s of silica sol as surface coating，solution ratio at1.2, viscosity at40s of Oxygen magnesium chloride coatings as transitionalcoating，as well assolution ratio at2.8, viscosity at26s of silica sol as back-up coating toobtain the optimum compound shell.This composite shell has many advantages as follows:simple manufacturing process, short production term, good surface quality and higherstrength at atmospheric temperature than the silica sol shell. The high temperature strength accounted for71%of the silica sol shell, but the retained strength is low. The composite shellcan be completely used in Aluminum alloy and Magnesium alloy satisfying the requirementsof pouring.This article also researched the material formula and processing technology of insultingfeeder.The process and formula were optimized through tests. Effects of raw materials content,and other additives on its property were discussed. The best formula and preparing processwere ascertained. It was successful to manufacture insulting feeder, and was applied in theproduction site. Additionally, the test of field test is carried out, the results of which arecompared with Dalian Jiche resin sand insulting feeder analysis.The experimental results demonstrate that insulting feeder can use recycled foampolystyrene foam particles as insulation material. The optimum quantity of foam ball additiveis5.5%. Addition of industrial dust improved heat preserving effect. The heat preservation ofthe new-type insulatingfeeder is better than the ordinary insulting feeder. Materials which areused to manufacturing insulating riser sleeve are low prices, and produce process is relativelysimple, excellent performance, broad application prospects.