Need castable material.

[JimMetalsCeramics]

I'm looking a a material which is easily castable and easy to disntegrate. It should have an expansion coefficient <8 ppm/°C. A polymer matrix composite might be nice. Cost is a factor.

 

[kenvlach]

Polystrene meets the requirements except for low CTE. It is a very common mold material for metal casting as it is very low density and vaporizes/burns when hit by the liquid metal (if that is what you are doing).

Other plastics with the requisite low CTE are ABS, acrylic, polycarbonate, polyimides and some epoxies (e.g., novolacs), but these are far more difficult to remove than polystyrene.

 

[JimMetalsCeramics]

Any polymer should disintegrate if I bake it at high enough temperature. But the material has to have low CTE, ideally <6 ppm/C.