Titanium metal is a rare metal element, and there is a commonly used processing technology called "burning titanium". This process can eliminate surface impurities and release stress without affecting the composition of titanium alloy, so that a stable oxide film is formed on its surface, thereby improving its oxidation resistance, mechanical properties, and corrosion resistance, and can form a variety of colors.
The color change of burning titanium starts from black, to orange after heating, and then gradually changes to blue under the action of heat. After the flame reaches its maximum, the color gradually darkens and stays in a state similar to dark gray until the flame gradually goes out, becoming a very special color.
The color change order of burning titanium is: black-orange-blue-purple-gray-dark brown-dark gray, and finally goes out.
The color contrast of burned titanium is very sharp. The color becomes darker and even dark brown. The overall look is a process of color transition. The change from black to dark gray, especially the change from orange to purple, makes this color change effect more comparable. The burned titanium metal presents a copper-like color, with a velvety appearance, smooth and upright, which is very worth collecting.
Titanium oxidizes at high temperatures and is covered with a very thin naturally generated oxide film on the surface. Different temperatures form oxide films of different thicknesses. After the oxide film is refracted by light and absorbs light of different wavelengths, it presents a variety of colors. This is physical coloring, so it can be used with complete confidence.
Process steps
The process steps of burning titanium alloy generally include the following aspects:
1. Pretreatment: Clean the surface of the titanium alloy and remove surface impurities and oxides.
2. Preheating: Preheat the titanium alloy to increase its surface temperature.
3. Oxidation: React the surface of the titanium alloy with oxygen in the air to form TiO2 oxide. The temperature and oxidation rate need to be controlled during the reaction to ensure that the generated oxide is uniform and dense.
4. Reduction: At high temperature, the oxidized titanium alloy surface is reduced to remove oxides and release stress, generate α-Ti phase structure, and form a dense and hard surface.
Firing preparation
1. Spray gun or gas stove.
2. Anti-scalding gloves.
3. Long-handled clamps or pliers.
4. Iron racks are used to place the fired cups for natural cooling.
First of all, we need to wash the cups clean and wipe off the water during the firing process.
You need to know the approximate process of titanium discoloration at different temperatures. As the temperature rises, the titanium cup is initially silver-white, then light yellow, golden yellow, blue, purple, gray-red, and gray. After understanding this, you can conceive in your mind what kind of cup you want to burn.
When you see the cup burning red, you must control the time well. Don't burn it red for too long, otherwise it will burn white, and you won't get the color you want. Generally, it may take ten seconds to burn red. You need to leave the fire and wait for it to cool down. You can see the coloring. If blue comes out, this is the time required for burning blue. You will have a rough idea in your mind. The time slightly shorter than blue is purple or red, and the gold time above is even shorter. Don't be afraid of spending time and paying attention to the coloring at any time.
You may not be very skilled at burning the first one. Don't put cold water on the burned titanium cup. Wait for it to cool down naturally and then wash it.
Precautions for burning titanium
1. The temperature and oxidation-reduction rate need to be fully controlled during the burning of titanium alloy to ensure the process effect.
2. Pay attention to safety during the process to avoid the generation of dangerous gases and chemicals.
3. After burning titanium alloy, the surface needs to be cleaned and coated to protect the oxide film on the surface and extend its service life.
