Titanium is non-toxic, light, high strength and biocompatible. It is an ideal medical metal material, which can be used as implants in the human body. At present, Ti-6Al-4V Eli alloy is still widely used in medical field. However, the latter will precipitate a very small amount of vanadium and aluminum ions, which will reduce its cell adaptability and may cause harm to the human body. This problem has been widely concerned by the medical community for a long time. As early as the mid-1980s, the United States began to develop non-aluminum, non-vanadium, biocompatible titanium rods for orthopedics. Japan, Britain and so on have also done a lot of research work in this area and made some new progress. For example, Japan has developed a series of α + β titanium alloys with excellent biocompatibility, including ti-15zr-4nb ta-0.2pd, ti-15zr-4nb-ta-0.2pd-0.20 ~ 0.05N, ti-15sn-4nb-2ta-0.2pd and ti-15sn-4nb-2ta-0.2pd-0.20. The corrosion strength, fatigue strength and corrosion resistance of these alloys are superior to that of Ti-6Al-4V Eli. Compared with α + β titanium alloy, β titanium alloy has higher strength and water content, better incision performance and toughness, and is more suitable for implantation into the human body. In the United States, five kinds of β - titanium alloys have been recommended to the medical field, namely TMZFTM (ti-12mo - ^ Zr-2fe), ti-13nb-13zr, timetable 21srx (ti-15mo-2.5nb-0.2si), Teradyne 1610 (ti-16nb-9.5hf) and Ti-15Mo. It is estimated that in the near future, this kind of titanium alloy with high strength, low modulus of elasticity, excellent formability and corrosion resistance is likely to replace the Ti-6Al-4V Eli alloy widely used in the medical field.
Titanium alloy is recognized as one of the most difficult materials in the machining industry. Its processing cost is several times to dozens of times of its material value. Let me give you a brief description of one characteristic of titanium alloy, and you can see the difficulty of processing. "Low thermal conductivity", that is to say, slow heat transfer. If the heat transfer is slow, the heat will be accumulated locally and the tool will be burned easily. Therefore, in order not to generate a lot of heat, the cutting speed of the tool is very slow when machining titanium alloy, so the processing time is very long. In order to improve the processing efficiency of titanium alloy, some large factories will use liquid nitrogen for processing cooling. At present, many implant companies have invested a lot of costs in research and development. In the face of different oral conditions, there are many types of implant teeth, and the relevant accessories are many times more. From implant implantation to the final teeth inlay, at least seven or eight kinds of precision accessories should be used. Moreover, some patients need personalized customization, and the related costs are higher. Smaller parts require higher precision. At present, dental implant accessories rank at the top of precision in the medical category. Because of the high cost of the material, the material is made of pure titanium or titanium alloy, which has good biocompatibility, no exclusion with a human body, and can be closely combined with the alveolar bone, strong and durable. This titanium "camouflage" is the prerequisite for the success of the implant. After the implant, whether the bone binding or the fibrous connective tissue wrapping, that is, whether the implant repair is successful or failed, the important factor is the mechanical stability after the implant.