The Difference Between Pure Titanium Plate and Titanium Alloy Plate

Many people will encounter the same problem when choosing titanium materials, that is, they are all titanium. What is the difference between pure titanium plates and titanium alloy plates? From the appearance alone, whether it is a sandblasted surface or an alkaline acid washed surface or a polished surface, most people cannot tell the difference. If you want to make a real distinction, you need a deeper analysis. Here's a brief explanation of the difference:

1. Analysis of chemical composition

We can first cut a part for chemical composition analysis through authoritative testing institutions. The impurity element content of commercial pure titanium does not exceed 0.1%, and the titanium alloy plate will have obvious differences according to the alloy ratio.

2. Hardness analysis

The hardness of pure titanium plate is 1/2 times that of ordinary steel plate. The hardness of industrial pure titanium is usually less than 120-290 Brinell hardness, the higher the purity, the closer the Brinell hardness is to 120 Brinell. The hardness of the highest purity grade of industrial pure titanium is usually less than 120 (Brinell du), and the hardness of other industrial pure titanium is 200--295 (Brinell). The hardness of pure titanium castings is 200-220 (Brinell). The hardness value of titanium alloy in the annealed state is 32-38 (Rockwell, C calibration), which is equivalent to 298-349 Brinell hardness. The as-cast and titanium Ti-6AL-4V had a hardness of 320 (Brinell) and the low interstitial impurity Ti-6AL-4V casting had a hardness of 310 (Brinell).

The hardness of the titanium alloy plate is basically around 250~350HV, and the alloy elements of the ta2 titanium alloy plate can be divided into three categories according to their influence on the phase transformation temperature:

1. The elements that stabilize the α phase and increase the phase transition temperature are α stable elements, such as aluminum, carbon, oxygen and nitrogen. Among them, aluminum is the main alloying element of titanium alloy, which has obvious effects on improving the normal and high temperature strength of the alloy, reducing the specific gravity and increasing the elastic modulus.

2. The elements that stabilize the β phase and reduce the phase transition temperature are β stable elements, which can be divided into two types: isomorphous and eutectoid. Products using titanium alloys, the former include molybdenum, niobium, vanadium, etc.; the latter include chromium, manganese, copper, iron, silicon, etc.

3. The elements that have little effect on the phase transition temperature are neutral elements, such as zirconium and tin.

3. With the help of professional equipment

Now spectrometers or X-ray fluorescence spectrometers and thermoelectric comparators can also quickly distinguish pure titanium plates from titanium alloy plates.

All in all, since pure titanium plates and titanium alloy plates have very good heat resistance, toughness, plasticity, strength, weldability, formability, corrosion resistance and biocompatibility, the current medical titanium materials such as artificial The plate materials implanted in joints, dental implants, bone fixation devices, etc. are generally mainly pure titanium plates and titanium alloy plates, among which ta4 pure titanium plate is the most common, tc4 is the most common titanium alloy plate, of which ti-6al -4v belongs to the main composition of tc4 titanium alloy plate. In the actual medical industrial production, there is still the risk of doping pure titanium plate and titanium alloy plate, which directly adversely affects the later surface treatment process and machining process. Since there is no significant difference between pure titanium plate and titanium alloy plate in terms of outer surface, density and other properties, after sampling and calcination, pure titanium plate and titanium alloy plate can be distinguished by observing the color of the oxide film of the sample with the naked eye. However, using this method to distinguish is generally laborious and slow, with poor reliability, and requires relatively high professional skills. Instruments can also be used to distinguish pure titanium and titanium alloys, and spectrometers/thermoelectric comparators/x-ray fluorescence spectrometers can also be used to distinguish pure titanium plates and titanium alloy plates, but most of these instruments are expensive to purchase and occupy space. Large and inconvenient to carry and move.