From Angel Food Cake to Porous Titanium – A Novel Powder Metallurgical Approach for Metallic Foam Utilizing Food Processing and Ceramic Processing Techniques

Abstract

Porous Ti6Al4V was attempted to be produced by using the protein forming method. This study characterizes slurry compositions and processing parameters aimed to obtain porous Ti6Al4V with open porosity, an interconnected porous networks and controllable pore size. Laboratory egg white powder was used as a binding and a foaming agent. A porous Ti6Al4V green body was produced through a gelling process at 80°C and a drying process at 120°C. A good strength porous Ti6Al4V specimen is available after a protein burnout process in an air atmosphere and a sintering process in a vacuum environment. Optical microscopy was performed on the porous Ti6Al4V specimens after each processing step to inspect their porous structure. Carbon and oxygen contents were also analyzed in the specimens during intermediate processing steps. Optimal temperature for protein burnout process is identified to be between 400°C to 450°C for an egg white concentration in the range of 6vol% - 24vol%. Pore sizes approximately 200–700 μm were observed after the sintering process. These experimental results demonstrate prospects on fabricating porous titanium and other metals using the protein forming method.