Processing characteristics of medical titanium and titanium alloys

Titanium has good biocompatibility, so it is selected as the most ideal human implant product. For more than ten years, many scientific research departments, medical schools, hospitals, etc. in various countries and China have also done a lot of basic work and clinical research, and have recognized titanium as the most ideal human implant product in depth and breadth. In recent years, titanium has been used in Thousands of cases of artificial femoral heads, artificial wrist joints, knee joints, artificially implanted teeth, skull repairs, cardiac pacemakers, etc. made of materials have been recorded. After years of scientific research, tracking, and comparison, titanium is the most popular among the reports so far. The most ideal product for human implants. The design of orthopedic devices needs to conform to the complex shapes of bones and joints, so the processing of these parts is also complex. These devices, machined from titanium rods, require significant amounts of material to be removed, making the process expensive due to the low machinability index of many materials. Therefore, some parts are cast to approximate the shape of the part, which often requires complex and expensive fixtures. titanium pipe / Grade 16 Ti-0.5Pd Titanium Tube / Gr3 Pure Titanium Tube

Titanium 6AL-4V ELI is a standard product used to make hip joints, bone screws, knee joints, plate-shaped bones or organs, dentures and surgical equipment. However, cobalt-chromium alloys will become more commonly used due to their strength, finer grain size, and cleaner nature than titanium. The cutting forces required to machine titanium alloys are only slightly greater than those required to machine steel. However, the metallurgical properties of titanium alloys make them more difficult to machine than steels of appropriate hardness. Titanium has a titanium work hardening property that eliminates solid metal (curling) in front of the cutting tool. This helps to increase the shear angle during machining, thus forming thin chips that contact the cutting tool surface over a reasonably small area. Because of this work hardening property, the feed should not be interrupted during the moving contact between the tool and the workpiece. The large supporting force generated during machining, combined with the friction generated by the chips in the contact area, results in a significant increase in heat in the tool area. The heat generated by cutting titanium does not dissipate quickly because it is a poor conductor. Therefore, most of the heat is concentrated on the cutting edge and tool surface. The large bearing force and heat form craters near the cutting edge, causing the tool to be damaged quickly. To make matters worse, titanium alloys have a strong tendency to fuse with the products in the tool to form an alloy or to undergo chemical changes at the operating temperature of the tool. There is also a tendency that when chips adhere to the cutting edge of the tool, the surface of the tool will be damaged. damage. These difficulties are compounded when the tools begin to break, so tools used for machining titanium and its alloys should be carefully supervised to ensure that the edges are sharp and replaced before dulling. The experience of processing titanium and titanium alloys is that if you see any changes during the processing, you should change the tool immediately, because the change means that the tool will become dull. Another reason to keep your tools sharp is that titanium can cause a fire when cutting with broken or broken tools. When burned, the metal generates oxygen, so the fire ignites spontaneously. Therefore, many workshops that process titanium do not report fires. They equip machine tools with extinguishing systems.

Titanium has a moderately low modulus of elasticity and is more elastic than steel, so it will tend to resist cutting tools when machined unless it is to be cut firmly or used as a proper support. Slender parts tend to deflect under tool pressure, leading to problems with tool chatter, tool friction and work errors. Through processing experience, it is believed that the rigidity of the entire tool system is very important, and sharp, accurate-shaped tools must be used. As a result of these pressures, new technologies have been introduced to help shops manufacturing medical parts cope with competition. Machining performance produces these complex parts with very high precision. Many innovations in EDM have enabled the production of high-quality parts faster and eliminated many older machining technologies. problems inherent in it.

As a new product, titanium has only been developed and used in China's pharmaceutical industry, medical equipment, human implants and other fields for nearly two decades. However, it has achieved great success and achieved significant social and economic benefits, shortening the gap between China and international advanced countries. The use of titanium equipment in the production of many products not only solves the equipment corrosion problem that seriously plagues the company's production and development, but also greatly improves the quality of drugs.

Titanium tube has good weldability

Titanium tubes have good weldability. The welding performance of titanium materials depends on factors such as its chemical composition, grain size, and heat treatment state. Under the correct welding conditions, titanium tubes can be welded to other materials, including steel, stainless steel, and other titanium alloys.

Common titanium pipe welding methods include inert gas-shielded (TIG welding) and arc welding. These welding methods can ensure that the atmosphere in the welding area is protected from oxidation and pollution, thereby obtaining good weld quality. Gr12 Ti-0.3Mo-0.8Ni Titanium Pipe / Grade 23 Ti-6Al-4V ELI Titanium Pipe / Grade 9 Ti3Al2.5V Titanium Tube

Some key factors need to be paid attention to when welding titanium pipes, such as appropriate welding parameters, suitable welding materials, adequate argon gas protection, and temperature control during welding. In addition, due to the low thermal conductivity of titanium materials, attention needs to be paid to the heating and cooling control of the welding area during the welding process to avoid problems such as cracks and stress concentration.

In general, titanium pipes have good weldability and can be reliably welded to other materials through appropriate welding methods and process control to meet the needs of different application fields.

What are the forging methods of titanium metal materials?

Forging is a forming processing method that applies external force to titanium metal blanks (excluding plates) to cause plastic deformation, change size, and shape and improve properties, and is used to manufacture mechanical parts, workpieces, tools, or blanks. In addition, depending on the movement of the slider and the vertical and horizontal movement of the slider (for forging of slender parts, lubrication and cooling, and forging of parts for high-speed production), the compensation device can be used to increase movement in other directions. The above methods are different, and the required forging force, process, material utilization, output, dimensional tolerance, and lubrication and cooling methods are different. These factors also affect the level of automation. According to the movement mode of the blank, forging can be divided into free forging, upsetting, extrusion, die forging, closed die forging, and closed upsetting.

Since there is no flash in closed die forging and closed upsetting, the material utilization rate is high. It is possible to complete the finishing of complex forgings in one or several processes. Since there is no flash, the stress-bearing area of the forging is reduced and the required load is also reduced. However, care should be taken not to completely restrict the blank. To this end, it is necessary to strictly control the volume of the blank, control the relative position of the forging die measure the forgings, and strive to reduce the wear of the forging die. According to the movement mode of the forging die, forging can be divided into oscillating rolling, oscillating forging, roll forging, cross wedge rolling, ring rolling, and cross rolling. Oscillating rolling, oscillating forging, and rolling rings can also be processed by precision forging. In order to improve material utilization, roll forging and cross-rolling can be used as front-end processing of slender materials. Rotary forging, like open forging, is also locally formed. Its advantage is that it can be formed with a small forging force compared to the size of the forging. In this forging method including open forging, the material expands from the vicinity of the die surface to the free surface during processing, so it is difficult to achieve accuracy. Therefore, by using a computer to control the movement direction of the forging die and the rotary forging process, a lower speed can be used Forging force can produce products with complex shapes and high precision, such as forgings such as steam turbine blades with many varieties and large sizes. In order to obtain high accuracy, care should be taken to prevent overloading at the bottom dead center and control the speed and mold position. Because these will have an impact on forging tolerances, shape accuracy and forging die life. titanium forging / Titanium Threaded Forged Fitting / Gr3 Pure Titanium Plate

In addition, in order to maintain accuracy, attention should also be paid to adjusting the clearance and stiffness of the slider guide rail, adjusting the bottom dead center and using auxiliary transmission devices. The materials used for titanium forging are mainly pure titanium and titanium alloys of various compositions. The original states of titanium materials include bar stock, ingots, metal powder and liquid metal. The ratio of the cross-sectional area of the metal before deformation to the cross-sectional area after deformation is called the forging ratio. The correct selection of forging ratio, reasonable heating temperature and holding time, reasonable initial and final forging temperatures, reasonable deformation amount and deformation speed have a great relationship with improving product quality and reducing costs. Generally, small and medium-sized forgings use round or square bars as blanks. The grain structure and mechanical properties of the bar are uniform and good, the shape and size are accurate, and the surface quality is good, making it easy to organize mass production. As long as the heating temperature and deformation conditions are reasonably controlled, forgings with excellent performance can be forged without large forging deformation.