3D printing titanium alloy for medical use

The global market for bone repair is surging as the world's aging population increases and more cases of bone loss are caused by accidents. In order to improve the quality of life of patients, artificial implants are often used in surgery to replace the failure site of patients. The commonly used metal implant materials in clinical practice generally include titanium alloy, stainless steel and cobalt-chromium alloy, etc., which are mainly used as artificial joints and bone substitutes to replace the damaged or diseased hard tissues of patients. Stainless steel is an early developed metal medical implant material with lower material cost, which used to occupy a large part of the medical metal implant market. However, due to the high density of stainless steel, strong foreign body sense of patients, and poor corrosion resistance of Fe, the Ni and Cr ions released by wear and tear during use have great toxic and side effects on cells, etc., the application scale of stainless steel in the implant market is constantly shrinking. With the development of biomedical alloy, titanium and titanium alloy products with better biocompatibility have been widely used in bone tissue repair in recent years.

At present, the vast majority of medical metal bone implantation products in the market are still produced by mold casting. This kind of method has a small degree of product size differentiation and cannot meet the individual needs of different RACES, genders, ages and individual cases. At the same time, the elastic modulus of metal materials is larger than that of bone, and the combination of metal materials and bone may produce stress shielding phenomenon, while long-term use may lead to osteoporosis in patients, and even cause implant sliding, leading to implant failure. Therefore, in recent years, researchers have tried to use porous materials to reduce the elastic modulus of implants and improve the success rate of implants. Traditional preparation methods of porous materials include powder metallurgy, slurry and fiber sintering, etc., but due to their technical characteristics, the mechanical or biological properties of the materials are more or less affected, so that they cannot meet the requirements of the implant, leading to the slow development of the porous biological implant.

With the continuous development of 3D printing equipment technology, the advantages of using 3D printing technology to manufacture porous medical materials become more and more obvious.3 d printing technology has high machining freedom, for 3 d printing bone materials, it can make use of medical images such as CT, MRI and bone reconstruction in patients with failure model by computer and create biological properties and mechanical properties of implant and bone matching products, more can be unique treatment for each patient, implemented as the status of the patients with bone implant product customization. Because of its layer-by-layer processing characteristics, 3D printing can easily produce various pore sizes and porous materials with bionic effect and biocompatibility, thus improving the bone binding ability of implants. Therefore, 3D printing has great application potential in the medical field.