Investigation of the effect of holding time and melt stirring on the grain refinement of an A206 alloy

Abstract

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.