QUANTIFICATION OF THE SICP CONTENT IN MOLTEN AL-SI/SIC{sub}P COMPOSITES THROUGH COMPUTER AIDED THERMAL ANALYSIS

摘要

The aim of this work is to explore the feasibility of the computer aided thermal analysis as a tool for SiC{sub}p content quantification in molten Al-Si/SiC{sub}p composites. This technique was applied to three cases of interest: (1) the metal matrix alloy A356, without SiC{sub}p particle reinforcement; (2) A356/ 8% SiC{sub}p MMC and (3) A356/18%SiC{sub}p MMC. The tests were performed in order to identify, within the commonly used thermal analysis parameters, the parameters that could be used for SiC{sub}p content quantification. In this regard, the parameters: eutectic temperature, TEG, and local solidification time, ts shows clears trends and low dispersion in its changes as a function of SiC{sub}p content. It is found that an increase in SiC{sub}p content produces a statistically significant increase of TEG and a decrease of ts. The behavior of ts may be explained as a result of the decrease of the latent heat released during solidification as the SiC{sub}p content is increased, as indicated by the latent heat data obtained from Newton thermal analysis (NTA) applied to the experimental cooling curves. A simplified analysis of the experimental results indicates that, under the experimental conditions used in this work, the best resolution that could be expected from this method is around ±1.3 Vol.% of SiC{sub}p content, when the local solidification time is chosen to quantify the particle content of Al-Si/SiC{sub}p composites.