Stacking Carbide
Stacking Carbide
Die Die Die Die Failure and maintenance
Methods to improve the service life of die casting mold
Die Casting As long production cycle, large investment and manufacturing of high precision, therefore high cost, so we have a higher mold life. However, materials, machining and a series of internal and external factors, leading to premature failure and die scrap, resulting in tremendous waste.
Failure of die casting mold forms are: sharp corners, corner cracking, splitting, thermal cracking (cracking), wear, erosion and so on. Die casting mold caused by failure of the main reasons are: inherent defects in material, processing, use, maintenance and treatment problems.
1, material defects in their
As we all know, the use of die casting mold extremely harsh conditions. With aluminum die-casting mold, for example, aluminum melting point 580-740 , use, temperature control of molten aluminum in the 650-720 . In the case of not casting mold preheat, cavity surface temperature rose from room temperature direct liquid temperature, the cavity surface of the enormous tensile stress. Top mold piece, the cavity surface of the enormous stress. Thousands of die-casting, the mold surface can lead to cracking and other defects.
Thus, an acute die-casting thermal quench conditions of use. Mold material should be selected thermal fatigue resistance, fracture toughness, thermal stability, high thermal die steel. H13 (4Cr5MoV1Si) is applied over a wide range of material, It is reported that 80% of the cavity abroad are used H13, is still a large number of domestic use 3Cr2W8V, but 3Cr2W8VT_ arts performance is not good, poor thermal conductivity, linear expansion coefficient is high, work have a great thermal stress, resulting in cracks or even break mold, and heating trade decarbonization to reduce die wear resistance, so are out of steel. Maraging steel applied to heat cracking and wear resistance and corrosion resistance of less demanding on the mold. Heat-resistant alloy of tungsten and molybdenum is limited to more severe thermal cracking and corrosion of small inserts, although the alloy is brittle another notch sensitivity, but the advantage of good thermal conductivity, but can not be set on the need for cooling of the thick channel die casting die casting mold has a good adaptability. Therefore, reasonable under the heat treatment and production management, H13 still has satisfactory performance.
Manufacture of die casting mold material, regardless of where one should be consistent with the design requirements to ensure that die-casting mold used in its normal condition to meet the design service life. Therefore, production before the series deal with materials inspection, in case of defected material, resulting in mold costs of early retirement and processing waste. Corrosion inspection tools are commonly used in macro-examination, metallographic examination, ultrasound examination.
(1) macro-corrosion inspection. Mainly the porous material, segregation, cracking, cracks, and crack the surface of the hammer, joints.
(2) metallographic examination. Mainly the grain boundary carbide material segregation, distribution, crystal Liaodu and grains inclusions.
(3) ultrasound. Mainly the defects inside the material and size.
Second, die casting mold processing, use, repair and maintenance
Die Design Handbook has been described in detail the design of die casting mold problems should be noted, however, in determining the injection speed, the maximum speed should not exceed 100m / S. Speed is too high to promote corrosion and mold cavity and core the sediment increased; but too low to make casting defects easily. So for magnesium, aluminum, zinc and the corresponding speed of most low shot 27,18,12 m / s, the maximum injection speed of aluminum should not exceed 53m / s, the average injection speed 43m / s.
In the process, the thick overlay the template method can not guarantee its thickness. 1 times as thick steel plate, bending deformation is reduced by 85%, stacking can only play a role in stacking. Veneer thickness and the same two plates in bending deformation is 4 times the veneer. Also in the process cooling water, the two sides should pay particular attention to ensure processing concentricity. If you head around the corner, not concentric with each other, then use the process, the connection will be cracking around the corner. The surface of the cooling system should be smooth, preferably machined without leaving traces.
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Where can I purchase a saw blade sharpener?
Over the years, I have accumulated a stack of 10 inch carbide and steel saw blades for my saws. I hate to throw them out, but it is cheaper to buy a new one than have one sharpened by a tool store.
Anyone know where I can purchase a saw blade sharpener for home use?
Foley and Belsaw (now one company) have been selling saw sharpening equipment for years. Check eBay and Craigs list for used saw sharpening equipment. Personally I wouldn’t bother. Cheap carbide blades aren’t worth sharpening, steel blades aren’t worth owning anymore and good carbide blades should be sent to a professional service like Forrest.
Take your old blades and recycle them or turn the into clocks or wall decorations.