Design and Analysis of Topologically Ordered Open-Cell Metal Foams by Rapid Manufacturing

Metal foams are structured cellular material which is characterized by their porosity. In recent times, the study of metal foams has attracted researchers owing to their desirable properties. Metal foams with random orientation of pores result in unpredictable properties. Therefore, the metal foams must be topologically ordered. In this research work, a novel rapid manufacturing process comprising of polymer additive manufacturing and pressure-assisted metal powder sintering is used to produce ordered open-cell metal foams. An inverse honeycomb structure is printed with polycarbonate (PC) material using the FDM process. The polycarbonate part is then placed in a customized die and filled with aluminum (Al) metal powder. The Al powder is then sintered from room temperature to 600 °C at the rate of 10 °C/min with a constant pressure of 35 MPa. The maximum compressive strength of PC was found to be within this limit. It is inferred that at 350 °C, the PC melts and flows via the die-channel. Thus, Al powder sinters to produce honeycomb structured metal foam with unidirectional pores. Numerical simulation is used to visualize the liquid fraction contours at various temperatures and flow times of the material PC.