1、 The concepts of annealed and hot-rolled states

Titanium alloy is a high-strength, low-density, corrosion-resistant metal material widely used in aviation, aerospace, metallurgy, chemical and other fields. Titanium alloys can be processed in various ways to obtain different material states, among which annealed and hot-rolled states are common.

Annealing state refers to the processing state where titanium alloy is heated to a certain temperature and then slowly cooled to room temperature. During this process, the grain size of titanium alloy increases, internal stress is released, material hardness decreases, and it exhibits certain plasticity and toughness.

Hot rolled state refers to the processing state in which titanium alloy is heated to high temperature and then pressed and deformed on a roller conveyor. During this process, titanium alloy undergoes strong plastic deformation, resulting in finer grain size, increased hardness, and improved mechanical properties and strength.

2、 Differences in Cold Deformation Degree

During the preparation process of titanium alloys, cold deformation machining is often required to improve material properties. The difference between annealed and hot-rolled states mainly lies in their degree of cold deformation.

Annealed titanium alloys typically undergo minor deformations to maintain their plasticity and toughness. The hot-rolled titanium alloy undergoes significant deformation to improve its hardness and strength.

3、 Differences in grain size and hardness

The grain size of titanium alloys is an important parameter that affects material properties. The smaller the grain size, the better the corrosion resistance, strength, and plasticity of the material.

The grain size of annealed titanium alloys is generally between 1-10 microns. Because during the annealing process, the grains regrow and the material hardness decreases. On the contrary, the grain size of hot-rolled titanium alloys is small, usually between 0.1-1 microns, and the material hardness and strength are relatively high.

4、 Differences in mechanical properties and applications

The mechanical properties of titanium alloys are also directly affected by the material state. Annealed titanium alloys have relatively low strength and hardness, but have good plasticity and toughness, making them suitable for manufacturing high-strength and high toughness parts. Hot rolled titanium alloys have higher strength and hardness, making them suitable for manufacturing high-strength and high stiffness parts.