Response surface mResponse surface methodology for modelling of thixotropic microstructural characteristics of semi-solid 7075 alloyethodology for modelling of thixotropic microstructural characteristics of semi-solid 7075 alloy

چکیده مقاله

In this study, a newly modified strain-induced melt activation (SIMA) process was used to the semi-solid processing of 7075 aluminum alloy.  Response surface methodology (RSM) was applied to investigate the effects of newly modified SIMA process parameters on thixotropic microstructural characteristics of semi-solid samples. The responses, which involved the average grain size and the shape factor, were considered as a function of three independent input variables: effective strain, isothermal holding temperature and time. The developed mathematical models were examined by the analysis of variance (ANOVA) method to check their adequacy. A comparison was also made between experimental and calculated results, which were found to be in good agreement. It was found that all the first- and second-order terms of the independent parameters and the interactive terms of the effective strain and holding time were statistically significant for the responses. Overlaid contour plots was used to simultaneously optimize the responses. An average grain size between 40 and 50 μm and a shape factor between 0.80 and 0.85 were achievable under the optimum conditions.

دریافت لینک دانلود مقاله