Tungsten Boat
Introduction
Tungsten boat is also known as evaporated tungsten boat or coated tungsten boat which is formed by tungsten sheet through high-pressure. Nowadays, W-boat is widely used in vacuum coating industry and sintering furnace and annealing boat industry. It is also widely used in electronics industry, such as kinescope, mirror making, toys, household appliances, mobile phones, electrical enclosure. It has good characteristics for electrical conductivity, thermal conductivity, high temperature resistance, wear resistance, corrosion resistance. Wolfram boat, as an essential part for vacuum coating equipment, the selection of it determines the quality of the coating.
Stamping Tungsten Boat
Stamping type tungsten boat is formed by conventional or special stamping equipment to put pressure on wolfram plate to produce plastic deformation in stamping die. The main processing of stamping W-boat is hot stamping. Tungsten boats made by stamping can increase its rigidity, because the press generally do not have chips and the consumption tungsten plate is less and the low cost, therefore, the price of stamping wolfram boat will be relatively low.
Folding Tungsten Boat
Manufacturing process of the folding tungsten boat is more complicated. Through the repeated folding and forging on tungsten plate, and then both ends of a tungsten plate will be folded, forming the shape of the boat. Folding wolfram boat has a strong permeability. Compared to other types of W-boat, this type of W-boat has a series of complement: cover and its body.
Welding Tungsten Boat
Welding W-boat is also known as heating wolfram boat. Welding is connected directly to connecting position of the two metals together by the melting at high temperature. Heating and pressing five pieces of tungsten plates at a high temperature so that the connection can be melted together, cooling it after welding, forming the final shape of the boat. However, it would take long time to produce a welding W-boat, because that it can be made for one time. Welding of pure tungsten is generally divided into fusion welding and braze. The sizeof this type of wolfram boat is relatively large.
Riveting Tungsten Boat
A rivet is a permanent mechanical fastener. Before being installed, a rivet consists of a smooth cylindrical shaft with a head on one end. Generally, using wolfram clinch bolts to connect two tungsten plates. Thus, the strength of riveted joints of riveting W-boat is stable and reliable that can improve the tightness of tungsten boat. In other words, riveting W-boat is made by two wolfram plates which have the same thickness, make a hole in the joint, and then use the wolfram clinch bolts to connect them so that the two tungsten plates can fit together. On the other hand, it can to form a complex structure of the tungsten boat.
Evaporating Tungsten Boat
Evaporating tungsten boat is widely used as source for evaporation resistancethe and component of the boat is made of tungsten metal. And then connect both ends of the component by wire, and put a low melting point metal in the middle of the concave position. Under the electrify condition, the temperature of tungsten boat would rise to about 2000 degrees, so that the metal can evaporate into gas and deposited on the surface of the workpiece.
Sintering Tungsten Boat
Sintering tungsten boat is mainly used in the production of tungsten powder. Burning ammonium paratungstate into yellow tungsten oxide or blue tungsten oxide, and then make tungsten powder in hydrogen. During the manufacturing process, tungsten oxide should be placed in a tungsten boat and then put in the reduction furnace. After recycling the hydrogen, remove the tungsten boat.