3D-Printed Parts Said to Outperform 17-4 PH Stainless Steel

Cylinders 3D-printed by ITAMCO from EOS 17-4 PH powder were found to have higher tensile strength than raw material 17-4 PH that had been heat treated.

ITAMCO (Indiana Technology and Manufacturing Companies) has 3D printed parts made with EOS 17-4 PH IndustryLine metal powder that outperformed 17-4 PH stainless steel in tensile strength in a recent research project.

The goal of the research project was to explore the properties of additive-manufactured
parts made with the new EOS Stainless Steel 17-4 PH IndustryLine metal powder for Direct
Metal Laser Sintering (DMLS). EOS Stainless Steel 17-4 PH IndustryLine is a high-strength, easily curable, highly corrosion-resistant and acid-resistant material, making it ideal for manufacturing surgical and orthopedic instruments.

ITAMCO prepared the build of nine cylinders with Sunata software by Atlas 3D. Sunata automatically chose the best orientation for the parts and generated the necessary support structures for the build on ITAMCO’s EOS M 290 3D printer.

Three cylinders were built horizontally, three were built at a 45-degree angle to the horizontal, and three were built vertically. After the build, the cylinders were cut from the build plate and sent for heat treatment. The heat treatment followed the recommended steps by EOS. First, the cylinders were heated to 1,040˚C and kept at that temperature for 0.5 hr. The cylinders were then quenched by argon. After that, the cylinders were reheated to 480˚C and kept at the temperature for 1 hr. The cylinders were quenched again by argon. The hardness was between 40 and 47 HRC and the estimated tensile strength was 190 KSI after heat treatment.

The cylinders were then shipped to SGS MSi, a metallurgical testing laboratory. The tensile strength of the nine cylinders outperformed the tensile strength of raw material 17-4 PH that had been heat treated. The average tensile strength (PSI) of the nine cylinders was 192,000. The average tensile strength (PSI) of six heat-treated stainless steels (H900, H1025, H1075, H1150, H1150-M, H1150-D) is 144,000.

“We conducted the research so we could compare the wrought properties of metal to parts
made through additive manufacturing with the new EOS 17-4 PH Stainless Steel metal
powder. It is quite amazing to us that we achieved the wrought properties of metal,” says 
Joel Neidig, business development and technology manager with ITAMCO.

Another interesting finding from the research was that although the nine cylinder samples were built with three orientations, the tensile strength, yield strength, elongation and reduction of area were fairly consistent for all the samples. In other words, the material properties are near isotropic for those samples built additively with different build orientations in the EOS M 290 3D printer.