Original title: Do you know the surface treatment of titanium and titanium alloy? Titanium is easy to react with O, H, N and other elements in the air and Si, Al, Mg and other elements in the investment at high temperature, and a surface contamination layer is formed on the surface of the casting, so that the excellent physical and chemical properties of the casting are deteriorated, the hardness is increased, the plasticity and elasticity are reduced, and the brittleness is increased. The density of titanium is small, so the inertia of titanium liquid flow is small, and the fluidity of molten titanium is poor, resulting in low casting flow rate. Due to the large temperature difference (300 ℃) between the casting temperature and the mold, the cooling is fast, and the casting is carried out in a protective atmosphere, it is inevitable that there are defects such as pores on the surface and inside of titanium castings, which have a great impact on the quality of castings. Therefore, the surface treatment of titanium casting is more important than other dental alloys. Because of the unique physical and chemical properties of titanium, such as small thermal conductivity, low surface hardness, low elastic modulus, high viscosity, low conductivity and easy oxidation, the surface treatment of titanium is very difficult, and it is difficult to achieve the desired effect by conventional surface treatment methods. Special processing methods and operation methods must be adopted. The later surface treatment of the casting is not only to obtain a smooth and bright surface, reduce the accumulation and adhesion of food and plaque,titanium seamless tube, maintain the normal oral microecological balance of the patient, but also to increase the aesthetic feeling of the denture; More importantly, through these surface treatment and modification processes, the surface properties and suitability of castings are improved, and the physical and chemical properties of dentures, such as wear resistance, corrosion resistance and stress fatigue resistance, are improved. I. Removal of Surface Reaction Layer The surface reaction layer is the main factor affecting the physical and chemical properties of titanium castings. Before the grinding and polishing of titanium castings, the surface contamination layer must be completely removed to achieve satisfactory polishing effect. The surface reaction layer of titanium can be completely removed by the method of acid cleaning after sand blasting. 1. Sand blasting For the sandblasting treatment of titanium castings, it is generally better to use white corundum coarse blasting,ti6al4v eli, and the sandblasting pressure is smaller than that of non-precious metals, which is generally controlled below 0.45Mpa.  The surface pore defect can be directly repaired by laser local welding. III. Grinding and polishing 1． Mechanical grinding: Titanium has high chemical reactivity, low thermal conductivity, high viscosity, titanium plate gr7 ,ti6al4v, low grinding ratio of mechanical grinding, and is easy to react with abrasive tools. Ordinary abrasives are not suitable for grinding and polishing of titanium.In order to prevent the rapid oxidation of titanium at high temperature,titanium round bar, titanium silicon compounds and titanium aluminum compounds are formed on the surface of titanium, which can prevent the oxidation of titanium at temperatures above 700 ℃. This kind of surface treatment is very effective for the oxidation of titanium at high temperature. Perhaps the coating of this kind of compound on the surface of titanium is beneficial to the combination of titanium and porcelain, and further research is needed. More Titanium and Titanium Alloy Surface Treatment Titanium Plate Titanium Anodizing Please Pay Attention to Ruida Titanium Industry Return to Sohu to See More Responsible Editor:. yunchtitanium.com