The Council for Science and Industrial Research has developed and patented a rheocasting
process. The process involves the preparation of semi-solid slurries from liquid metal, by controlled
cooling and MHD stirring using induction coils. An industrial prototype was designed and built to
test the system in an industrial environment.
A semi-solid high pressure die casting cell was set up with an industrial partner and the system was
tested under normal production conditions. The production cell consisted of the CSIR rheocasting
system, a six axis robot, dosing furnace and 400 ton H-400SC shot controlled Bühler HPDC machine.
An engine mounting bracket originally designed for liquid HPDC was redesigned for SSM forming
(casting) taking into consideration the flow and thermal behaviour of semi-solid casting process, the
function of the component and the required mechanical properties. Although a full production run
was not completed due to an ancillary equipment failure, sufficient castings were produced to perform
preliminary evaluation of the components. The processing parameters used were, die temperature of
250°C, SSM casting temperature of 580°C ±1Cº and a piston injection velocity of 0.13 m/s. Initial
evaluation showed evidence of casting defects due to a combination of factors: die
design/manufacture, casting parameters and poor foundry practice. From the mechanical tests it was
evident that if the die design, casting parameters and foundry practice are optimized components with
adequate mechanical properties can be reliably produced.
Preliminary evaluation of the feasibility of using polypropylene fibres from COVID-19 single-use face masks to improve the mechanical properties of concrete