February 2023 Volume 5

FORGING RESEARCH

small holes inside of the metal particles. This was not seen in the vacuum sintered part.

This project investigated the feasibility of additive manufacturing processes (such as binder jet) to minimize cycle time in the forging operations. We have studied the effect of processing parameters on microstructure and mechanical behavior of 316 stainless steel fabricated via binder jet followed by forging. The results are interesting, however further investigation is required. We have completed this initial work under a FIERF Micro-grant and continuing this work where we are going to explore other additive manufacturing processes such as selective laser melting to fabricate forging preforms under a FIERF Stage Grant. Also, we are working towards a closed-die part with comparable strength and grain flow to traditionally forged parts. To view the full report – visit the FIA website. Acknowledgment: This work is financially supported by Forging Industry and Educational Research Foundation (FIERF). Authors acknowledge the support of Canton Drop Forge for conducting open die forging experiments. References: 1. Saereh Mirzababaei, Somayeh Pasebani, 2019, A Review on Binder Jet Additive Manufacturing of 316L Stainless Steel. 2. Saereh Mirzababaei, Brian K. Paul, Somayeh Pasebani, 2020, Metal Powder Recyclability inBinder Jet AdditiveManufacturing. 3. Uduwage, Don Suranga Dhanushka, "Binder Jet Additive Manufacturing of Stainless Steel-Hydroxyapatite Bio-composite" (2015). All Theses, Dissertations, and Other Capstone Projects. Paper 432. 4. Amelia Elliott, Sara AlSalihi, Abbey L. Merriman, Mufeed M. Basti, 2016, Infiltration of Nanoparticles into Porous Binder Jet Printed Parts. 5. Alta C. Bailey, Abbey Merriman, Amelia Elliott, Mufeed M. Basti, 2016, Preliminary Testing Of Nanoparticle Effectiveness In Binder Jetting Applications. 6. Jujie Yan, Yinghao Zhou, 2019, A Comprehensive Study of Steel Powders (316L, H13, P20 and 18Ni300) forTheir Selective Laser Melting Additive Manufacturing. 7. Y. Tang, Y. Zhou, T. Hoff, M. Garon, Y. F. Zhao, 2016, Elastic modulus of 316 stainless steel lattice structure fabricated via binder jetting process.

(a) VacSintered

(b) Z-Axis

(c) Z+X-Axes

Figure 2 Figure 3 shows microhardness and Rockwell hardness test results of forged and vacuum sintered samples. With all three samples, the porosity of the material created issues for consistent data as some sections of the sample have less support behind the surface than others, in addition to particle boundaries creating some additional inaccuracies. As we can see fromFigure 3 (a),The Vicker’s hardness results show the Z+X Axes forged sample have the highest microhardness and the Vacuum Sintered sample shows the lowest microhardness across the board. However, in Figure 3 (b), we can see with the greater surface area of the tester, the Rockwell test shows a better average of the surface and the denser Vacuum Sintered sample proves the highest overall hardness compared to the forged samples. None of the samples were showing 100%density thus none of the samples provide full hardness of a normal fully dense piece of SS316L.

Figure 3 (a)

(b)

FIA MAGAZINE | FEBRUARY 2023 75