Micro-Channels in Porous Aluminum Fabricated by NaCl Space Holder Method

Micro-channels in porous aluminum fabricated by the NaCl space holder method has been studied for the first time in this work. According to the material fabrication characteristics, the influence of two sets of technological processes and five kinds of process parameters was studied. The dissolution rate of NaCl particles was used to characterize the state of micro-channels indirectly and wholly and combined with the traditional direct and regional characterization methods to conduct a comprehensive study. It was found that there were three types of micro-channels in the fabrication process: gap-micro-channel, crack-micro-channel, and reticulation-micro-channel. The three types of micro-channels had significant differences in size and quantity and presented various states in different processes. Moreover, the participation of NaCl in sintering inhibited the formation of reticulation-micro-channels but promoted the formation and development of gap-micro-channels and crack-micro-channels. The NaCl particle content and size, sintering temperature, and compaction pressure can affect the micro-channels, but the sintering time cannot.