Preparation, characterization and designing of porous Ti–6Al–4V through metal injection molding without space holder

Porous Ti–6Al–4V alloys have been widely applied in industry, serving as structural or functional materials. However, the conventional method of producing porous Ti–6Al–4V by metal injection molding (MIM) with space holder has several drawbacks, such as long debinding time, sintering furnace contamination, uncontrolled porosity and pore size, poor mechanical properties and process instability. This study presents a novel method of fabricating porous Ti–6Al–4V by MIM without space holder that can overcome these challenges. The porosity, average pore size, tensile strength, and compressive strength were studied by scanning electron microscope characterization, optical micrograph analysis, and mechanical testing. Flexible changes in porosity (17 %–74 %), pore size (14 μm–84 μm), and tensile strength (15 MPa–457 MPa) could be achieved by adjusting the powder size and sintering temperature. A higher porosity can be achieved as compared to the previous studies. The relationships among particle size, sintering temperature, porosity, and tensile strength are investigated by multiple regression models, which facilitate the tailored design of porous Ti–6Al–4V alloys for industrial applications and enhance the combination of experimental and theoretical methods in the design of porous alloys using MIM.