About

Our nationally recognized faculty, researchers and professional staff are dedicated to excellence in research, education, innovation and service. Learn more about the individuals who make up the Department of Mechanical Engineering by visiting their profiles.

Research topics

• Metallurgy
• Materials science
• Composite material
• Condensed matter physics
• Thermodynamics
• Physics
• Geometry
• Mathematics
• Optics
• Crystallography

Selected publications

• Uncertainty-Guided Bandwidth-Adaptive Model Compression for Industrial Pore Detection

  2026-02-16

  article
  PublisherDOI

• Graphite-free fabrication of fully dense crack-free AA7075 aluminum alloy using additive friction stir deposition

  Progress in Additive Manufacturing · 2026-02-03 · 1 citations

  articleOpen accessSenior authorCorresponding

  Abstract Additive Friction-Stir Deposition is a form of solid-state additive manufacturing that has shown potential for producing large-scale components. Often, AFSD utilized a graphite lubricant during the manufacture of components from 7xxx-series aluminum alloys. In this work, AFSD was utilized without lubricant to print high-strength AA7075 aluminum alloy, which will reduce the risk of contamination to the feed material, ensuring that the deposited material retains mechanical properties akin to wrought or forged AA7075 aluminum alloy. The fabricated material underwent mechanical testing and characterization to better understand the mechanical properties and microstructure associated with AFSD-printed AA7075 alloy when graphite is removed. Optical imagery showed that the as-deposited material exhibited a fully dense and crack-free build. The microstructure was found to be heavily refined and equiaxed, which is consistent with most AFSD results, although different grain orientations were observed in each plane. The mechanical properties of the as-deposited material were not homogeneous, and mechanical properties were found to vary with height. T6 heat treatment resulted in significant grain growth, along with grain elongation. Remarkably, the heat treatment significantly minimized the anisotropic mechanical properties of the samples, enhancing them to reach 95% of the performance typically seen in wrought AA7075-T6 alloy, with yield strength and ultimate tensile strength averaging 480 MPa and 533 MPa respectively, and elongation averaging 9%. Post heat treatment, hardness also exhibited a significant increase, even for thicker samples, with average values of at least 169.9 HV.

  PublisherOA PDFDOI

• A comprehensive in-situ monitoring framework for pore and uneven surface detection in electron beam powder bed fusion via electron-optical imaging

  Journal of Manufacturing Processes · 2025-11-29 · 1 citations

  articleSenior authorCorresponding
  PublisherDOI

• Evaluation of the corrosion behavior of laser powder bed fusion (L-PBF) stainless steel 316 L in a simulated synovial fluid under inflammatory conditions

  Materialia · 2025-07-26 · 1 citations

  article
  PublisherDOI

• Deformation mechanisms of multiphase microstructures in laser powder bed fusion processed stainless steels

  Materials Science and Engineering A · 2025-03-17 · 4 citations

  articleOpen access
  PublisherOA PDFDOI

• Microstructural and Hall–Petch Analysis of Additively Manufactured Ferritic Alloy Using 2507 Duplex Stainless Steel Powder

  Crystals · 2024-01-15 · 10 citations

  articleOpen accessCorresponding

  The powder bed fusion–laser beam (PBF-LB) process, a method of additive manufacturing (AM), was used to print duplex stainless steel (DSS) using commercial-grade 2507 powders. While conventionally processed DSS has a two-phase microstructure consisting of 50% austenite and 50% ferrite, the PBF-LB-printed 2507 alloy was nearly 100% ferrite. Optimal processing conditions that minimized porosity were determined to be 290 W laser power and 1000 mm/s scan speed, and grain size, texture, and phases were characterized as a function of laser power and scan speed. Grain size increased with increasing laser power but decreased with increasing scan speed. A <100> texture diminished with increasing scan speed from 1000 mm/s to 1400 mm/s. No austenite phase was detected. Transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) characterization revealed nanoscale chromium nitride precipitates in the ferritic matrix (incoherent hexagonal close-packed (HCP) precipitates at grain boundaries and coherent body-centered cubic (BCC) precipitates within the grains) and a high density of tangled dislocations. Tensile tests of as-printed alloys showed a yield strength of 570 MPa, an ultimate tensile strength of 756 MPa, and an elongation to failure of 10%. The tensile properties were analyzed based on the observed microstructure considering grain size, nanoscale precipitates, and the high density of dislocations.

  PublisherOA PDFDOI

• Processing-microstructure relationships in ferrous alloys via mixed powder laser powder bed fusion

  Journal of Materials Research and Technology · 2024-04-26 · 1 citations

  articleOpen access

  Three different approaches to control the phase formation in powder bed fusion - laser beam (PBF-LB) printing using a powder mixture of duplex stainless steel (DSS) 2507 and austenitic stainless steel 316 L were examined: (i) in situ solid state reheating, (ii) utilization of an island scan strategy, and (iii) switching process parameters between layers of a build. Analytical modeling was used to determine the time-temperature profiles during each of these processes, and was combined with thermodynamic simulations through Thermo-Calc to predict and explain the phase formation measured experimentally. It was found that the reheating from additional layers was critical to the nucleation of austenite, even with the increased Ni content in powder mixtures. This was evident in the island scan strategy prints where the corners of the islands showed significantly less austenite (∼45%) as compared to the centers of the islands (∼96%), as well as in the multi-layer samples where alternating laser power for fixed chemical composition of powder mixture resulted in varying content from ∼75% (lower power) to ∼90% (higher power). Additionally, in situ reheating using a lower power laser was capable of minimally increasing the austenite content layer-by-layer, by raising the temperature of the layer above the nucleation temperature of austenite. These results showcase the capability of PBF-LB to manipulate phase structure in ways not possible through traditional manufacturing techniques, as well as the ability of Thermo-Calc to accurately predict the trends observed that can be applied to other alloy systems.

  PublisherDOI

• Quantification of grain boundary effects on the geometrically necessary dislocation density evolution and strain hardening of polycrystalline Mg 4Al using in situ tensile testing in scanning electron microscope and HR-EBSD

  Journal of Magnesium and Alloys · 2024-05-01 · 21 citations

  articleOpen access

  In situ tensile testing in a scanning electron microscope (SEM) in conjunction with high-resolution electron backscatter diffraction (HR-EBSD) under load was used to characterize the evolution of geometrically necessary dislocation (GND) densities at individual grain boundaries as a function of applied strain in a polycrystalline Mg4Al alloy. The increase in GND density was investigated at plastic strains of 0 %, 0.6 %, 2.2 %, 3.3 % from the area including 76 grains and correlated with (i) geometric compatibility between slip systems across grain boundaries, and (ii) plastic incompatibility. We develop expressions for the grain boundary GND density evolution as a function of plastic strain and plastic incompatibility, from which uniaxial tensile stress-strain response of polycrystalline Mg4Al are computed and compared with experimental measurement. The findings in this study contribute to understanding the mechanisms governing the strain hardening response of single-phase polycrystalline alloys and more reliable prediction of mechanical behaviors in diverse microstructures.

  PublisherDOI

• Mapping the roles of scan strategy and build orientation in predicting the crystallographic texture and yield strength of 316L stainless steel produced by laser powder bed fusion

  Journal of Materials Research and Technology · 2024-05-01 · 13 citations

  articleOpen access1st authorCorresponding

  Laser Powder Bed Fusion (L-PBF) has emerged as a leading additive manufacturing (AM) technique for manufacturing complex metal parts, with 316L stainless steel being favored for its exceptional corrosion resistance and mechanical properties. While previous studies have explored the effects of different scan strategies and build orientations on the microstructure and room temperature tensile properties of L-PBF printed 316L stainless steel, there is still a lack of a comprehensive predictive model that accurately captures the combined effects of these process parameters on the final crystallographic texture and tensile properties. This study presents a novel approach that establishes a direct correlation between process parameters, microstructure, and mechanical behavior by modeling the influence of scan strategy rotation angles and build orientations on the crystallographic texture of L-PBF-manufactured 316L stainless steel. To validate the model, a series of samples were fabricated using various scan strategy rotation angles and build orientations, enabling detailed microstructural analysis and mechanical testing. The findings demonstrate a direct relationship between the selected process parameters and the resulting mechanical properties, underscoring the importance of scan strategy and build orientation selection on mechanical response. Furthermore, our calibrated model exhibits high predictive accuracy as validated through a comparison with experimental data.

  PublisherDOI

• Crystallography and Interface Structures in As-Arc Melted and Laser Surface-Remelted Aluminum–Silicon Alloys with and without Strontium Addition

  Crystals · 2024-03-18 · 4 citations

  articleOpen access

  The crystallography of the eutectic Al-Si microstructure in both unmodified and Sr (0.2 wt.%)-modified hypereutectic Al-20 wt.% Si alloys, processed via arc-melting and laser surface remelting, has been comprehensively characterized using transmission electron microscopy and electron diffraction. Although, under as-cast conditions, specific orientations between different planes of Al and Si, satisfying defined orientation relationships (ORs), have been investigated within the flake morphology, the rapid solidification induced by laser surface remelting results in a notable transformation from a flake morphology to nanocrystalline Si fibers dispersed in an Al matrix. Consequently, this transformation results in a mis-orientation of the interface between the eutectic Al and Si phases, preventing the formation of orientation relationships, thus promoting the formation of faceted interfaces exhibiting substantial lattice disregistry.

  PublisherOA PDFDOI

Frequent coauthors

• Mohammad Elahinia

  University of Toledo

  33 shared

• Amit Misra

  University of Michigan–Ann Arbor

  20 shared

• Christoph Haberland

  16 shared

• H.E. Karaca

  University of Kentucky

  15 shared

• Mohammad Reza Karamooz-Ravari

  Graduate University of Advanced Technology

  13 shared

• Soheil Saedi

  13 shared

• Veera Sundararaghavan

  12 shared

• Jason Walker

  The Ohio State University

  11 shared

Awards & honors

• 2026 SME Outstanding Young Manufacturing Engineer Award
• 2022 Robert M. Caddell Memorial Award for Research, Universi…
• 2021 Richard and Eleanor Towner Prize for Outstanding Ph.D.…
• 2020 Ivor K. McIvor Award, University of Michigan
• 2018 Honorable Mention for SME’s 2018 class of 30 Under 30