Common Defects Of Wax Mold In Precision Casting And Its Solution
Common Defects of Wax Mold in Precision Casting and Its Solution
Wax mold production is the key link in the precision casting process, the quality of the wax mold will directly affect the quality of the casting, the following is my factory technical staff summary of the common mistakes and its solution:
1, wax mold deformation, wax mold removed from the mold, in addition to the size of the narrowing changes, and sometimes because of the wrong way when the man-made deformation caused by man-made; because the wax in the cooling over the deflection is common, so Just remove the wax from the pressure type still careful to place, usually with a larger plane as the base plane flat, the other may also be too soft wax, pressure design and other factors caused by unreasonable.
2, wax mold filling dissatisfaction, the main reason is the wax material temperature is too low, the injection speed is slow, low pressure temperature, resulting in wax flow in the process of cooling fast, the performance of the corner and the edge of the wax or thin Wall part of the full dissatisfaction, angular corners appear fillet, Precision Casting this situation is very similar to the casting of metal castings.
3, wax mold surface wrinkles, because the wax material temperature is too low, the rate of fire is too low, wax material movement and pressure-type temperature with improper; or due to pressure on the inner surface damage or not clean; chilled metal block placed improper, Leaving traces of movement on the wax mold surface. Deep lines, similar to the cold deformation of metal castings; there is around the core, around the hole, Precision Casting and sometimes can be seen seams, slightly depression, the actual two shares of wax flow at the rendezvous failed to fuse well Is the temperature of the wax material is not enough, the result of insufficient pressure.
4, wax mold surface depression, mainly the injection pressure and time is not enough, or wax material temperature is high, the cooling time is insufficient, sometimes off the release agent too much, the surface depression involving a larger area, repair more difficult, easy to cause Waste.
5, wax mold there is a seam, which is the most common one of the defects, that is, in the pressure type, the combination of pressure-type block, the core and the core of the junction and other places have a thin wax Out. The main reason is that the pressure is not enough precision, pressure type or internal parts of the joint surface is damaged or attached to the unclean material, or the type of force is not enough, the injection pressure is too high. Or the temperature of the wax is too high. Wings must be completely removed, wax mold can be used.
6, wax mold and pressure type adhesive, this is because there is no use of release agent, or wax and pressure of the temperature are too high, Precision Casting or the pressure inside the surface is not clean enough.
7, wax mold surface rough, because the injection pressure is too low, or lower firing rate of wax and the pressure of the inner surface of the contact density is not enough, there will be serious folds.
8, wax mold bubbles, one is visible with the surface of the surface bubbles, and the other is the wax inside the bubble, usually larger, Precision Casting with the naked eye can not see, but can be found through the local pattern of wax mold, This is due to the expansion of gas within the wax mold.