Researchers have found a way to predict the effectiveness of 3D printing martensitic steel.
3D Printing Martensitic Steel
Martensitic steel is a form of the material that is significantly stronger due to the microstructures formed by the molecules. Traditionally martensitic steel is made by quenching very hot steel, and this rapid cooling causes the required microstructures to form.
This is a bit problematic for metal 3D printers, which don’t exactly have the ability to quickly quench freshly fused metal powder in the midst of a long print job.
Instead of quenching, metal 3D printer operators tweak the available settings to approximate conditions that could lead toward the production of stronger microstructures. But it’s hard to do this because it can require a considerable amount of experimentation.
Metal 3D Printing Parameters
Now researchers from Texas A&M University have found what could be a solution to this dilemma. In a report from the University, Dr. Ibrahim Karaman, Head of the Department of Materials Science and Engineering, said:
“Strong and tough steels have tremendous applications but the strongest ones are usually expensive — the one exception being martensitic steels that are relatively inexpensive, costing less than a dollar per pound. We have developed a framework so that 3D printing of these hard steels is possible into any desired geometry and the final object will be virtually defect-free.”
The problem here is porosity. Typical attempts at 3D printing strong metals tend to result in a porous print. While the metal portions may be stronger, the porosity introduces weakness, and overall the strength is not what is desired.
The researchers took a cue from the welding industry, where existing models could predict the strength of a melt scenario. They compared the results of this prediction with a 3D printing scenario and gradually adjusted the formula to enable proper predictions based on real results.
Texas A&M University says:
“After a few such iterations, their framework could correctly forecast, without needing additional experiments, if a new, untested set of laser settings would lead to defects in the martensitic steel. The researchers said this procedure is more time-efficient.”
They were able to produce a kind of map that shows how 3D print parameter settings would affect a given scenario, as shown here.
Optimizing All Metal 3D Printing
This gets better. Dr. Karaman explained further:
“Although we started with a focus on 3D printing of martensitic steels, we have since created a more universal printing pipeline,” said Karaman. “Also, our guidelines simplify the art of 3D printing metals so that the final product is without porosities, which is an important development for all type of metal additive manufacturing industries that make parts as simple as screws to more complex ones like landing gears, gearboxes or turbines.”
This is incredible news for metal 3D printing operations, which could, if this method is made available, optimize 3D print settings much more quickly to achieve better print results.