What heat treatment steps are required for medical titanium rods to improve their mechanical properties and corrosion resistance after machining? During the heat treatment process, how to strictly control the heating rate, holding time and cooling rate to avoid adverse effects such as grain growth and oxidation?

Heat treatment steps for medical titanium bar
Stress relief annealing is the first step in the heat treatment of medical titanium rods, which aims to eliminate or reduce the internal stress generated during cold processing (such as machining). This step is essential to prevent chemical erosion and deformation of the workpiece during subsequent use or special environments. Usually, the titanium rod is heated to a certain temperature (below the recrystallization temperature), kept warm for a period of time and then slowly cooled. During the production process, Changzhou Bokang Special Material Technology Co., Ltd. strictly controls the heating rate and holding time of this step to ensure that the internal stress is effectively eliminated while avoiding adverse effects on material properties.
Full annealing, also known as recrystallization annealing, is another important step in the heat treatment of medical titanium rods. By heating to above the recrystallization temperature, keeping warm for a period of time and then cooling, a stable metal microstructure can be obtained, thereby improving physical properties and improving the stability of workpiece size and performance.
Solution treatment and aging treatment
Solution treatment is a heat treatment process in which the titanium bar is heated to a high-temperature single-phase region, the excess phase is fully dissolved, and then rapidly cooled to obtain a supersaturated solid solution. This step prepares for the subsequent aging treatment so that the material can obtain the best strengthening effect. Aging treatment is to heat the workpiece to a certain temperature (lower than the solution treatment temperature) after solution treatment, keep it warm for a certain period of time, and then cool it to decompose the supersaturated solid solution and precipitate a fine, dispersed strengthening phase, thereby improving the strength and hardness of the material.
Parameter control during heat treatment
In the heat treatment process of medical titanium bar, strict control of heating rate, holding time and cooling rate is crucial to avoid adverse effects such as grain growth and oxidation. Changzhou Bokang Special Material Technology Co., Ltd. has accumulated rich experience in production practice and formed the following effective control strategies:
Excessive heating rate may cause excessive thermal stress inside the titanium rod, and even cause cracking. Therefore, a gradual heating method is adopted to ensure that the temperature inside the titanium rod rises evenly. According to the size, shape and material of the titanium rod, the heating speed is adjusted reasonably to avoid uneven organization caused by excessive temperature difference.
Too short holding time may lead to incomplete organization transformation and affect the heat treatment effect; too long holding time may lead to grain growth and reduce the mechanical properties of the material. According to the material, heat treatment type and required organization state of the titanium rod, the holding time is accurately calculated, and the furnace temperature fluctuation is monitored in real time during the holding process to ensure that the organization transformation is sufficient and uniform.
Too fast cooling speed may cause excessive cooling stress in the titanium rod and even cause cracking; too slow cooling speed may cause coarse organization and reduce the mechanical properties of the material. According to the material and heat treatment requirements of the titanium bar, select the appropriate cooling method (such as water quenching, oil quenching, air cooling or furnace cooling), and strictly control the temperature and flow of the cooling medium to ensure that the titanium rod is cooled at a uniform cooling rate.
Changzhou Bokang Special Material Technology Co., Ltd. has always adhered to the persistent pursuit of high-quality materials in the heat treatment process of medical titanium rods. By accurately controlling heat treatment parameters and strict quality inspection system, it ensures that each medical titanium rod has excellent mechanical properties and corrosion resistance. The medical titanium rods it produces not only have the characteristics of 100% biocompatibility, light weight and high strength, excellent corrosion resistance and excellent fatigue strength, but can also be customized according to customer needs. They comply with international standards such as ISO 5832, ASTM F136, ASTM F67, etc., providing reliable material support for the medical field.