Shenzhen Wuge Industrial Co., Ltd

The processing flow of nickel titanium pipes generally includes the following main steps:

1、 Raw material preparation

(1) Choose suitable nickel titanium alloy materials: Based on usage requirements, select nickel titanium alloy rods or tubes with specific composition and properties as billets. Attention should be paid to the purity, mechanical properties, shape memory characteristics, and other indicators of the material to ensure that it meets the processing and usage requirements.

(2) Inspect the quality of raw materials: Conduct strict quality inspections on purchased raw materials, including chemical composition analysis, hardness testing, metallographic structure inspection, etc., to eliminate unqualified materials and avoid problems in subsequent processing.

2、 Cutting and cutting materials

(1) Determine cutting length: Based on the specifications and dimensions of the required nickel titanium tube, calculate and determine the cutting length of the billet, while considering the machining allowance to ensure the dimensional accuracy of the final product.

(2) Choose cutting method: Common cutting methods include sawing, laser cutting, electric discharge cutting, etc. Sawing is suitable for larger diameter pipes, with high cutting efficiency, but the cutting surface may be rough; Laser cutting and electric discharge cutting have the advantages of high cutting accuracy, narrow incision, and small heat affected zone, and are suitable for cutting high-precision and small-sized nickel titanium pipes.

3、 Forming processing

(1) Cold drawing or cold rolling: For some nickel titanium pipes that require high-precision dimensions and good surface quality, cold drawing or cold rolling processes are often used. By placing the billet into the mold and using external force to pass it through the mold hole, the diameter and wall thickness of the pipe can be reduced, thereby achieving the desired size and shape. Cold drawing and cold rolling can improve the strength and surface smoothness of pipes, but attention should be paid to controlling the processing speed and deformation during the processing to avoid cracks or other defects in the material.

(2) Hot extrusion: For some nickel titanium tubes with complex shapes or large sizes, hot extrusion is a commonly used forming method. Place the billet heated to a certain temperature into the extrusion cylinder, apply pressure through the extrusion rod, and extrude the material from the mold hole to form the desired shape of the pipe. Hot extrusion can improve the internal structure of materials, enhance their density and mechanical properties, but it requires specialized heating equipment and extrusion molds, and the processing cost is relatively high.

4、 Heat treatment

(1) Stress relief annealing: During the forming process, residual stress may be generated inside the nickel titanium tube, which may affect the dimensional stability and mechanical properties of the tube. By stress relief annealing treatment, the pipe is heated to an appropriate temperature and held for a certain period of time, and then slowly cooled to release internal stress, improving the dimensional stability and toughness of the pipe.

(2) Shape memory heat treatment: In order to achieve good shape memory effect on nickel titanium tubes, specialized shape memory heat treatment is required. Usually, the pipe is heated to a higher temperature and then cooled at a specific cooling rate. By adjusting the heat treatment process parameters, the phase transition temperature and shape memory performance of nickel titanium alloys can be controlled.

5、 Surface treatment

(1) Acid washing: Acid washing is a common method for removing oxide scale and impurities on the surface of nickel titanium pipes. Soak the pipe in an acidic solution and dissolve the surface oxide layer through a chemical reaction, exposing the metallic luster on the surface of the pipe. After acid washing, the pipe should be thoroughly rinsed with clean water to remove residual acid and prevent corrosion of the pipe.

(2) Electrolytic polishing: Electrolytic polishing can further improve the surface smoothness and corrosion resistance of nickel titanium pipes. Using the pipe as an anode, it is placed in an electrolytic polishing solution, and the micro protrusions on the surface of the pipe are preferentially dissolved through electrolysis, thereby achieving a smooth and flat surface effect. Electrolytic polishing can not only improve the appearance of pipes, but also reduce surface roughness, lower the possibility of bacterial adhesion and dirt accumulation, and is suitable for some application fields that require high surface quality, such as medical devices.

6、 Dimensional accuracy and performance testing

(1) Dimensional accuracy measurement: Measuring tools such as calipers, micrometers, coordinate measuring instruments, etc. are used to accurately measure the outer diameter, inner diameter, wall thickness, length, and other dimensions of nickel titanium pipes to ensure that they meet the tolerance range required by the design. Any dimensional deviation beyond the tolerance may affect the performance and assembly accuracy of the pipe in subsequent use.

(2) Mechanical performance testing: By using methods such as tensile testing, hardness testing, and bending testing, the mechanical properties of nickel titanium pipes are tested, including tensile strength, yield strength, elongation, hardness, and other indicators. These performance indicators are directly related to the load-bearing capacity and reliability of the pipe during use.

(3) Shape memory performance testing: Using specialized testing equipment, the shape memory effect of nickel titanium pipes is tested, such as measuring parameters such as shape recovery rate and phase transition temperature of the pipes during heating and cooling processes. Shape memory performance is one of the important characteristics of nickel titanium tubes, which is crucial for their performance in specific application fields.

7、 Packaging and Storage

(1) Packaging: Qualified nickel titanium pipes are packaged using plastic film, paper boxes, wooden boxes, and other packaging materials to prevent damage, corrosion, or contamination during transportation and storage. For some high-precision or special requirements of pipes, vacuum packaging or packaging filled with protective gas may be necessary to further improve the preservation quality of the pipes.

(2) Storage: Store the packaged nickel titanium pipes in a dry, ventilated, temperature and humidity suitable warehouse, avoiding contact with corrosive substances such as acids, alkalis, salts, etc., and preventing mechanical collision and compression to ensure stable quality of the pipes during storage.