1. Modeling materials
Generally speaking, cast titanium molding materials should have the following characteristics and requirements: high chemical inertness, high refractoriness and thermal shock resistance, high enough strength, uniform and fine materials, small adsorption capacity for moisture and gas, and low thermal conductivity , Low price, non-toxic.
Second, the modeling process
The molding process of titanium plates and titanium castings includes hard mold casting, graphite tamping, melting model and lost model.
(1) Hard mold casting includes graphite processing type casting and metal type casting. The life span of Shilikou molds can be up to 3 to 10 times, and some combined graphite processing life can be up to 30 to 40 times. It is suitable for static casting and also for centrifugation, but only titanium alloy castings with a wall thickness greater than 10 mm are suitable for the graphite process. The metal mold casting process is simple, the casting size is relatively accurate, and the production cost of small castings is low. The disadvantage is that cold and flow marks often appear on the surface of the casting, and a brittle layer exists on the surface of the casting.
(2) The process method of graphite tamping is the same as that of ordinary sand casting, and high-purity artificial graphite powder is used as molding sand. Most of the castings used in chemical industry, especially: Mei is a large casting, which is cast using graphite tamping.
(3) Investment precision casting, also known as lost wax casting, casting size fine stone corners, smooth surface, can cast complex shapes of castings, can improve the utilization rate of metal materials, high production flexibility, strong adaptability.
(4) The lost foam (EPS foam type) casting process is to combine the foam model with the size similar to the casting into a model cluster, brush the refractory coating and dry it. The high temperature baking removes the foam model, and then bury the shell model in the dry Vibration in the sand is tight, pouring under the name of vacuum, liquid metal occupies the model position, after solidification and cooling to form castings, EPS disappears. Model shell casting can produce large structural parts that wax molds cannot.