Who knows what equipment and tools to weld hard alloys on knives and milling knives.

Answer:

The advantage of induction heating brazing is heated rapidly, solder short liquefaction process, and can in a variety of atmosphere (air, gas, vacuum, under can alleviate hard alloy overheating and oxidation, to improve welding quality. The shortcoming of this method is more complex equipment, one-time investment is larger, the second effect is the trend of the induced current in the table, when brazing big thick workpiece, uneven heating temperature, difficult to guarantee the quality of brazing, and the efficiency is low, so generally applies only to brazing structure simple (preferably axial slender shape) the small size of welding [2]. The process parameters of induction brazing are generally including the factors such as the gap of the drill, the speed of heating, the speed of cooling, the shape of the induction coil and the addition of the solder. These factors must have a suitable range of equipping, factors of fluctuations affect the quality of weld, especially in hard alloy is formed in a large welding stress.

Flame brazing is a method of welding the flame as a source of heat by using combustible gas (acetylene, propane, etc.) with oxygen or compressed air. Flame brazing equipment is simple and easy to operate, and it can be heated and welded according to the shape of the workpiece. The solder can be made of silk or flake copper and silver solder, including the most widely used of HL105 manganese bronze solder. It is commonly used to remove borax. Flame brazing is mainly suitable for small and medium size carbide cutting tools, mould and measuring tool of small batch production, for a large carbide tool, because the flame heating temperature and speed control, the heating will produce larger temperature gradient, easy to cause cracks, so generally do not adopt this method?

According to the difference of the protective atmosphere, it can be divided into reduced gas and inert gas furnace brazing. The reductive gas is usually H2 or CO, not only to avoid the oxidation of the workpiece during the heating process, but also to reduce the oxidation film on the surface of the workpiece, which can help to moisten the solder. Inert gas Ar, N2, and He, is commonly used in demand for gas purity is higher, generally in more than 99.99%, even after dehydration before gas charging (silica gel, sulfuric acid) DNA (titanium sponge) device. The workpiece is usually placed in a container and heated brazing in a flowing gas. The use of inert gas is higher than the safety of the reduced gas. Heating temperature, heat preservation time and cooling rate are the main process parameters. When heating temperature higher than 900 ℃, the hardness of cemented carbide are significantly reduced. The hardness of hard alloy can also be reduced when the insulation is too long. After welding, it should be cooled slowly to prevent cracking

Are important components of induction heating equipment, induction coil, ac power energy is passed through it to welding and heating, therefore, the structure of the induction coil is reasonable has a great influence for brazing quality and productivity. Induction coil, correct design and selection principles are: the appearance of induction coil shall be compatible with weldment, minimize the useless gap between itself and the induction coil, welding, had better not greater than 2 ~ 3 mm gap, in order to improve the efficiency of heating. In order to make the welding heating smooth, uniform, prevent welding Angle may cause local overheating, should the number of turns and the induced current of induction coil, reasonable selection of parameters such as alternating frequency.

Resistance brazing can be divided into direct heating and indirect heating. The direct heating method is to put the electrode on both sides of the joint, causing the current to pass through the contact resistance of the brazing surface and heat up to complete the welding process. Indirect heating method is put electrodes in joint on one side of the steel on the parent metal, current through the parent metal on one side of the brazing seam resistance heating (or by heating element) brazing. The indirect heating method can avoid the contact of the electrode with hard alloy, prevent the heat and loss of hard alloy and avoid the decrease and cracking of hardness. But with copper or silver based solder, commonly used have H68, HL105 solder, etc., including HL105 shear strength of solder is higher, for welding YT5 knives, shear strength can be up to 28.5 GPa, for YG8 can reach 29.7 GPa. It is commonly used to remove borax