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Full-Text Articles in Engineering
The Effect Of Parameters In Cryogenic Treatment On Mechanical Properties Of Tool Steel: A Review, Ronaldus Caesariano Ekaputra, Myrna Ariati Mochtar
The Effect Of Parameters In Cryogenic Treatment On Mechanical Properties Of Tool Steel: A Review, Ronaldus Caesariano Ekaputra, Myrna Ariati Mochtar
Journal of Materials Exploration and Findings
Tool steel is classified as special alloy steel which proposed as dies or mold materials as their high mechanical properties and dimensional stability. In order to improve tool steel’s mechanical properties, heat treatment process, especially, cryogenic treatment is conducted. Cryogenic treatment is done by exposing tool steel material at sub-zero liquid/gas media after heated at austenite temperature. This process significantly affects the martensite phase transformation increase and avoids retained austenite emersion. In particular, the higher martensite volume fraction, the higher hardness and wear resistance value of tool steel. It had been proven that adjusting critical process parameters of cryogenic treatment …
Synergistic Strategies In Sinter-Based Material Extrusion (Mex) 3d Printing Of Copper: Process Development, Product Design, Predictive Maps And Models., Kameswara Pavan Kumar Ajjarapu
Synergistic Strategies In Sinter-Based Material Extrusion (Mex) 3d Printing Of Copper: Process Development, Product Design, Predictive Maps And Models., Kameswara Pavan Kumar Ajjarapu
Electronic Theses and Dissertations
3D printing pure copper with high electrical conductivity and exceptional density has long been challenging. While laser-based additive manufacturing technologies suffered due to copper's highly reflective nature towards laser beams, parts printed via binder-assisted technologies failed to reach over 90% IACS (International Annealed Copper Standard), electrical conductivity. Although promising techniques such as binder jetting, filament, and pellet-based 3D printing that can print copper exist, they however still face difficulties in achieving both high sintered densities and electrical conductivity values. This is due to a lack of comprehensive understanding of property evolution from green to sintered states and the strategies that …
Mechanism Underlying Effect Of Expansive Agent And Shrinkage Reducing Admixture On Mechanical Properties And Fiber-Matrix Bonding Of Fiber-Reinforced Mortar, Kamran Aghaee, Taihao Han, Aditya Kumar, Kamal Khayat
Mechanism Underlying Effect Of Expansive Agent And Shrinkage Reducing Admixture On Mechanical Properties And Fiber-Matrix Bonding Of Fiber-Reinforced Mortar, Kamran Aghaee, Taihao Han, Aditya Kumar, Kamal Khayat
Materials Science and Engineering Faculty Research & Creative Works
Expansive agent (EA) and shrinkage reducing admixture (SRA) are utilized to reduce shrinkage and risk of cracking in concrete. EA compensates shrinkage by initial expansion, and SRA reduces surface tension in the pore fluid. Although EA and SRA effectively reduce shrinkage, they can impair micro-structure of concrete at high contents. The shrinkage reduction effect of EA and SRA is well known; however, there is limited knowledge about their negative effect on microstructure and fiber matrix interfacial transition zone (ITZ). The current study explores the effect of using 10 % CaO-based EA, 2 % SRA, and their combination on mechanical, shrinkage, …
Investigation Of Deformation Behavior Of Additively Manufactured Aisi 316l Stainless Steel With In Situ Micro-Compression Testing, Fei Teng, Ching-Heng Shiau, Cheng Sun, Robert C. O'Brien, Michael D. Mcmurtrey
Investigation Of Deformation Behavior Of Additively Manufactured Aisi 316l Stainless Steel With In Situ Micro-Compression Testing, Fei Teng, Ching-Heng Shiau, Cheng Sun, Robert C. O'Brien, Michael D. Mcmurtrey
Materials Science and Engineering Faculty Publications and Presentations
Additive manufacturing techniques are being used more and more to perform the precise fabrication of engineering components with complex geometries. The heterogeneity of additively manufactured microstructures deteriorates the mechanical integrity of products. In this paper, we printed AISI 316L stainless steel using the additive manufacturing technique of laser metal deposition. Both single-phase and dual-phase substructures were formed in the grain interiors. Electron backscatter diffraction and energy-dispersive X-ray spectroscopy indicate that Si, Mo, S, Cr were enriched, while Fe was depleted along the substructure boundaries. In situ micro-compression testing was performed at room temperature along the [001] orientation. The dual-phase substructures …
Optimization Of Porosity In Cold Spray Produced Copper And Zinc Coatings, Cameron Hughes
Optimization Of Porosity In Cold Spray Produced Copper And Zinc Coatings, Cameron Hughes
Graduate Theses & Non-Theses
Since its invention in 1981, the cold spray (CS) additive manufacturing (AM) process has been studied and optimized to produce well-adhered, dense material coatings. CS can operate at a wide range of temperatures if the feed material remains in a solid state. Copper and zinc were studied to characterize and understand the effects of heating element voltage, travel speed, and standoff distance on deposit porosity, grain size, microhardness, and coating thickness. Samples were sprayed on 3.2 mm x 25 mm x 150 mm 6061 aluminum substrates. Sections were taken from the middle of the samples to represent steady-state conditions. Sample …
A High-Strength Precipitation Hardened Cobalt-Free High-Entropy Alloy, Matthew Luebbe, Jiaqi Duan, Fan Zhang, Jonathan Poplawsky, Hans Pommeranke, Maalavan Arivu, Andrew Hoffman, Mario F. Buchely, Haiming Wen
A High-Strength Precipitation Hardened Cobalt-Free High-Entropy Alloy, Matthew Luebbe, Jiaqi Duan, Fan Zhang, Jonathan Poplawsky, Hans Pommeranke, Maalavan Arivu, Andrew Hoffman, Mario F. Buchely, Haiming Wen
Materials Science and Engineering Faculty Research & Creative Works
Recent Studies on Precipitation-Hardened High-Entropy Alloys (HEAs) Demonstrate their High Strength and Thermal Stability, Making Them Promising Materials for High-Temperature Structural Applications Such as Nuclear Reactors. However, Many Existing HEAs Contain Cobalt (Co), Which is Unsuitable for Nuclear Applications Because of the Long-Term Activation Issue of Co. Co is Also Expensive and Considered a Critical Material for Other Applications. Therefore, It is Desired to Exclude Co from the Composition. a Co-Free (Fe0.3Ni0.3Mn0.3Cr0.1)88Ti4Al8 HEA Was Developed and Studied in This Work. in Contrast to Previous Co-Free HEAs, This Alloy is …
Physics-Based Crystal Plasticity Model For Predicting Microstructure Evolution And Dislocation Densities, Juyoung Jeong
Physics-Based Crystal Plasticity Model For Predicting Microstructure Evolution And Dislocation Densities, Juyoung Jeong
LSU Doctoral Dissertations
This work presents three different studies investigating plastic deformation mechanisms in metals and alloys using crystal plasticity finite element (CPFE) modeling. The first study presents a new nonlocal crystal plasticity model for face-centered cubic single crystals under heterogeneous inelastic deformation. The model incorporates generalized constitutive relations that incorporate the thermally activated and drag mechanisms to cover different kinetics of viscoplastic flow in metals and describes the plastic flow and yielding of single-crystals using dislocation densities. The model is compared to micropillar compression experiments for copper single crystals and clarifies the complex microstructural evolution of dislocation densities in metals. The second …
Synthesizing Ti–Ni Alloy Composite Coating On Ti–6al–4v Surface From Laser Surface Modification, Yitao Chen, Joseph William Newkirk, Frank W. Liou
Synthesizing Ti–Ni Alloy Composite Coating On Ti–6al–4v Surface From Laser Surface Modification, Yitao Chen, Joseph William Newkirk, Frank W. Liou
Materials Science and Engineering Faculty Research & Creative Works
In This Work, a Ni-Alloy Deloro-22 Was Laser-Deposited on a Ti–6Al–4V Bar Substrate with Multiple Sets of Laser Processing Parameters. the Purpose Was to Apply Laser Surface Modification to Synthesize Different Combinations of Ductile TiNi and Hard Ti2Ni Intermetallic Phases on the Surface of Ti–6Al–4V in Order to Obtain Adjustable Surface Properties. Scanning Electron Microscopy, Energy Dispersion Spectroscopy, and X-Ray Diffraction Were Applied to Reveal the Deposited Surface Microstructure and Phase. the Effect of Processing Parameters on the Resultant Compositions of TiNi and Ti2Ni Was Discussed. the Hardness of the Deposition Was Evaluated, and Comparisons with …
Boro/Carbothermal Reduction Co-Synthesis Of Dual-Phase High-Entropy Boride-Carbide Ceramics, Lun Feng, William Fahrenholtz, Gregory E. Hilmas, Stefano Curtarolo
Boro/Carbothermal Reduction Co-Synthesis Of Dual-Phase High-Entropy Boride-Carbide Ceramics, Lun Feng, William Fahrenholtz, Gregory E. Hilmas, Stefano Curtarolo
Materials Science and Engineering Faculty Research & Creative Works
Dense, dual-phase (Cr,Hf,Nb,Ta,Ti,Zr)B2-(Cr,Hf,Nb,Ta,Ti,Zr)C ceramics were synthesized by boro/carbothermal reduction of oxides and densified by spark plasma sintering. The high-entropy carbide content was about 14.5 wt%. Grain growth was suppressed by the pinning effect of the two-phase ceramic, which resulted in average grain sizes of 2.7 ± 1.3 µm for the high-entropy boride phase and 1.6 ± 0.7 µm for the high-entropy carbide phase. Vickers hardness values increased from 25.2 ± 1.1 GPa for an indentation load of 9.81 N to 38.9 ± 2.5 GPa for an indentation load of 0.49 N due to the indentation size effect. Boro/carbothermal …