Article
Nanoscience & Nanotechnology
Chengshang Zhou, Fangrui Lin, Pei Sun, Zoujun Chen, Zhongyuan Duan, Xianzhi Zhu, Yong Liu, Zhigang Zak Fang
Summary: This paper introduces a novel approach called constrained hydrogenation assisted densification (CHAD) for improving the density of powder metallurgy Ti alloys. The results demonstrate that CHAD can effectively reduce or eliminate residual porosity in Ti alloys and improve their tensile properties. This method is considered as an efficient and cost-effective technique for manufacturing high-density Ti alloys.
SCRIPTA MATERIALIA
(2022)
Article
Engineering, Industrial
Alexander D. Preston, Kaka Ma
Summary: Spark plasma sintering (SPS) is an efficient consolidation process for metals and ceramics. This study developed a strategy to incorporate the master sintering curve (MSC) into a thermal-electric finite element modeling (FEM) to simulate the evolution of thermal and electrical properties during SPS. Experimental verification on pure Ti samples showed the accuracy of the MSC-TE FEM combined model in guiding the control and utilization of gradients in SPS to achieve graded microstructure.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Jinwoo Lee, Hyuk Jong Bong, Daeyong Kim, Jinjin Ha
Summary: In this study, the mechanical responses and ductile damage behavior of Ti-6Al-4V alloy sheets at high temperature were investigated through experiments and numerical simulations. The improvement in formability at high temperature was also evaluated.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Mathematics, Interdisciplinary Applications
V Ivannikov, F. Thomsen, T. Ebel, R. Willumeit-Roemer
Summary: A novel discrete element method-based approach is proposed for modeling solid state sintering of spherical metallic powder, addressing the thermodynamical mass transport effects and mechanical interaction between particles near grain boundaries. The model consists of solving partial differential equations to describe matter flow behavior at grain boundaries and representing the mechanical interaction using 2-nodal structural elements with 6 degrees of freedom per node. Numerical implementation shows good agreement with experimental data for neck growth and shrinkage rates.
COMPUTATIONAL PARTICLE MECHANICS
(2022)
Review
Engineering, Chemical
T. Chen, C. Suryanarayana, C. Yang
Summary: Advanced Ti materials, including Ti, Ti alloys, and Ti-matrix composites, have significant advantages over conventional counterparts in terms of higher performance, lower cost, and wider applications. Titanium hydride (TiH2) powder has many advantages in producing advanced Ti materials, such as high relative density, novel microstructure, and competitive mechanical properties. This review summarizes the research progress on the dehydrogenation mechanism and resultant effect of TiH2 powder, the interrelation between processing technologies, microstructures, and mechanical properties of advanced Ti materials, and the influence of Kirkendall's pores on mechanical properties of Ti matrix composites.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
Sheng Huang, R. Lakshmi Narayan, Joel Heang Kuan Tan, Swee Leong Sing, Wai Yee Yeong
Summary: This study investigated the influence of laser power, velocity, and profile on the porosity, inclusion content, and microstructural evolution of in-situ alloyed laser powder bed fusion manufactured Ti34Nb. It found that a specific combination of laser profile, power, velocity, and scanning strategy could result in the formation of an ideal microstructure.
Article
Engineering, Chemical
Julia C. Bonaldo, Stephane Mazerat, Severine Romero-Baivier, Christophe L. Martin
Summary: This study describes an original methodology using the Discrete Element Method (DEM) to simulate the compaction behavior of refractories, taking into account the microstructure of each composite phase. The simulations provide insights into the densification behavior of composites with different compositions.
Article
Nanoscience & Nanotechnology
Levent Karacasulu, Ezgi Ogur, Cerem Piskin, Cekdar Vakifahmetoglu
Summary: The ordinary recycled soda lime glass powder was densified through cold sintering process with the aid of concentrated NaOH solution. Increasing processing time, temperature, and concentration of NaOH solution led to the formation of monolithic glass artifacts with higher relative densities. The highest densification (95.2%) was achieved when sintering was done at 250 degrees C for 20 minutes using 15 M NaOH solution.
SCRIPTA MATERIALIA
(2021)
Article
Automation & Control Systems
Alaa Olleak, Zhimin Xi
Summary: This paper investigates the thermomechanical modeling of the LPBF process, examining the effects of model assumptions using 2D models and proposing a framework to address the computational expense issue. The study demonstrates the importance of model assumptions and the effectiveness of the proposed framework through parts from different materials.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Engineering, Multidisciplinary
Pavana Prabhakar, Haotian Feng, Sabarinathan P. Subramaniyan, Mrityunjay Doddamani
Summary: In this paper, the densification mechanics of polymeric syntactic foams under compressive loading are investigated using computational models and regression analysis. It is found that microballoon crushing strength and volume fraction have the highest influence on densification stress and energy, while interfacial bonding has the least impact. In addition, the design aspects of syntactic foams with specific overall density are discussed by mapping microballoon volume fraction and wall thickness.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Engineering, Chemical
Dayong Yang, Yuchen Zhang, Rui Wang, Furui Wei, Lingxin Zeng, Min Liu
Summary: This study investigated the impact of different machining variables on cutting force in powder metallurgy green compacts using finite element simulation. The results showed that cutting thickness had a significant impact on cutting force, and rounded-edge radius and cutting speed were also important factors. The optimal process parameters for minimizing cutting force were identified as a cutting thickness of 0.20 mm, a cutting speed of 120 m/min, a tool rake angle of 0 degrees, and a rounded-edge radius of 40 μm, resulting in a cutting force of 887.95 N.
Article
Engineering, Civil
Ali Shiravand, Masoud Asgari
Summary: This paper investigates the elastic modulus and energy absorption behavior of cellular structures, such as aluminum foams, and develops a microstructure modeling of cellular structures. Through finite element method, the behavior of the unit cell and the foams under impact is simulated and analyzed. A model using the response surface method is presented to obtain the densification strain, elastic modulus, mean plastic stress, yield stress, and foam compaction behavior. The results show the possibility of modeling and analyzing the energy absorption of foams using the response surface model.
Article
Thermodynamics
Sungjoon Byun, Haijun Jeong, Dong Rip Kim, Kwan-Soo Lee
Summary: The study focused on the impact of frost and fog during the vaporization of liquefied natural gas, specifically examining their influence on ambient air vaporizers. Experimental results indicated that fog generation was primarily influenced by the frost surface temperature. Frost and fog modeling could be utilized for predicting the timing of fog formation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Materials Science, Multidisciplinary
E. T. Furton, A. M. Beese
Summary: This study investigates the effects of pores on the mechanical properties of metals produced by additive manufacturing, which can limit strength and ductility. The rate of crack growth emanating from these pores in additively manufactured Ti-6Al-4 V fabricated with laser powder bed fusion was measured and modeled. The results showed that crack growth occurred after necking in samples with small pores, while samples with large pores experienced continuous crack growth with strain.
EXPERIMENTAL MECHANICS
(2023)
Review
Materials Science, Multidisciplinary
Jaclyn L. Cann, Anthony De Luca, David C. Dunand, David Dye, Daniel B. Miracle, Hyun Seok Oh, Elsa A. Olivetti, Tresa M. Pollock, Warren J. Poole, Rui Yang, C. Cem Tasan
Summary: Exciting metallurgical breakthroughs in recent decades have ushered in a new era in metals design, with the urgent need for new metallic materials to address current engineering challenges. While the environmental impact of the metallurgical industry is significant, the design of new metallic materials with improved properties can help tackle key environmental challenges.
PROGRESS IN MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Muath M. Al Malki, Xun Shi, Pengfei Qiu, G. Jeffrey Snyder, David C. Dunand
Summary: The n-type Skutterudite alloy Yb0.3Co4Sb12 exhibits plastic deformation and creep characteristics under compressive stress at 500 degrees C, showing a moderate creep resistance. The study results indicate that Yb0.3Co4Sb12 can withstand certain pressures and maintain ductility at 500 degrees C, but a decrease in electrical conductivity leads to a slight reduction in its thermoelectric performance.
JOURNAL OF MATERIOMICS
(2021)
Article
Engineering, Manufacturing
C. Kenel, N. R. Geisendorfer, R. N. Shah, D. C. Dunand
Summary: The study focuses on the creation of hierarchically porous Fe or Ni scaffolds using 3D ink-extrusion of powders followed by sintering. The resulting metallic lattices exhibit hierarchical porosities with different pore sizes, which can be controlled by adjusting the sintering temperature and time.
ADDITIVE MANUFACTURING
(2021)
Article
Nanoscience & Nanotechnology
Shipeng Shu, Anthony De Luca, David C. Dunand, David N. Seidman
Summary: The addition of a small amount of slow-diffusing W to the alloy accelerates one type of precipitation but hinders another, leading to an increase in peak-microhardness during aging without improving coarsening and creep resistance.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Shipeng Shu, Anthony De Luca, David C. Dunand, David N. Seidman
Summary: Micro-additions of 0.25 at.% Mn and/or 0.10 at.% Mo to dilute Al-0.08Zr-0.014Sc-0.008Er-0.09Si alloys affect precipitate evolution and resulting strengths, providing solid-solution strengthening and improving ambient-temperature strength and elevated-temperature creep resistance. Mn-modified precipitates exhibit higher number density, while Mo-modified precipitates display improved coarsening-resistance. Both Mn and Mo additions enhance creep resistance at 300 degrees C, with Mn-bearing alloys showing a more significant effect.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Anthony De Luca, Christoph Kenel, Seth Griffiths, Shreyas S. Joglekar, Christian Leinenbach, David C. Dunand
Summary: Additive manufacturing of non-weldable high-gamma' Ni base superalloys faces challenges due to their inherent cracking propensity. The segregation of melting point-depressant elements to grain boundaries drastically increases the solidification interval and leads to solid-state cracking at high-angle GBs. The study found that Ti, Cr, and Al segregate to solidification cell boundaries, while the formation of oxide and sulfide precipitates influences the alloy performance.
MATERIALS & DESIGN
(2021)
Article
Nanoscience & Nanotechnology
Liyang Wang, Bing Ye, Yang Bai, Beibei Zhao, Wenjiang Ding
Summary: Micro-additions of Zr and Sc, as well as combined addition, are effective in improving the strength and grain characteristics of Al-Ce alloys through gravity casting. The formation of nanoscale precipitates after heat treatment contributes to enhancing the alloy performance significantly.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Liyang Wang, Hongquan Song, Bing Ye, Beibei Zhao, Yang Bai, Wenjiang Ding
Summary: The Al-8Ce-3Y high pressure die-casting alloy exhibits excellent mechanical properties at high temperatures, attributed to the formation of stable Al-4(Ce,Y) phase with the addition of Y.
Article
Nanoscience & Nanotechnology
Tiffany Wu, A. Plotkowski, A. Shyam, David C. Dunand
Summary: This study investigates the microstructures, thermal stability, ambient temperature strengthening, and creep resistance of three ternary Al-Ce-Ni alloys. The results show that the high volume fraction of intermetallic phases and extremely fine eutectic spacing/fiber diameter contribute to high ambient strengthening and enhanced creep resistance. The alloys also exhibit coarsening resistance up to 425 degrees C and remain substantial creep resistance at 300 degrees C, making them excellent materials for high temperature applications.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Daniel F. T. Rosenthal, David C. Dunand
Summary: Finite element modeling is utilized to simulate the secondary creep rate of alloys with inhomogeneous distribution of nano-precipitates within dendritic microstructures. The geometry and loading direction of dendrites have a significant impact on the alloy's creep behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Manufacturing
Christoph Kenel, Anthony De Luca, Shreyas S. Joglekar, Christian Leinenbach, David C. Dunand
Summary: The study focuses on the successful synthesis of oxide-dispersion-strengthened alloys using laser powder bed fusion, emphasizing the interaction between oxide dispersoids and the metallic melt pool. By analyzing the behavior of Y2O3 nanoparticles in a Ni-8Cr-5.5Al-1Ti alloy, the critical role of Al in reacting with oxide nanodispersoids during the manufacturing process is discussed, along with suggestions for potentially more successful dispersoids types.
ADDITIVE MANUFACTURING
(2021)
Article
Nanoscience & Nanotechnology
Yang Bai, Xin Yu, Liyang Wang, Nan Zhang, Bing Ye, Weili Cheng, Xiangyang Kong
Summary: A new high pressure die-casting (HPDC) Mg-RE based alloy with excellent heat resistance has been successfully prepared. It exhibits high tensile strength and low creep rate, which can be attributed to the fine-grained structure, co-segregation of Y and Zn atoms, and coherent LPSO phase with networking distribution. This newly developed alloy shows promising prospects for automotive powertrain components.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Beibei Zhao, Jiaying Zhang, Bing Ye, Liyang Wang, Yang Bai, Xin Yu
Summary: The microstructure, mechanical properties, and thermal stability of a high-pressure die casting (HPDC) Al-12Si-Sc alloy with 0.1 wt% Sc addition are investigated. Compared to the commercial A380 alloy, the alloy exhibits a significant refinement in the microstructure of alpha-Al and eutectic Si. Additionally, the beta-Fe phase in the Al-12Si-Sc alloy shows smaller size and lower volume fraction. The alloy demonstrates improved ductility and strength, with an elongation of 6.7% and an ultimate tensile strength of 332 MPa in the as-cast state.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Beibei Zhao, Bing Ye, Liyang Wang, Yang Bai, Xin Yu, Qigui Wang, Wenying Yang
Summary: The mechanical behavior and microstructure evolution of a newly developed high strength die casting Al-13Si0.25Cu alloy were investigated in different conditions, showing that ageing treatment can improve the yield strength while thermal exposure can result in reduced hardness and increased ductility.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Liyang Wang, Bing Ye, Wei Huang, Wenjiang Ding
Summary: Despite the wide range of applications and studies on eutectic alloys, there is currently no available model to describe the contribution of morphology on the strength of the eutectic structure. Researchers have derived a eutectic strengthening model, based on the Brown model and Taylor-Orowan's equation, which can effectively predict the yield strength of eutectic alloys and provide insights into eutectic strengthening. The model reveals the relationship between yield strength and eutectic features such as slip parameter, effective shear modulus, second phase volume fraction, and eutectic spacing, and its predictions are in good agreement with experimental measurements for different eutectic alloys.
SCRIPTA MATERIALIA
(2023)
