Highly reactive metals such as titanium pose particular challenges when casting. The atmospheric conditions in a ‘normal’ vacuum pressure casting machine are completely inadequate for smelting and casting titanium, and the crucibles and moulds need to be made of specific materials. Hence until now the only way to cast titanium was to use extremely expensive specialized machines. As part of a joint AiF ZIM research project, Indutherm has collaborated with the Bergakademie Freiberg under the sponsorship of the Federal Ministry for Economics and Technology (Bundesministeriums für Wirtschaft und Technologie – BMWi) to develop a cost-effective solution for casting highly reactive metals.
The ideal structural basis proved to be the VTC 200 V tilting casting machine. Following numerous modifications, such as completely reconstructed valves and hose connections, special seals and an evacuation and inert gas flushing process tailored to the machine, the prerequisites for the required vacuum of 10-7 bar were met. Furthermore, special crucibles and inductors were developed for the Ti versions, as the ceramic crucibles that are normally used also react with titanium to varying degrees. The new materials also reduce smelting times – and the shorter the smelting time, the less time there is for a possible reaction.
The VTC V Ti machines are not only suitable for casting titanium – they can also be used for any highly reactive metal or alloy, such as copper beryllium etc.