Metal-Matrix Composites: Advances in Processing, Characterization, Performance and Analysis: Additive Manufacturing and Processing of Composite Materials
Sponsored by: TMS Structural Materials Division, TMS: Composite Materials Committee
Program Organizers: Srivatsan Tirumalai; Pradeep Rohatgi, University of Wisconsin; Simona Hunyadi Murph, Savannah River National Laboratory

Monday 2:00 PM
February 28, 2022
Room: 256B
Location: Anaheim Convention Center

Session Chair: Tirumalai Srivatsan, The University of Akron

2:00 PM  Keynote
Additive Manufacturing of Metal Matrix Composites for Structural and Biomedical Applications: Amit Bandyopadhyay1; Susmita Bose1; 1Washington State University
    Additive manufacturing (AM) or 3D Printing (3DP) is an approach to process parts directly from its computer-aided design (CAD) file. AM is changing the landscapes of current industrial practices. On-demand manufacturing using AM technologies is a new trend that will significantly influence many industries and product design protocols. Since there is no need for any part-specific tooling, different parts can be built using the same machine. We have worked on AM of metal matrix composites over the last two decades using the directed energy deposition (DED) and powder bed fusion (PBF) processes. Among others, we have manufactured parts with compositional and functional gradation using Ti alloys, steels, Inconel 718, and tungsten for structural and biomedical applications. This presentation will focus on some of the key success stories from our research and current challenges in the field.

2:30 PM  Invited
Additive Manufacturing of Titanium – Boron Carbide In situ Composites: Mohan Sai Kiran Nartu1; Srinivas Aditya Mantri1; Thomas W. Scharf1; Brandon Mc Williams2; Kyu Cho2; Narendra Dahotre1; Rajarshi Banerjee1; 1University of North Texas; 2CCDC U.S. Army Research Laboratory
    The present study will focus on detailed microstructural characterization and holistic understanding of the sequence of formation of ceramic phases in Laser engineered net shaping (LENS) processing of in situ Ti-B4C composites for high loading fractions, i.e., 25 wt.% and 35 wt.% B4C. Though, both in-situ composites, Ti-25wt.%B4C and Ti-35wt.%B4C were similarly processed via LENS, their as-processed microstructures were drastically different. Ti-25wt.%B4C exhibited nearly homogeneous microstructure, mainly dominated by TiB, TiC and α-Ti phases. Ti-35wt.% B4C exhibited alternatively-repeating layered microstructure with TiB2 and TiC phases in one layer, and TiB and TiC phases with a small fraction of retained-B4C and α-Ti in another layer. Heipel-Roper theory of weld pool dynamics has been employed to rationalize the mechanism underlying the evolution of these layered composites. Further, results from the hardness, wear and compression tests performed, indicate the potential for the AM processed Ti-B4C composites as wear and abrasion resistant materials.

2:55 PM  
Solid-state Additive Manufacturing of AA6061-graphene MMCs: Jessica Lopez1; Malcom Williams1; James Jordon1; Timothy Rushing2; Gregory Thompson1; Paul Allison1; 1The University of Alabama; 2U.S. Army ERDC
    Aluminum Alloy 6061 and graphene metal matrix composites were produced using additive friction stir deposition (AFS-D), a solid-state additive manufacturing process. The graphene particles (GPs) were distributed into the aluminum matrix while simultaneously being additively deposited in the solid state in compositions between 0.25 and 2 wt.%. The depositions were characterized with X-ray diffraction, optical and electron microscopy, and Raman spectroscopy techniques. The GPs were distributed within grains and the GPs reduced in size from several microns to less than 0.2 Ám wide through this solid-state process. Differences in particle dispersion between the retreating and advancing sides of tool rotation were quantified in the deposition. Raman spectroscopy confirmed the graphitic nature of the GPs in the matrix after deposition, which showed an increase their disorder. The dependence of the resulting hardness of the deposit on the graphene content, dispersion degree, and location was quantified using Vickers microhardness measurements.

3:15 PM  Invited
NOW ON-DEMAND ONLY - Development of Aluminum-based Metal Matrix Composites Using Friction Extrusion: Rajib Kalsar1; Xiaolong Ma1; Jens Darsell1; Miao Song1; Nicole Overman1; Keerti Kappagantula1; Vineet Joshi1; 1Pacific Northwest National Laboratory
    Friction extrusion process is a newly developed solid-state processing method and emerging as a potential processing method of microstructural modification to improve mechanical properties. Friction extrusion process has been utilized to generate metal matrix composite (MMC) microstructures in Al alloys to achieve better strength and ductility simultaneously. Ceramic powders (Al2O3 and MgO) with 5, 10 and 15 vol% were used to get Al MMC microstructures. Composites were extruded in the form of 5 mm diameter rod. Quantitative microstructural characterization was performed using scanning electron microscopy (SEM), back-scatter electron microscopy (EBSD) and transmission electron microscopy (TEM) to understand the distribution of the ceramic particles in Al matrix in the extruded rods. Mechanical properties of MMCs were evaluated by performing compression and tensile tests of the extruded rods.

3:40 PM Break

3:55 PM  
An Investigation of Mechanical Properties of Additively Manufactured Regolith Reinforced Titanium Alloy [Ti6Al4V]: Ali Afrouzian1; Kellen Traxel1; Amit Bandyopadhyay1; 1Washington State University
    Developing human habitation on extraterrestrial sites such as Moon and Mars has been scientists' dream for many years. Establishing such an outpost requires the development of in situ fabrication and characterization of various constructions and resources for reliable performance and developing repair methods and continued operation of components sent to the surface. The surface of Mars is covered with heterogeneous soil-like rock termed regolith. The processability of this regolith into a strong yet stable structure needs to be addressed. To this end, additive manufacturing (AM) is considered a promising approach to making such structures with improved properties. In this study, we have utilized the directed energy deposition (DED) technique to fabricate premixed Martian Regolith (MR) and Ti6Al4V (Ti64). AM processed samples were tested for hardness and microstructures to understand the processing-structure-property relationship. While the hardness profile shows an increase from 171.5 ▒ 1.5 MPa in the substrate to 924.7 ▒ 38 MPa in the pure deposition of Martian regolith, the microstructure reveals there are different crack and void zones in the 10 wt% addition of Martian rock to the Ti64 base powder. Our results show promise for developing hard coating fabrication technologies on the Martian surface.

4:15 PM  Cancelled
In-situ Synthesis of (TiB+TiN)/Ti Composites with Ultrahigh Mechanical Strength via Laser Powder Bed Fusion: Boyuan Li1; Changjun Han1; Kun Zhou1; 1Nanyang Technological University
    Titanium matrix composites reinforced by titanium boride (TiB) and titanium nitride (TiN) were in-situ synthesized using titanium and boron nitride (BN) powders via laser powder bed fusion (LPBF). Ultrahigh mechanical strength was achieved in the composite with 0.5 wt% of BN. A high content of BN could be favorable to composite strengthening but deteriorated the printability. An optimal content of 0.5 wt% was determined for BN, and near-full-dense samples were printed. Nano-sized precipitates of TiB and TiN were embedded in the α-Ti matrix. The ultimate tensile strength of the composite was enhanced by ~85% from ~590 MPa to ~1100 MPa, whereas the elongation was reduced to ~3%. The flat fracture surface of the composite consisted of quasi-cleavage steps indicating a brittle-fracture mode. This study provided insights into the reinforcement selection for additively manufactured composites with near-full density and strengthened mechanical performance.