Scientists from the University of Texas A&M and the U.S. Air Force say they are developing a new way to make 3D printing of the strongest types of steel and other metals. This process using a laser melted steel powder follows the traces of technologies such as welding powder. The researchers used a mathematical model in the process to measure which laser settings would minimize printing defects, and obtained highly strong steel products obtained with 3D printing. The mathematical model and its results are presented in the research team’s article as an ‘optimization system’. Mathematical model saves steel in the production process Experts state that the mathematical model saves the calculation process. So the new idea saves a lot of time compared to a traditional iterative or permutational algorithm that can last almost forever. The team first used the system on an example of a laser melting (SLM) additive made from corrosion-resistant steel called AF9628. With the applied method, dense and powerful samples were successfully produced on a wide variety of process parameters and an SLM processing map was created for AF9628. The printed samples showed tensile strength up to 1.4 GPa for any 3D printed alloy. This figure describes the highest robustness ever achieved. The carbon in the structure of the steel can be quite fragile, and the techniques used in the production of additives can reveal imperfections called porosity. “Pores are small holes that can sharply reduce the strength of the printed 3D object, even if the raw material used for 3D printing is very strong,” said researchers Ibrahim Karaman. Experts used research techniques in dust and other types of welding to minimize pores. The metal powder was heated to form the binder between the two metal pieces. The researchers have adapted a source model to change the number of laser pulses per second and the power of the laser to improve 3D printing patterns and make precise adjustments. In each trial, they tried to figure out if the latest models were working well. The study enables steel producers to save development time and the materials they spend while experimenting with 3D printing. In addition, ultra-hard carbon steels obtained with 3D printing can be a great innovation for the industry.
