TC16 and TC4 titanium alloys, developed by the Institute of Metal Research, Chinese Academy of Sciences, are the main materials for aircraft fasteners.The TC16 titanium alloy wires in China under the condition of shear strength meet the requirements of plastic is difficult to achieve lower cold heading problem, through the system study of TC16 wire tensile strength, shear strength - cold heading process performance "three key performance matching relations, proposed the shear strength criterion, and determined the fine grain on top is meet the requirements of cold heading wire comprehensive performance index of the best groups;Then the deformation heat treatment process was designed to obtain the uniform distribution of fine grain basket structure. In addition, the impurity element O is used as microalloying strengthening element to improve the strength level of wire and fastener on the premise of guaranteeing the plasticity and process property. Finally, qualified TC16 titanium alloy cold heading wire was developed for the first time in China.
In order to solve the problems of low strength, uneven microstructure and properties and poor stability of domestic TC4 alloy wire, the impurity element O was used as microalloying strengthening element, and the microalloying element Fe was used to significantly improve the hardenability of TC4 alloy, and solve the problems of poor hardenability and insufficient strength of TC4 fasteners.
Developed with independent intellectual property rights of inline even GaXian three-roller Y type, combined with the optimization of control rolling technology, won the uniform TC4 annealed wire, small groups such as axis, and effectively controls the lateral texture silk material, greatly improve the performance of silk material of hot upsetting technology, and greatly improve the uniformity of the microstructure and mechanical properties of wire, consistency and stability.