2020年10月26日星期一

Forming process of titanium rod and titanium alloy rod under hot extrusion

Due to the tendency of titanium alloy materials to fill the grinding wheel, it brings difficulties to the grinding of titanium alloy rods and TC4 titanium alloy. During grinding, a higher temperature rise is generated at the interface between the metal and the grinding wheel, causing the grinding surface to be produced. Higher residual stress, at the same time, the surface finish is not ideal.
The following methods can basically solve these difficulties:
(1) Choose a suitable grinding wheel, such as a silicon carbide grinding wheel, the size of the grit is medium (60~80), the hardness is a medium (J~M), the surface speed is 700~1200m/min, alumina (aluminum oxide powder or corundum) The grinding wheel should be used at a lower speed, such as 550~600min. It also requires medium granularity.
(2) Use lower grinding wheel speed and feed speed; due to low grinding wheel speed, less sparks are generated.
(3) Cool with buffer or cutting fluid coolant, use ceramic bond and chlorinated or sulfided cutting oil to obtain good results. No matter what type of coolant is used, it must be well filtered to eliminate the "fishtail"-like stains caused by the recycling of titanium particles.
(4) Titanium sparks may catch fire when encountering oil mist, but immersing the workpiece with oil can reduce this danger. The rust-proof ammonium nitrite aqueous solution can completely eliminate the risk of fire.
But even the best grinding conditions will reduce the fatigue performance of the workpiece

2020年10月23日星期五

Control and treatment of surface quality of titanium forged parts

Biomedical materials, also known as biomaterials, are materials with special properties that are used for artificial organs, surgical repair, physical therapy rehabilitation, diagnosis and treatment of diseases, and to enhance or restore human tissue functions without adversely affecting the human body. With the increase of the aging society and the sharp increase of accidental injuries, the number of people who suffer from trauma is about tens of millions worldwide each year, and about 3 million in mainland China. A considerable number of bone trauma patients require early treatment or late treatment to varying degrees. Repair, bone tissue repair materials have a huge market demand. According to statistics from the Ministry of Science and Technology, my country's biomaterials and products have maintained a relatively high growth rate for more than ten years, but my country's biomaterials and products account for a relatively small market share in the world and have huge room for development.
Medical metal materials currently used in clinical practice mainly include stainless steel, cobalt alloys and iron alloys. Titanium and titanium alloys have an elastic modulus that basically matches the hard tissue of the human body, have good corrosion resistance and high fatigue resistance. The advantages of non-toxicity have received widespread attention. Today, titanium alloy artificial joints, dental implants, endovascular stents, heart valves and other medical device products have come out, which is of great significance to the development of medicine.

2020年10月21日星期三

Advantages, Disadvantages and Applications of Titanium Alloy Fasteners

①High specific strength. Titanium alloy has a low density and moderate strength, which can meet the strength requirements of bones, joints, surgical instruments and other medical devices. At the same time, titanium medical devices are relatively lightweight, which greatly reduces the load on the human body and provides high user comfort.
②Good mechanical compatibility. The elastic modulus of titanium and titanium alloys is far closer to human bones than stainless steel, cobalt-chromium alloys, etc. The elastic modulus can be reduced to 40-100 GPa, which can reduce the stress shielding effect of human bones on implants, and has a good match with human bones.
③Good corrosion resistance. There is a thin oxide film on the surface of the titanium alloy, which has good chemical stability and is corroded by antibody liquid, which is suitable for the use of various parts of the body.
④Biocompatibility, good health, non-toxic, non-allergenic.
⑤ Good processing and shapeability, suitable for making plates, rods, wires, nets, tubes, special-shaped parts, etc.
In addition, titanium alloy has low X-ray absorption rate, good X-ray visibility, and most of them are insensitive to magnetic fields, are not affected by electromagnetic fields and thunderstorms, and will not affect patients' X-ray and MRI examination; Titanium nickel alloy also has a unique shape memory function and superelasticity. Based on the above characteristics, titanium and titanium alloys have become biometal materials with a wide range of applications.

2020年10月18日星期日

Structural changes of titanium rods and titanium alloy rods during hot extrusion

Titanium plates made of titanium and titanium alloys. Titanium processed products such as titanium rods, titanium tubes, and titanium wires have excellent performance, high specific strength, and corrosion resistance. They are important metals in aerospace, offshore oil industry, medical equipment and other fields. However, due to the high cost of titanium alloy manufacturing, In order to reduce its cost, the competitiveness of titanium alloys in the entire metal material market is increased at a lower price. It is generally believed that titanium has superior properties that other materials cannot match, but the price of titanium often discourages consumers (especially car manufacturers). The emergence of high-quality and low-cost titanium alloys will certainly help expand the application of titanium and titanium alloys.
Judging from the application status at home and abroad and the development of titanium processing technology, the plastic processing technology of titanium and titanium alloys will develop in the following directions in the future:
(1) High performance, that is, the development of alloys with higher service temperature, higher specific strength, higher specific modulus, better corrosion resistance and wear resistance.
(2) Multifunctionalization, that is, the development of titanium alloys with various special functions and uses, such as high damping, low expansion, constant resistance, high resistance, resistance to electrolytic passivation and hydrogen storage, shape memory, superconductivity, and low modulus biology Titanium alloys such as medical use to further expand the application of titanium and titanium alloys.
(3) Deepen the research of traditional alloys, improve the practical performance of existing alloys through equipment and process improvements, and expand the scope of use of traditional alloys.
(4) Adopt advanced processing technology, large-scale and continuous processing equipment, and develop continuous processing technology, direct rolling technology, cold forming technology and near net forming technology to improve the production efficiency, yield and product performance of titanium alloys .
(5) Low cost, develop alloys that do not contain or contain precious metal elements, and add cheap elements such as iron, oxygen, and nitrogen, and develop titanium alloys that are easy to process, easy to cut, alloy elements, and master alloys. Develop titanium alloys that maximize the use of waste materials and increase the recycling rate of waste titanium. This is particularly important for reducing the cost of civilian titanium alloys.

2020年10月13日星期二

titanium seamless pipes rolling method and precautions

With the continuous expansion of the application field of titanium pipes, the dosage is also rising. Our titanium pipes have been applied in construction, in order to make the construction more scientific to provide users with high-performance titanium pipes.
The hard work always pays off. After customers use the titanium tubes we produce and process, they have a very high evaluation, established a long-term cooperative relationship, and continue to introduce customers to our company.
The research on refractory materials for casting molds has always been linked to the crucible materials for smelting titanium tubes and titanium alloy tubes. Based on dynamics, the crucible material has to be in contact with the titanium liquid for a long time during smelting, and the titanium liquid and The contact time of the holding material is much shorter, so the usable crucible material can be used as the casting material of the titanium alloy tube.
The materials that have been studied include carbides, nitrides, borides, sulfides, oxides, rare earth oxides, fluorides, oxyfluorides, sulfur oxides, and refractory metals such as W and Mo. Only a few materials have high chemical stability to titanium liquid, including ThO2, some rare earth oxides, TaB2, Npc, some rare earth sulfides and some rare earth oxyfluorides.

2020年10月11日星期日

Smelting and casting process of titanium and 6al 4v titanium plates

Titanium is stable in the air at room temperature; because titanium has a low density and high strength, the density is only half that of steel, but the strength is similar to steel, high-temperature resistance, low-temperature resistance, and corrosion resistance. The strength of titanium alloy is higher than steel. Titanium is known as "space metal" and can maintain high strength and mechanical properties in a wide temperature range of -253°C to 500°C. Since the 1950s, its proportion in aerospace has become larger and larger, and titanium alloys have become necessary materials for rocket engine shells, artificial satellites, and spacecraft.
Titanium maintains its own color tone for life at room temperature, and its unique silver-grey tone is highly polished and mercerized. Matte has a very good performance. It is the most suitable jewelry metal except platinum and gold. It is often used in modern foreign jewelry designs. However, due to the high processing technology requirements of titanium, it is difficult to cast it with ordinary equipment, and it is difficult to weld it with ordinary tools, so it is difficult to form a production scale. Titanium is light but extremely strong. It is an internationally popular jewelry material. In terms of design, its minimalist and clean-cut, high design and low-key avant-garde style are highly respected by young white-collar workers.
A titanium rod is a special metal. It has a small density and lightweight but has high specific strength and strong corrosion resistance. It will not turn black like silver and will maintain its silvery-white tone for life at room temperature. Titanium has a high melting point and is often used in aerospace. Military precision parts. In terms of chemical reaction, the strong corrosive "Aqua regia" can swallow silver and gold, and even erode the so-called "stainless" stainless steel. However, "Aqua regia" has no alternative to titanium. It has been immersed in "Aqua regia" for several years. Titanium is still shining! Titanium is also added to stainless steel to resist acid and alkali.
Titanium plate has a unique purpose in medical doctors. When titanium metal comes in contact with substances, there will be no chemical reaction. In other words, because of the high corrosion resistance and stability of titanium, it will not affect its essence after long-term contact with people, so it will not cause human allergies. It is the only one that has no effect on human autonomic nerves and taste. metal. Titanium is also called "biophilic metal". In the bone damage, fix it with a titanium splint and a titanium bone nail. After a few months, the bone will grow on the titanium splint and the thread of the titanium bone nail, and the new muscle will be wrapped in the titanium splint. "Titanium bone" is just like real bone, and even titanium artificial bone can be used instead of bone to treat fractures.

2020年10月9日星期五

How does the titanium plate modify the surface of the titanium plate and improve the toughness?

Titanium is an ideal structural material. The density of titanium is only 4.5g/m3, which is 43% lighter than steel, but its strength is twice as high as iron and almost 5 times higher than pure aluminum. It has low density and high strength performance. The combination of this high strength and low density makes titanium occupy an extremely important position in technology. At the same time, the corrosion resistance of titanium is close to or higher than that of stainless steel, so it has been widely used in petroleum, chemical industry, pesticides, dyes, papermaking, light industry, aviation, space development, ocean engineering, etc.
1. Before heat treatment, oil stains, paints, fingerprints and other foreign objects (rag wire, fine iron filings, etc.) on the surface of titanium parts should be cleaned, otherwise, it will easily cause pollution during heating and affect the performance of the parts. In particular, the hazards of fingerprints should be pointed out. The high-temperature test shows that when the sample is stressed and is in contact with pure NaCl, the sample will crack, which is the result of hot salt stress corrosion. In 1955, it was discovered abroad that there were surface cracks in Ti-6Al-4V alloy samples after creep test at 371℃. Research and analysis have determined that the appearance of these cracks is usually related to fingerprints. Since fingerprints are harmful to the workpiece, you should avoid direct contact between your fingers and the workpiece during operation, and you must wear clean white gloves when taking parts at room temperature. In addition, titanium alloys must not be processed in the same furnace as aluminum, copper, etc., let alone processed in the same tray.
2. During heat treatment, the titanium parts are heated to a higher temperature and kept at the high temperature for a certain period of time. As the heated material is soft and easily deformed, the position of the parts on the tray or bracket is very important. If the tray itself is not flat, the parts will deform. If heat treatment fixtures are used to improve the deformation of parts, the expansion of parts and fixtures after heating should be taken into account at this time.

The production of titanium rods requires a heat treatment process

The production of titanium rods usually requires a heat treatment process to improve the material properties of the titanium alloy, remove i...