The new idea of using additive manufacturing to design unique heterogeneous alloys with novel microstructure and excellent properties opens up a new manufacturing field for the design of titanium alloys. This can not be realized by traditional manufacturing methods, and has a wide range of structural applications.
Most people think that 3D printing is a revolutionary technology that can produce complex shaped machine parts in one step; However, the research team revealed that it has important potential for designing materials beyond simply printing shapes.
Metallurgists generally believe that alloys that lack uniformity will lead to brittleness. One of the key issues in the additive manufacturing process is how to eliminate this non-uniformity during rapid cooling. His team found that having a certain degree of heterogeneity in a component can actually produce unique and heterogeneous microstructure that enhances the properties of the alloy. The proposed method uses a focused laser beam to melt and mix two different alloys, namely titanium powder and stainless steel powder. By controlling the laser power and its scanning speed isoparams during the 3D printing process, the team succeeded in printing the new alloy with non-uniform composition in a controlled manner.
In addition to the use of additive manufacturing, the composition of the two powder mixtures is another key to creating a previously unknown lava-like microstructure with high metastability in the new alloy. These unique microstructures make the alloy very strong and ductile.
While stainless steel usually weighs 7.9 grams per cubic centimeter, the new alloy is only 4.5 grams per cubic centimeter, a weight reduction of about 40 percent. Titanium alloys with lava-like microstructure exhibit high tensile strength of about 1.3 gigapascals and uniform elongation of about 9%. It also has an excellent work hardening capability of more than 300 mpa, which guarantees a large safety margin before fracture, which is useful in structural applications. These excellent properties are expected to be used for structural applications in a variety of scenarios in the aerospace, automotive, chemical and medical industries. Titanium alloys are very strong and have good ductility and low density.
