How to correctly carry out subsequent treatment for titanium castings?How to correctly carry out subsequent treatment for titanium castings?
Titanium castings are materials with high strength, lightweight, and excellent corrosion resistance, widely used in fields such as space and aerospace, shipbuilding, automotive industry, and medical equipment. Titanium castings require a series of subsequent treatment processes after casting to improve their mechanical properties, surface quality, and corrosion resistance.
1、 Removing the surface oxide film of titanium castings can easily form an oxide film in air, which can have adverse effects on the subsequent treatment process. Therefore, it is necessary to remove the surface oxide film. The commonly used methods for de oxidation include:
Mechanical oxidation removal: The surface oxide film is ground or polished by mechanical means, and commonly used grinding materials include grinding wheels, sandpaper, etc.
Chemical de oxidation: Chemical solutions are used to dissolve the surface oxide film. Common acidic de oxidation solutions include nitric acid, hydrochloric acid, and sulfuric acid.
2、 Heat treatment is one of the core processes for subsequent treatment of titanium castings, with the main purpose of improving the mechanical properties and microstructure of the castings. The commonly used heat treatment processes include aging treatment, annealing treatment, and normalizing treatment.
Aging treatment: Keep titanium castings at a certain temperature for a period of time to form a stable grain boundary structure inside the crystal, improving the strength and hardness of the material.
Annealing treatment: After heating the titanium casting to a certain temperature, the cooling rate is adjusted to form a uniform and fine grain structure inside the crystal, improving the toughness and plasticity of the material.
Normalization treatment: After heating the titanium casting to a certain temperature, maintain it for a period of time, and then cool it to room temperature. By changing the internal structure of the crystal, adjust the hardness and strength of the material.
3、 Mechanical processing of titanium castings usually requires mechanical processing to achieve the required size and shape. The mechanical processing process mainly includes milling, turning, drilling, reaming, and grinding processes. In the machining process, it is necessary to choose appropriate cutting speed, cutting depth, and cooling method to ensure the machining quality and dimensional accuracy of titanium castings.
4、 The surface treatment of titanium castings mainly includes processes such as polishing, sandblasting, and anodizing. Surface treatment can improve the surface quality and aesthetics of titanium castings, while increasing their corrosion resistance.
Polishing: Using mechanical or chemical methods to remove burrs and roughness from the surface of titanium castings, achieving a smooth surface.
Sandblasting: By using high-pressure gas to spray sand particles onto the surface of titanium castings, the oxide film and uneven surface are removed to obtain uniform surface quality.
Anodizing: Immerse titanium castings in acidic electrolyte, apply current to form a layer of oxide film on their surface, improve corrosion resistance and surface hardness.
5、 After the subsequent processing of titanium castings is completed, a series of quality inspections are required to ensure that they meet the design and usage requirements. The commonly used quality inspection methods include appearance inspection, dimensional measurement, mechanical performance testing, and chemical composition analysis.
6、 After the subsequent processing is completed, titanium castings need to be stored and transported to avoid further oxidation and mechanical damage. During storage and transportation, attention should be paid to maintaining a dry environment, avoiding contact with other materials, and avoiding vibration and collision.
