I. Process Overview The core objective of the titanium alloy surface oxide layer removal process is to quickly and thoroughly remove the oxide layer on the surface of titanium and titanium alloys. This process needs to effectively remove the oxide film while ensuring that the metal substrate is not damaged, restoring its original cleanliness and luster, thereby providing ideal surface conditions for subsequent processing steps such as mechanical processing and surface coating. A high-quality oxide layer removal process should have the characteristics of high efficiency, stable effect, and environmental friendliness. High efficiency means that the oxide layer can be removed in a shorter time, improving production efficiency; stable effect requires that regardless of different batches or shapes of titanium alloy workpieces, the same removal effect can be achieved; environmental friendliness reflects the protection of operators' health and the ecological environment, reducing environmental pollution during the process.
II. Basic Characteristics of the Treatment Agent (1) Physical Characteristics The selected treatment agent is usually a colorless and odorless liquid. This characteristic ensures that operators will not be disturbed by the odor and color during the treatment process, improving the comfort and safety of the operation. Its specific gravity is greater than 1.0, which helps the treatment agent maintain a relatively stable state during heating and use, reducing the possibility of evaporation and splashing. (2) Chemical Characteristics The pH value of the treatment agent is less than 7.0, and it is acidic. The acidic environment can react chemically with the oxide layer on the surface of titanium alloys, causing it to dissolve and achieve the purpose of removal. At the same time, the treatment agent must remain in its original liquid state and cannot be diluted with water. This is because dilution may change the chemical composition and reaction activity of the treatment agent, affecting its removal effect of the oxide layer, and even possibly failing to meet the expected processing requirements. For example, certain specific chemical components may not react fully with the oxide layer after dilution, or the reaction speed may slow down, thereby reducing processing efficiency. (3) Usage Requirements This type of treatment agent needs to be used under professional guidance, such as Titanium Alloy Oxide Layer Removal Agent Q/YS.928 - 4. This is because the treatment agent has certain chemical activity and corrosiveness. If used improperly, it may cause excessive corrosion to the titanium alloy substrate, affecting the dimensional accuracy and mechanical properties of the parts, and also posing a threat to the health and safety of the operators. Professional guidance can ensure that operators correctly master the usage methods, processing time, and temperature and other key parameters of the treatment agent, thereby ensuring the processing effect and safety.
III. Standard Operating Procedures (I) Solution Preparation Heat the treatment agent solution to around 100°C. The purpose of heating is to accelerate the chemical reaction between the treatment agent and the oxide scale, thereby improving the cleaning efficiency. The heating container should be made of thick plastic or heat-resistant ceramic, glass materials. This is because the treatment agent may cause corrosion to the container during the heating process, and thick plastic, heat-resistant ceramic, and glass materials have good corrosion resistance and heat resistance, ensuring the safety and stability of the heating process. If a metal container is used, the treatment agent may react with the metal, not only corroding the container but also changing the chemical composition of the treatment agent, affecting the treatment effect. (II) Soaking Treatment Completely immerse the titanium alloy workpiece in the hot solution. During the soaking process, to ensure uniform reaction, the workpiece can be gently turned. Turning the workpiece can enable the treatment agent to better contact all surfaces of the workpiece, avoiding incomplete treatment in certain areas. For example, for complex-shaped workpieces, such as parts with holes or grooves, if not turned, the oxide scale on these parts may not be completely removed. The soaking time needs to be reasonably controlled based on the material of the workpiece, the thickness of the oxide scale, and the performance of the treatment agent. Generally, for thicker oxide scales or larger workpiece sizes, the soaking time may need to be appropriately extended; conversely, for thinner oxide scales or smaller workpiece sizes, the soaking time can be appropriately shortened. (III) Cleaning After the oxide scale is completely removed, remove the workpiece and thoroughly rinse it with clean water. The purpose of cleaning is to remove the remaining treatment agent and reaction products on the workpiece surface, preventing them from having adverse effects on subsequent processing. Thorough rinsing can ensure that the workpiece surface is clean without residues, providing a good foundation for subsequent processes. For example, if there are residues of the treatment agent on the workpiece surface, during electroplating processing, it may affect the bonding force between the coating and the base material, causing the coating to fall off; during coating processing, it may affect the adhesion and quality of the coating. IV. Safety and Operating Specifications (I) Operating Environment The operation process should be carried out in a well-ventilated area. Because the treatment agent may emit some harmful gases, such as acidic gases, during heating and use. A well-ventilated area can promptly discharge these harmful gases outside, reducing the risk of operators inhaling harmful gases and ensuring the health of the operators. For example, if the oxide scale removal operation is carried out in a sealed space, harmful gases are prone to accumulate, causing operators to experience symptoms such as dizziness and nausea, and in severe cases, even endangering life. (II) Personal Protection Operators should avoid contact of the solution with the skin. The treatment agent has certain corrosiveness. If it comes into contact with the skin, it may cause skin burns, allergies, etc. Therefore, operators should wear personal protective equipment such as protective gloves, protective glasses, and protective clothing during the operation. Protective gloves can prevent the treatment agent from directly contacting the skin; protective glasses can avoid the treatment agent splashing into the eyes, protecting the eyes from harm; protective clothing can prevent the treatment agent from contaminating the clothes and also protect other parts of the body. (III) Waste Liquid Disposal The waste liquid should be treated in accordance with environmental protection regulations. The treatment agent will produce waste liquid containing chemical substances after use. If it is discharged randomly, it may pollute the soil, water sources, etc. Therefore, it is necessary to collect and treat the waste liquid centrally, for example, by neutralization, sedimentation, filtration, etc., to remove or reduce the harmful substances in the waste liquid to below the safe standard before discharging or recycling.
This process is applicable to the precision manufacturing fields that have high requirements for surface quality and working environment, such as aerospace and medical devices. In these fields, the surface quality of titanium alloy products directly affects their performance and service life. Therefore, an efficient, stable and environmentally friendly oxide scale removal process is needed to ensure product quality. At the same time, these fields also have high requirements for the working environment, and strict safety and operation regulations must be followed to ensure the health and safety of operators. The titanium alloy surface oxide scale removal process is a highly technical task. Operators need to strictly follow the process requirements for operation and pay attention to safety and environmental protection. By reasonably selecting treatment agents, mastering standard operation procedures and abiding by safety regulations, the oxide scale on the titanium alloy surface can be effectively removed, providing a good guarantee for the subsequent processing and use of titanium alloy products.