Characteristics of titanium alloy materials such as titanium rods and titanium alloy rods and types of heat treatment processes for rods

Titanium is very stable in the air at room temperature. When heated to 400-550 °C, a firm oxide film is formed on the surface, which plays a protective role to prevent further oxidation. Titanium has a strong ability to absorb oxygen, nitrogen, and hydrogen. These gases are impurities that are very harmful to metal titanium, and even a small content (0.01% to 0.005%) can seriously affect its mechanical properties. Among the titanium compounds, titanium dioxide (TiO2) has practical value. TiO2 is inert to the human body, non-toxic, and has a series of excellent optical properties. TiO2 is opaque, with high gloss and whiteness, high refractive index and scattering power, strong covering power, and good dispersibility. The pigment made is a white powder, commonly known as titanium dioxide, which is widely used. The appearance of the machined titanium round rod is very similar to that of steel, with a density of 4.51 g/cm3, which is less than 60% of that of steel, and is a metal element with low density in refractory metals. The mechanical properties of titanium, commonly known as mechanical properties, are closely related to purity. High-purity titanium has excellent machinability, good elongation, and area shrinkage, but low strength and is not suitable for structural materials. Industrial pure titanium contains an appropriate amount of impurities, has high strength and plasticity, and is suitable for making structural materials.

Titanium alloys are divided into low-strength and high-plasticity, medium-strength, and high-strength, ranging from 200 (low-strength) to 1300 (high-strength) MPa, but in general, titanium alloys can be regarded as high-strength alloys. They are stronger than aluminum alloys, which are considered medium-strength, and can completely replace certain types of steel in strength. Some titanium alloys can still maintain good strength at 600°C compared to aluminum alloys whose strength decreases rapidly at temperatures above 150°C. Dense metal titanium is highly valued by the aviation industry due to its lightweight, higher strength than aluminum alloys, and its ability to maintain higher strength than aluminum at high temperatures. Considering that the density of titanium is 57% of that of steel, its specific strength (strength/weight ratio or strength/density ratio) is high, and its anti-corrosion, anti-oxidation, and anti-fatigue capabilities are all strong, and 3/4 of titanium alloys are used as 1/4 of the structural materials represented by aviation structural alloys are mainly used as corrosion-resistant alloys. Titanium alloy has high strength and low density, good mechanical properties, good toughness, and corrosion resistance. In addition, the process performance of titanium alloy is poor, cutting is difficult, and it is very easy to absorb impurities such as hydrogen, oxygen, nitrogen, and carbon during hot processing. There is also poor wear resistance and a complex production process. The industrial production of titanium started in 1948. The need for the development of the aviation industry makes the titanium industry develop at an average annual growth rate of about 8%. At present, the annual output of titanium alloy processing materials in the world has reached more than 40,000 tons, and there are nearly 30 kinds of titanium alloy grades. The widely used titanium alloys are Ti-6Al-4V(TC4)'Ti-5Al-2.5Sn(TA7) and industrial pure titanium (TA1, TA2, and TA3).

There are three heat treatment processes for astm b348 titanium rod and titanium alloy rods:

1. Solution treatment and aging:

The purpose is to increase its strength, alpha titanium alloys and stable beta titanium alloys cannot be strengthened by heat treatment, and are only annealed in production. α+β titanium alloys and metastable β titanium alloys containing a small amount of α phase can be further strengthened by solution treatment and aging.

2. Stress relief annealing:

The purpose is to eliminate or reduce the residual stress generated during processing. Prevent chemical attacks and reduce deformation in some corrosive environments.

3. Complete annealing:

The purpose is to obtain good toughness, improve processing properties, facilitate reprocessing and improve dimensional and organizational stability.