Statistical analysis using multiple regression of stereological parameters for skeleton castings microstructure

In this article authors showed influence of technological parameters and modification treatment on structural properties for closed skeleton castings. Approach obtained maximal refinement of structure and minimal structure diversification. Skeleton castings were manufactured in accordance with elaborated production technology. Experimental castings were manufactured in variables technological conditions: range of pouring temperature 953÷1013 K , temperature of mould 293÷373 K and height of gating system above casting level 105÷175 mm. Analysis of metallographic specimens and quantitative analysis of silicon crystals and secondary dendrite-arm spacing analysis of solution α were performed. Average values of stereological parameters for all castings were determined. (B/L) and (P/A) factors were determined. On basis results of microstructural analysis authors compares research of samples. The aim of analysis was selected samples on least diversification of refinement degree of structure and least silicon crystals. On basis microstructural analysis authors state that samples 5 (AlSi11, T_pour 1013K, T_mould 333K, h – 265 mm) has the best structural properties (least diversification of refinement degree of structure and the least refinement of silicon crystals). Then statistical analysis results of structural analysis was obtained. On basis statistical analysis autors state that the best structural properties for technological parameters: T_pour = 1013 K, T_mould = 373 K and h = 230 mm [4]. The results of statistical analysis are the prerequisite for optimization studies.