Mold plays an extremely important role in modern industry, and its quality directly determines the quality of products. Improving the service life and precision of molds and shortening the manufacturing cycle of molds are technical problems that many companies need to solve urgently. However, failure forms such as collapse, deformation, wear, and even breakage often occur during the use of molds.
Argon arc welding repair
Welding is performed by using the burning arc between the continuously fed welding wire and the workpiece as the heat source, and the gas shielded arc ejected from the torch nozzle. At present, argon arc welding is a commonly used method, which can be applied to most major metals, including carbon steel and alloy steel. Metal inert gas shielded welding is suitable for stainless steel, aluminum, magnesium, copper, titanium, zirconium and nickel alloys. Due to its low price, it is widely used in mold repair welding, but it has disadvantages such as large heat-affected area and large solder joints. Precision mold repair has been gradually replaced by laser welding.
Mold Patching Machine Repair
Mold repairing machine is a high-tech equipment for repairing mold surface wear and processing defects. The mold repairing machine strengthens the mold with long service life and good economic benefits. It can be applied to various iron-based alloys (carbon steel, alloy steel, cast iron), nickel-based alloys and other metal materials to strengthen and repair the surface of molds and workpieces, and greatly increase the service life.
1. The principle of mold repairing machine
It uses the principle of high-frequency electric spark discharge to repair the surface defects and wear of the metal mold by athermal surfacing welding on the workpiece. The main feature is that the heat-affected area is small, and the mold will not be deformed after repairing, no annealing, no stress concentration, and no Cracks appear to ensure the integrity of the mold; it can also be used to strengthen the surface of the mold workpiece to meet the wear resistance, heat resistance, corrosion resistance and other performance requirements of the mold.
2. Application scope
The mold repairing machine can be used in machinery, automobile, light industry, household appliances, petroleum, chemical industry and electric power industries, for the repair and surface strengthening treatment of hot extrusion molds, warm extrusion film tools, hot forging molds, rolls and key parts .
For example, the ESD-05 electric spark surfacing repair machine can be used to repair wear, bruises, and scratches on injection molds, and to repair rust, peeling, and damage of die-casting molds such as zinc-aluminum die-casting molds. The power of the machine is 900W, the input voltage is AC220V, the frequency is 50~500Hz, the voltage range is 20~100V, and the output percentage is 10%~100%.
Brush Plating Repair
The brush plating technology adopts a special DC power supply equipment. The positive pole of the power supply is connected to the plating pen as the anode during brush plating; the negative pole of the power supply is connected to the workpiece as the cathode during brush plating. The plating pen usually uses high-purity fine graphite block as Anode material, graphite block wrapped in cotton and wear-resistant polyester cotton sleeve.
When working, the power supply assembly is adjusted to a suitable voltage, and the plating pen soaked in the plating solution is in contact with the surface of the repaired workpiece at a certain relative speed, and the metal ions in the plating solution diffuse to the workpiece under the action of the electric field force On the surface, electrons obtained on the surface are reduced to metal atoms, so that these metal atoms are deposited and crystallized to form a coating, that is, the required uniform deposition layer is obtained on the working surface of the repaired plastic mold cavity.
Plasma surfacing machine, plasma spray welding machine, shaft surfacing repair
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Laser Surfacing Repair
Laser welding is welding performed by using a laser beam focused by a high-power coherent monochromatic photon flow as a heat source. This welding method usually has continuous power laser welding and pulsed power laser welding. The advantage of laser welding is that it does not need to be carried out in a vacuum, but the disadvantage is that the penetration is not as strong as electron beam welding. Precise energy control can be carried out during laser welding, so that the welding of precision devices can be realized. It can be applied to many metals, especially to solve the welding of some difficult-to-weld metals and dissimilar metals. At present, it has been widely used in the repair of molds.
Laser cladding technology
Laser surface cladding technology is to rapidly heat and melt the alloy powder or ceramic powder and the surface of the substrate under the action of the laser beam. After the beam is removed, self-excited cooling forms a surface coating with a very low dilution rate and a metallurgical bond with the substrate material. , thereby significantly improving the substrate surface wear resistance, corrosion resistance, heat resistance, oxidation resistance and electrical properties of a surface strengthening method.
For example, after carbon-tungsten laser cladding of 60# steel, the hardness can reach above 2200HV, and the wear resistance is about 20 times that of the base 60# steel. After laser cladding CoCrSiB alloy on the surface of Q235 steel, its wear resistance was compared with that of flame spraying, and it was found that the corrosion resistance of the former was significantly higher than that of the latter.
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Laser cladding can be divided into two types according to the powder feeding process: powder preset method and synchronous powder feeding method. The effects of the two methods are similar. The synchronous powder feeding method has the advantages of easy automatic control, high laser energy absorption rate, and no internal pores, especially cladding cermets, which can significantly improve the crack resistance of the cladding layer, so that the hard ceramic phase can be in The advantages of uniform distribution in the cladding layer.
1 The characteristics of laser cladding
(1) The cooling rate is fast (up to 106K/s), which belongs to the rapid solidification process, and it is easy to obtain a fine-grained structure or produce new phases that cannot be obtained in an equilibrium state, such as unstable phases and amorphous states;
(2) The coating dilution rate is low (generally less than 5%), and it has a firm metallurgical bond or interfacial diffusion bond with the substrate. By adjusting the laser process parameters, a good coating with a low dilution rate can be obtained, and the coating composition and Controllable dilution;
(3) The heat input and distortion are small, especially when high power density rapid cladding is used, the deformation can be reduced to within the assembly tolerance of the parts;
(4) There are almost no restrictions on powder selection, especially for depositing high-melting-point alloys on the surface of low-melting-point metals;
(5) The thickness range of the cladding layer is large, and the coating thickness is 0.2-2.0mm in one pass of powder feeding;
(6) It can carry out selective welding, with less material consumption and excellent cost performance;
(7) Beam aiming can make inaccessible areas clad;
(8) The process is easy to automate, and it is very suitable for the wear and tear repair of common wearing parts.
