Process of titanium castings for subsequent treatment

Titanium casting is a material with high strength, light weight and excellent corrosion resistance, which is widely used in space aerospace, shipbuilding, automotive industry, medical equipment and other fields. Titanium castings need a series of follow-up treatment processes after casting to improve their mechanical properties, surface quality and corrosion resistance.
First, remove the casting surface oxide film Titanium castings in the air is easy to form an oxide film, for the subsequent treatment process will have a negative impact, so the need to remove the surface oxide film. Commonly used to oxidize methods are:
Mechanical de-oxidization: mechanical way to the surface of the oxide film grinding or polishing, commonly used grinding materials such as grinding wheels, sandpaper.
Chemical de-oxidation: the use of chemical solutions to dissolve the surface oxide film, commonly used acid de-oxidation solution has nitric acid, hydrochloric acid and sulfuric acid.

Second, heat treatment Heat treatment is one of the core process of titanium casting follow-up treatment, the main purpose is to improve the mechanical properties and organizational structure of the castings. Commonly used heat treatment processes are aging treatment, annealing treatment and normalizing treatment.
Aging treatment: titanium castings are kept at a certain temperature for a certain period of time, so that they form a stable grain boundary structure within the crystal, and improve the strength and hardness of the material.
Annealing treatment: the titanium castings are heated to a certain temperature, by adjusting the cooling rate, so that the formation of uniform fine grain structure within the crystal, improve the toughness and plasticity of the material.
Normalizing treatment: After the titanium castings are heated to a certain temperature, they are kept for a period of time and then cooled down to room temperature, so as to adjust the hardness and strength of the material by changing the internal structure of the crystals.
Third, mechanical processing Titanium castings usually need to be machined to achieve the required size and shape. The machining process mainly includes milling, turning, drilling, reaming and grinding. In the machining process, you need to choose the appropriate cutting speed, depth of cut and cooling to ensure that the machining quality and dimensional accuracy of titanium castings.
Fourth, surface treatment The surface treatment of titanium castings mainly includes polishing, sandblasting and anodizing processes. Surface treatment can improve the surface quality and aesthetics of titanium castings, while increasing its corrosion resistance.
Polishing: the use of mechanical or chemical methods to remove burrs and roughness on the surface of titanium castings, to obtain a smooth surface.
Sandblasting: Remove oxidized film and uneven surface by spraying sand onto the surface of titanium castings through high-pressure gas to obtain a uniform surface quality.
Anodizing: Titanium castings are immersed in acidic electrolyte and current is applied to form a layer of oxide film on the surface to improve corrosion resistance and surface hardness.
Five, quality inspection After the completion of the follow-up treatment of titanium castings, a series of quality testing needs to be carried out to ensure that it meets the design requirements and use requirements. Commonly used quality inspection methods are appearance inspection, size measurement, mechanical properties test and chemical composition analysis.
Sixth, storage and transportation Titanium castings in the follow-up treatment is completed, need to be stored and transported, in order to avoid re-exposure to oxidation and mechanical damage. In the process of storage and transportation, need to pay attention to maintain a dry environment, avoid contact with other materials and avoid vibration and collision.