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Before smelting, the chemical composition of all metal charges must meet the requirements, the appearance is clean, and there is no oil and sand. It should be preheated to 200-300°C before entering the furnace, and the new graphite crucible should be heated slowly to 900°C for roasting before use. Old crucibles should first be inspected for damage and then cleaned of slag and metal adhering to the crucible walls. Preheat to 500-600°C before loading. All tools in contact with zinc alloy must be cleaned, sprayed with paint, and fully dried before use. The melting process is simple and easy, and does not require special slag making and degassing treatment, nor does it need to use special covering agents. The melting speed is fast, the melting efficiency is high, and the energy consumption is small. In order to limit the introduction of harmful impurities, the purity of raw materials is required to be high. In addition, when preparing materials, the furnace materials should be separated from titanium alloys and copper alloys. The melting process should be stirred up and down to avoid specific gravity segregation. Melting should be rapid and should not be overheated.

1. Heating characteristics
   Due to the low thermal conductivity of titanium alloy, the heating time is quite long, and the temperature difference of the heating section of the large billet is large. Titanium rods will react with oxygen and nitrogen at high temperatures to form oxide scales and getter layers, greatly increasing metal loss. Heating in a high-temperature reducing atmosphere will absorb hydrogen and make the hydrogen exceed the standard.
2. Heating furnace
   There are two types of heating furnaces commonly used by titanium and titanium alloy manufacturers for forging: flame heating furnaces (heavy oil furnaces, natural gas furnaces) and electric heating furnaces (box-type resistance furnaces). The heavy oil furnace is characterized by fast heating, high production efficiency, and easy control of furnace temperature. The maximum temperature is 1300°C.
   Natural gas furnaces are divided into chamber furnaces, trolley furnaces and continuous furnaces. The fuel for gas stoves is mostly natural gas. The main advantages of the natural gas furnace: it is convenient and reliable to adjust the furnace temperature, the atmosphere in the furnace is easy to control, and the specific fuel consumption is less.
   Compared with the flame furnace, the electric furnace (only called resistance furnace) has the following characteristics: the temperature of furnace 1 is easy to control and adjust, the furnace temperature is uniform, the heating quality is high, the scale is small, the structure is simple, the floor area is small, the working conditions are good, and there is no pollution to the environment. Heating efficiency: low efficiency, heating elements must be replaced frequently.
   The structure of electric furnace is various, including box type, well type, straight-through electric furnace and so on. At present, box-type electric furnaces are generally used in China.