Titanium exhibits three unique basic characteristics during titanium metal heating, which are of great significance for the processing and application of titanium metal.
First, compared with common metals such as copper, aluminum, iron, and nickel, titanium has a relatively low thermal conductivity. This means that under the same heating conditions, titanium metal transfers heat more slowly. More specifically, the thermal conductivity of titanium alloys will gradually decrease with increasing temperature. This characteristic makes it take longer to achieve the desired heating effect when heating titanium alloys using surface heating methods. Especially for large billets, due to their large volume, internal heat transfer is more difficult during heating, so the cross-sectional temperature difference will be relatively large, which increases the complexity of the titanium metal heating process and the requirements for heating equipment.
Secondly, titanium alloys react with gases such as oxygen and nitrogen at high temperatures to form a layer of oxide scale and an air absorption layer. This air absorption layer not only affects the appearance quality of titanium alloys, but more importantly, it deteriorates their processing performance. For example, the air absorption layer causes titanium alloys to generate more heat and friction during cutting, thereby increasing tool wear and metal loss. Therefore, during the titanium metal heating, intermediate machining is often required to remove this layer of absorption layer, which undoubtedly increases the production cost and processing difficulty.
Finally, when titanium metal is heated at high temperatures and in a reducing atmosphere, it absorbs a large amount of hydrogen. Hydrogen is an element that is harmful to the performance of titanium alloys. It will cause the strength and toughness of titanium alloys to decrease, and even produce defects such as cracks. Therefore, the atmospheric conditions must be strictly controlled during the titanium metal heating process to prevent the titanium alloy from absorbing excessive hydrogen. Once the hydrogen content in the titanium alloy exceeds the standard, additional treatment is required to remove hydrogen, which will also increase the production cost and processing cycle.
In summary, the three characteristics shown in the titanium metal heating process have an important impact on its processing and application. In order to obtain high-quality titanium alloy products, it is necessary to have a deep understanding of these characteristics and take corresponding measures to deal with them.
