Difference between Gr5 and Gr5ELI of titanium alloy

Gr5 Titanium Alloy

　　Gr5 titanium alloy is an α-β type titanium alloy developed in 1954 by the United States, containing 6% α-stable elements and 4% β-stable elements V. Gr5 titanium alloy has a nominal composition of 7.0 aluminum equivalent, 2.9 molybdenum equivalent, and 10%-15% β-phase in the annealed state. The favorable effect of V on the plasticity of titanium alloys is due to the fact that it does not increase the ratio of the c/a axis of the α-state lattice, as most alloying elements do, but rather reduces it, thus increasing the formation of the α-phase and avoiding alloy embrittlement during prolonged use.

　　The main characteristics of Gr5 titanium alloy are excellent overall performance and good process performance. Gr5 titanium alloy has medium room temperature strength and high temperature strength, good creep resistance and thermal stability, high fatigue resistance and crack extension resistance in seawater, as well as satisfactory fracture toughness and resistance to hot salt stress corrosion, the sensitivity to hydrogen is also smaller than TC2, TC1 alloy, suitable for the manufacture of - Gr5 titanium alloy also has excellent process plasticity and superplasticity, suitable for forming by various pressure processing methods, and various ways of welding and mechanical processing.

　　The main semi-finished products of Gr5 titanium alloy are in the form of bars, forgings, sheets, thick plates, profiles and wires, etc. They are also used for castings (ZTC4).

　　Gr5ELI Titanium Alloy

　　Gr5ELI is a modified version of TC4, the main difference being the different Al content and the lower content of interstitial elements Fe, N, H and O.

　　Gr5ELI titanium alloy is an ideal material for medical surgical implants because of its good biocompatibility, low modulus of elasticity, low density, good corrosion resistance, non-toxicity, high yield strength, long fatigue life, high plasticity at room temperature, and easy forming. Medical TC4ELI titanium alloy plate is mainly used for cranial repair, bone jointing, etc., which has higher requirements for its strength, fatigue life, plasticity, etc.

　　Titanium alloy is an alloy composed of titanium based on the addition of other elements. Titanium has two kinds of homogeneous heterocrystals: titanium is a homogeneous isomer with a melting point of 1668°C. It has a dense hexagonal lattice structure below 882°C, called α-titanium, and a body-centered cubic lattice structure above 882°C, called β-titanium. Using the above two structural characteristics of titanium, add the appropriate alloying elements, so that its phase change temperature and component content gradually change and get different titanium alloys (titanium alloys).

　　Gr5 ELI titanium alloy is based on Gr5 alloy, reducing the content of interstitial elements C, O, N and impurity elements Fe, the strength is reduced, but can significantly improve the tolerance toughness. Gr5 ELI has better plasticity, toughness, good welding performance and low temperature performance, widely used in cryogenic engineering, medical, naval and aircraft and other important fields.

　　Gr5 alloy can be used in general environment or high temperature environment, Gr5ELI alloy can be used in ultra-low temperature environment

　　Gr5 titanium alloy and TC4ELI titanium alloy similar grades are: T-6A-4V/Grade 5 (American grade), BT 6 (Russian grade), IMI 318 (British grade), TiAI6V4 (German grade).

　　Medical equipment manufacturing in the human body due to trauma, tumor caused by bone, joint injury, the use of titanium and titanium alloy manufacturing artificial joints, joint plates and screws, is now widely used in clinical. Also used in hip joints (including femoral head), knee joints, elbow joints, metacarpophalangeal joints, interphalangeal joints, mandibles, artificial vertebrae (spinal orthoses), cardiac pacemaker shells, artificial heart (heart-shaped valves), artificial dental implants, titanium-nickel orthodontic appliances and titanium mesh in skull shaping, etc.

　　Titanium and titanium alloys are gaining importance due to their high specific strength, biocompatibility and resistance to corrosion of body fluids.

　　Ti 6Al-4V ELI is a Ti 6Al-4V grade with a small tissue gap, which allows for maximum toughness and is suitable for seawater and low temperature environments. Ti 6Al-4V is a good material choice for medical implants.

　　The production process is: relaxation annealing at 900-120 degrees Fahrenheit for 1-4 hours, air cooling. For double annealing, the process for round bars and forgings is: solution annealing at a beta transition temperature of 50-100 degrees Fahrenheit, held for at least 1 hour and then air cooled, followed by reheating at 1300-1400 degrees Fahrenheit, held for at least 1 hour and then air cooled. Relaxation annealing is suitable after welding