As those within the rapid prototype making industry all know. The nature of CNC Machining material differs greatly from that of 3D Printing material.
CNC Machining is used in the production of many complex three-dimensional shapes. It is because of these qualities that CNC Machining is used in jobs that need a high level of precision or very repetitive tasks. With great hardness, resistance to abrasion.
Vacuum Casting (Silicon Molding)
The quality of the product made by the Vacuum Casting is not as good as that of CNC machining, but it has a great advantage in price. But not all products available to choose the way of processing. This should be based on your requirements for product performance, cause it has certain risk. Generally it’s available of small size products , and with low price, but easy to deformation. The larger size of the product is easy to shrink. The product that comes out is relatively brittle.
Moreover, the temperature tolerance is about 80 degrees of the Vacuum Casting products. Therefore, if there is a high temperature requirements, it is not recommended to use a Vacuum Casting processing. Mainly depends on the your to the product performance request.
Suggest Reading: What's the difference between CNC Machining and 3D Printing?