Optimization of sand-casting process parameters on the hardness of locally-made corn-mill grinding plates

Sand casting process parameters such as moisture content (%), sand particle size (mm), pouring time (sec) and pouring temperature (℃) were investigated to determine their influence on the hardness of the locally made corn mill grinding plates made from high chrome cast iron. The process parameters were varied from 2.0% − 8.3% for the moisture content, 0.15 mm − 10 mm for sand particle size, 1350 ℃ − 1450 ℃ for pouring temperature, and 8 sec − 10 sec for pouring time. Also, two level four factor ( \(\:{2}^{4}\)) full factorial design was used in the investigation and the experiment was replicate twice to yield a total of thirty-two (32) as-cast samples. In the investigation, it was found that, manufacturing process parameters like the pouring temperature (℃), pouring time (sec), moisture content (%), and sand particles size (mm) are the most significant factors contributing to the hardness of the locally made corn mill grinding plates. It was also established from the experiment that, decreasing the pouring temperature (℃), pouring time (sec), moisture content (%), and sand particle size (mm) resulted in an increase in hardness. Furthermore, the optimized value for manufacturing the locally made corn mill grinding plates was find to be 8.0 sec for the pouring time, 1350 ℃ for the pouring temperature, 2.0% for the moisture content and 0.150 mm for the sand particle size producing a hardness value of 47.0 HRC. The study also revealed that, there are interactions in all the sand-casting process parameters selected for the experiment except pouring temperature and pouring time.