Titanium is a challenge to cast because it is a highly reactive metal and can interact with the atmosphere and with conventional refractory used in molding processes. Casting is a method for fabricating near-net shape components and is particularly cost effective for exotic material such as titanium. As a technology, titanium casting is relatively new and has been a commercially viable practice dating back to the 1970’s. It wasn’t until the 1990’s that castings made up a significant portion of the total weight of titanium product shipped each year, primarily as a result of sporting goods such as golf club heads.
The advantages to titanium castings are cost savings, reduced lead time for delivery, ability to provide complex near-net shapes and the ability to use rapid prototyping to produce evaluation components inexpensively compared with conventional titanium die forging, machining and joining processes.
Titanium castings have been cast in machined graphite molds, rammed graphite molds, and proprietary investments used for precision investment casting. The most common melting method uses vacuum arc re-melting (VAR) into a water cooled crucible and pouring into molds. This practice is more commonly known as Skull Casting. Pouring can be done centrifugally (molds spinning on a turntable) or statically (molten metal poured directly into a mold positioned below the copper crucible). Another melting practice known as cold wall induction (IM) has been used with some success although the equipment costs are somewhat prohibitive.
Ti Squared Technologies has been able to achieve significant design complexity, dimensional accuracy and cosmetic quality using its proprietary pressure- assist static casting process. This method of casting has also proven effective for producing thin walled parts such as turbine wheels and industrial tools. Difficult alloys for fill-out such as gamma-titanium are successfully cast at Ti Squared without the use of a centrifuge.
Our static casting process effectively eliminates porosity that requires HIP to achieve internal soundness. Mold metal reactions causing alpha case and fine grain structure promoting higher strength are controlled through more rapid solidification.
Induction Air Melt cannot be used for titanium.
Titanium must be melted in a vacuum.