Fig. 4: Interdendritic phase morphology characterization in the melting zone fabricated with the ER2319 and the ZCASW filler materials.

a, b Interdendritic phase in the melting zone fabricated with the ER2319 and the ZCASW filler materials. c Comparison of interdendrictic phase area fractions obtained from different melting zones (Error bars represent standard deviation). d EPMA maps showing the chemical constitutions of the interdendritic phase and Al matrix in the melting zone fabricated with the ZCASW filler. e Interdendritic phase observed by TEM-EDX, showing a STEM-HAADF image. f SAED pattern of the interdendritic phase. g EDX mapping of the main elements (Al, Cu, Mg and Zr). h HRTEM image of the interface between α-Al and Mg₂Cu phase, with the inset showing the FFT pattern of Mg₂Cu phase.