Magnesium oxide is a kind of embedding material developed for the characteristics of large reaction between quartz embedding material and molten titanium. Its outstanding advantage is that the casting surface is smooth and clean, with minimal pollution. The increase of surface hardness of titanium castings is due to the absorption of oxygen, and the increase of hardness of castings made of magnesium series embedded materials is lower than that of phosphate series. This kind of embedding material usually uses high-purity fused magnesium oxide as the bone material, and used phosphate or ethyl orthosilicate as the binding agent. Nowadays, most of the binders are aluminum oxide. After mixing with water, the hardening time is suitable, the operation performance is good, and the demoulding is good.
The results show that the surface roughness, Vickers microhardness, casting tensile strength and casting flow rate of pure titanium castings cast with magnesium oxide and traditional phosphate-bonded silica embedded materials are better than those of phosphate-bonded silica embedded materials, and magnesium oxide will not affect the surface properties of pure titanium castings. The experiment shows that the magnesia embedded material is more suitable for titanium casting than the silica embedded material. At the casting temperature of 800 ℃, the thermal expansion rate of magnesia embedded material is close to that of silica embedded material.
Through similar comparative experiments, it is found that the pure titanium castings cast with magnesia embedded materials are more accurate and dense than those with quartz embedded materials. Three kinds of titanium alloys were cast with magnesium oxide embedment at 200 ℃. The results showed that the test results of yield strength, tensile strength, elastic modulus and ductility of castings were very ideal.
Compare the four kinds of embedding materials: Remaritan Plus, Bellavest T, Titanium vest, and Titanvest CB; The argon arc casting machine was used for casting, and the relationship between the casting accuracy and the gas permeability of the embedded material was studied and analyzed. It is found that the Bellavest T embedded material with the worst gas permeability is not completely cast, while the Titanvest CB casting with the best permeability is intact and accurate. Titavast CB belongs to MgO system, and the other three belong to quartz system.
According to the scanning electron microscope observation results, it is found that the MgO particles in the Titavest CB embedded material present a highly dense state, which is easier to agglomerate than the SiO2 embedded material, forming a large number of gaps and small spherical holes, which is helpful to discharge the argon in the mold cavity through the embedded material, so as to prevent the high pressure from causing gas backflow and thus affecting the pouring of molten metal.
Yingkou Xinhuafeng Magnesium Products Co., Ltd. is engaged in large-crystal fused magnesia, high-purity magnesia, and electrical-grade magnesium oxide. Welcome to inquire!
+86-13941724528
+86-13941732978
Telephone:
+86-13941724528
contacts:
Jin Feng
Telephone:
+86-13941732978
contacts:
Jin Bing
Address:
Guantun Town, Dashiqiao City, Yingkou City, Liaoning Province
