Late News Poster Session: Additive Manufacturing
Program Organizers: MS&T Administration, MS&T PCC
Tuesday 4:45 PM
October 19, 2021
Room: Exhibit Hall B
Location: Greater Columbus Convention Center
Poster
P3-10: Additively Manufactured 718 Ni Alloys with Oxide Nanoparticles: Benjamin Stegman1; Xinghang Zhang1; Haiyan Wang1; Bo Yang1; Zhongxia Shang1; Jie Ding1; Tianyi Sun1; William Jarosinski1; Jack Lopez1; 1Purdue University
While direct metal laser sintering (DMLS) has been thoroughly explored in many workhorse alloys, oxide dispersion strengthening (ODS) alternatives of these alloys have presently had little investigation. Here we report on an ODS alloy 718 (718) successfully developed by mixing oxide powders with control 718 powders to produce a homogeneous distribution of oxide nanoparticles, which then were used in the DMLS technique. This newly developed metal matrix composite (MMC) was investigated under various forms of material characterization, ranging from X-ray diffraction to transmission electron microscopy to analyse microstructures and chemistry from macroscale to nanoscale. This study reveals the prominent differences between control 718 and this new ODS alloy, and how the presence of oxide nanoparticles alters the microstructure and mechanical behaviors. This new processing technique demonstrates the possibilities of using DMLS to fabricate ODS alloys for applications in extreme evironments.
P3-11: CALPHAD-based Alloy Design and Uncertainty Quantification for Additive Manufacturing: Xin Wang1; Soumya Sridar1; Wei Xiong1; 1University of Pittsburgh
During powder production, the pre-alloyed powder composition often deviates from the target composition leading to undesirable properties of additive manufacturing (AM) components. Therefore, we developed a method to perform high-throughput calculation and uncertainty quantification by using a CALPHAD-based ICME framework (CALPHAD: calculations of phase diagrams, ICME: integrated computational materials engineering) to optimize the composition, and took the high-strength low-alloy steel (HSLA) as a case study. We analysed the process-structure-property relationships for 450,000 compositions around the nominal composition of HSLA-115. Critical properties, such as yield strength, impact transition temperature, and weldability, were evaluated to optimize the composition. An optimized composition has been determined, which increased the probability of achieving successful AM builds by 44.7%. The present strategy is general and can be applied to other alloy composition optimization to expand the choices of alloy for additive manufacturing. Such a method also calls for high-quality CALPHAD databases and predictive ICME models.
P3-13: Effect of Heat Treatment on Microstructure and Corrosion Behavior of Additively Manufactured 7050 Aluminum Alloy: Rupesh Rajendran1; Preet Singh1; 1Georgia Institute of Technology
The additively manufactured 7xxx series aluminum alloys are promising candidates for aerospace industry due to the inherent advantages of additive manufacturing process in addition to the light weight and high strength properties of these alloys. Recent nanoparticle or inoculant addition has mitigated the problems of solidification defects which limited a wider adoption of these alloys. However, the corrosion behavior of these alloys as a function of heat treatment remains largely unexplored. This work aims to understand the microstructure and corrosion behavior of 7050 aluminum alloy, fabricated via Selective Laser Melting(SLM) process, and heat treated with different ageing durations. General and localized corrosion behavior is studied and compared with an equivalent wrought 7050 alloy. The results showed that SLM alloys have less corrosion susceptibility and pitting, in general, compared with the equivalent wrought alloys. The effect of ageing duration on microstructural features, responsible for the difference in corrosion behavior is identified.