MATERIALI IN TEHNOLOGIJE, vol.50, no.3, pp.433-437, 2016 (SCI-Expanded)
Effects of melt stirring and holding time were studied with an Al-4.5 % of mass fractions of Cu (A206) alloy. The optimum
level of a grain refiner was determined in conjunction with both continuously stirred and non-stirred melts during the holding
time. Results showed that a mass fraction of a Ti addition of as low as 0.03 % was sufficient to obtain the 82 μm average grain
size, while a Ti addition exceeding the mass fraction of 0.03 % showed no significant effect on the grain size of castings. The
grain refinement tends to fade with a long holding time in a non-stirred liquid. The results also showed that an effective grain
refinement of the A206 alloy can be achieved with a long holding time as long as the liquid alloy is continually stirred.
Keywords: grain refinement, melt stirring, holding time, Al-4.5Cu alloy, A206 alloy