ABSTRACT
BACKGROUND:In recent years,additive manufacturing(also known as 3D printing)has gradually become the mainstream method for producing titanium alloy brackets for removable partial dentures.Heat treatment,as an important method to improve the mechanical properties of 3D printed titanium alloys,has become a current hot topic of attention.OBJECTIVE:To summarize the main heat treatment technologies currently applied to 3D printed titanium alloy specimens(including annealing,solution aging,hot isostatic pressing,and other heat treatments)and their effects on the mechanical properties and microstructure of 3D printed titanium alloy specimens,providing a theoretical basis for improving the heat treatment technology of removable partial denture titanium alloy supports.METHODS:A computer search was conducted on research materials related to 3D printed titanium alloy heat treatment in databases such as CNKI,PubMed,and ScienceDirect.The search period was from 2012 to 2023.A total of 61 articles were selected based on inclusion and exclusion criteria.RESULTS AND CONCLUSION:(1)Using conventional annealing techniques to treat 3D printed titanium alloy specimens,keeping them at 500-900 ℃ for 2-4 hours,can effectively increase the elongation of 3D printed titanium alloy specimens.(2)Compared to conventional annealing techniques,solid solution aging treatment is more complex,and the titanium alloy specimens after solid solution aging treatment exhibit outstanding yield strength and better corrosion resistance.However,the 3D printed titanium alloy specimens after solid solution aging treatment have no advantage in terms of ductility.(3)Hot isostatic pressing treatment can reduce the internal defects of 3D printed titanium alloy specimens,significantly increase the elongation of 3D printed titanium alloy specimens,and increase their fatigue life.(4)Rapid heat treatment can significantly improve the elongation of 3D printed titanium alloy specimens,and the speed is faster.In terms of elongation improvement and heat treatment efficiency,it has more advantages than conventional annealing in the past.(5)The improvement of elongation of 3D printed titanium alloy specimens by cyclic heat treatment exceeds that of conventional annealing.Cyclic heat treatment can significantly improve the grain structure of 3D printed titanium alloy specimens,but the heat treatment time is too long and the efficiency is low.