Titanium alloy plate is an alloy composed of titanium added with other elements. Titanium has two kinds of crystals: close-packed hexagonal α titanium below 882℃, and body-centered cubic β titanium above 882℃. Technical requirements: 1: The chemical composition of titanium and titanium alloy plates should meet the requirements of GB/T 3620.1, and the allowable deviation of the chemical composition should meet the requirements of GB/T 3620.2 when the buyer re-inspects. 2: The allowable deviation of the thickness of the plate should meet the regulations. 3: The allowable deviation of the width and length of the plate should meet the regulations. 4: The corners of the plate should be cut at right angles as much as possible. When cutting, the length and width of the plate should not exceed the allowable deviation. .
Titanium alloys are alloys based on titanium added with other elements. Titanium has two kinds of crystals: close-packed hexagonal α titanium below 882℃, and body-centered cubic β titanium above 882℃. Alloying elements can be divided into three categories according to their influence on the phase transition temperature:
① The elements that stabilize the α phase and increase the phase transition temperature are α stabilizing elements, such as aluminum, carbon, oxygen, and nitrogen. Among them, aluminum is the main alloy element of titanium alloy, which has obvious effects on improving the alloy's normal temperature and high temperature strength, reducing the specific gravity, and increasing the elastic modulus.
②The element that stabilizes the β phase and reduces the phase transition temperature is the β-stabilizing element, which can be divided into two types: isomorphic and eutectoid. Products using titanium alloys. The former includes molybdenum, niobium, vanadium, etc.; the latter includes chromium, manganese, copper, iron, and silicon.
③ The elements that have little effect on the phase transition temperature are neutral elements, such as zirconium and tin. Oxygen, nitrogen, carbon and hydrogen are the main impurities in titanium alloys. Oxygen and nitrogen have greater solubility in the α phase, which has a significant strengthening effect on the titanium alloy, but it reduces the plasticity. Titanium alloy plates usually stipulate that the content of oxygen and nitrogen in titanium should be 0.15-0.2% and 0.04-0.05%, respectively. The solubility of hydrogen in the alpha phase is very small. Too much hydrogen dissolved in the titanium alloy will produce hydrides, which will make the alloy brittle. Generally, the hydrogen content in titanium alloys is controlled below 0.015%. The dissolution of hydrogen in titanium is reversible and can be removed by vacuum annealing.
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