A metallography coupled with the microprobe method was used to study the solidification process of superalloys. It was found that the final solidification temperatures of the conventional superalloys are generally very low, about lOtSO-112OC, the solidification ranges are large enough, reaching 180-24OC, that makes the solidification segregation serious. Strictly controlling the contents of the minor elements P,Zr,B and Si in superalloys can raise the final solidification temperature to 1180-1280°C and contract the solidification temperature range to 50-12O"C, that results in alleviating the solidification segregation obviously. After controlling the contents of the minor elements, a series of new superalloys with low segregation and excellent properties have been developed.

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Segregationdue to solidification of highly alloyed superalloy is a very complex process.

Introduction: Charged aerosol detection (CAD) has the merits of high sensitivity, high universality and response uniformity. The strategy that combines the quantitative analysis of multi-components by single marker (QAMS) with CAD has certain advantages for the quantification of multi-components. However, relevant research was limited.Objectives: To comprehensively investigate the crucial factors that affect the performance of the HPLC-CAD-QAMS approach and validate the credibility and feasibility of the method.Methodology: Multiple components of Qishen Yiqi dripping pills (QSYQ) were assayed using the high-performance liquid chromatography (HPLC)-CAD-QAMS approach. Some factors that affect the sensitivity and accuracy of the approach were sufficiently studied. After the method verification, principal component analysis (PCA) was applied to evaluate the quality consistency of three types of samples: normal samples, expired samples and negative samples. Results: A HPLC-CAD-QAMS method was successfully developed for the multicomponent determination of QSYQ. First, chromatographic conditions were optimised by a definitive screening design, and the optimised ranges of operating parameters were obtained with a Monte Carlo simulation method. Next, a new method to select the internal reference standards was successfully introduced based on the heatmap of Pearson correlation coefficients of the response factors.Then, the multi-point method was selected to calculate the relative correction factors, and a robustness test was conducted with Plackett-Burman design. Finally,