scholarly journals Ultrasonic Surface Rolling Process: Properties, Characterization, and Applications

2021 ◽  
Vol 11 (22) ◽  
pp. 10986
Author(s):  
Merbin John ◽  
Alessandro M. Ralls ◽  
Scott C. Dooley ◽  
Akhil Kishore Vellooridathil Thazhathidathil ◽  
Ashok Kumar Perka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rolling Process ◽  
Deep Rolling ◽  
Fatigue Wear ◽  
Comprehensive Overview ◽  
Current State ◽  
Tensile Fatigue ◽  
Gradient Microstructure ◽  
Stress Corrosion Resistance ◽  
Superior Mechanical Properties

Ultrasonic surface rolling process (USRP) is a novel surface severe plastic deformation (SPD) method that integrates ultrasonic impact peening (UIP) and deep rolling (DR) to enhance the surface integrity and surface mechanical properties of engineering materials. USRP can induce gradient nanostructured surface (GNS) layers on the substrate, providing superior mechanical properties, thus preventing premature material failure. Herein, a comprehensive overview of current-state-of-the art USRP is provided. More specifically, the effect of the USRP on a broad range of materials exclusively used for aerospace, automotive, nuclear, and chemical industries is explained. Furthermore, the effect of USRP on different mechanical properties, such as hardness, tensile, fatigue, wear resistance, residual stress, corrosion resistance, and surface roughness are summarized. In addition, the effect of USRP on grain refinement and the formation of gradient microstructure is discussed. Finally, this study elucidates the application and recent advances of the USRP process.

Correlation between Microstructure and Properties of Semi-Solid Products

2019 ◽  
Vol 285 ◽  
pp. 12-23 ◽  
Author(s):  
Annalisa Pola
Keyword(s):  
Mechanical Properties ◽  
Fatigue Wear ◽  
Microstructure And Properties ◽  
Tensile Fatigue ◽  
Wear And Corrosion ◽  
Semi Solid ◽  
Wear And Corrosion Resistance ◽  
Permanent Mold Castings ◽  
The Relationship ◽  
Better Than

Since the very first production trials, it was evident that semi-solid components exhibit excellent mechanical properties, comparable to those of forged material and, in any case, better than permanent mold castings. Over the years, these findings have been confirmed by many authors. Most of the papers available in scientific literature deals with the demonstration of this improvement, especially in order to show the reliability of new and alternative production routes. On the contrary, only some studies focus their attention on the relationship between enhanced mechanical properties and the microstructure. However, it is demonstrated that the increased performance of semi-solid components is not only due to the absence of porosity, but there is a clear relationship between microstructure and properties. This paper reports about the state of knowledge in this subject, in particular for what concerns tensile, fatigue, wear and corrosion resistance.

Sintered Metal Microstructure Influenced by Deep Rolling and Carburizing Processes

2017 ◽  
Vol 751 ◽  
pp. 96-100
Author(s):  
Sai Yan Primee
Keyword(s):  
Mechanical Properties ◽  
Surface Properties ◽  
Outer Surface ◽  
Surface Hardness ◽  
Rolling Process ◽  
Applied Force ◽  
Deep Rolling ◽  
Chemical Surface ◽  
Sintered Metal ◽  
Metal Microstructure

For better mechanical properties and lifetime of sintered products, it is suggested that an improvement can be made by a combination of mechanical-and chemical-surface treatments. In this study, the effect of deep-rolling on surface properties and microstructure is investigated. It is found that both compactness and hardness is improved by deep-rolling process where high force is applied. The outer surface hardness can be doubled when the deep-rolling is applied prior to carburizing. Nonetheless, a reduction in the thickness of the martensite-transformed layer due to an increment of applied force is observed.

scholarly journals Nanocrystalline Materials: Synthesis, Characterization, Properties, and Applications

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1317
Author(s):  
Amanendra K. Kushwaha ◽  
Merbin John ◽  
Manoranjan Misra ◽  
Pradeep L. Menezes
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Chemical Vapor ◽  
Chemical Precipitation ◽  
High Energy ◽  
Synthesis Methods ◽  
Materials Synthesis ◽  
Current State ◽  
Superior Mechanical Properties ◽  
Energy Ball

Nanostructuring is a commonly employed method of obtaining superior mechanical properties in metals and alloys. Compared to conventional polycrystalline counterparts, nanostructuring can provide remarkable improvements in yield strength, toughness, fatigue life, corrosion resistance, and hardness, which is attributed to the nano grain size. In this review paper, the current state-of-the-art of synthesis methods of nanocrystalline (NC) materials such as rapid solidification, chemical precipitation, chemical vapor deposition, and mechanical alloying, including high-energy ball milling (HEBM) and cryomilling was elucidated. More specifically, the effect of various process parameters on mechanical properties and microstructural features were explained for a broad range of engineering materials. This study also explains the mechanism of grain strengthening using the Hall-Petch relation and illustrates the effects of post-processing on the grain size and subsequently their properties. This review also reports the applications, challenges, and future scope for the NC materials.

Micromechanical Characterization of Multilayered Steel Composites

2011 ◽  
Vol 1296 ◽  
Author(s):  
K. Hirashita ◽  
M. Matsuda ◽  
M. Otsu ◽  
K. Takashima
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Deformation Behavior ◽  
Treatment Time ◽  
Rolling Process ◽  
Microtensile Testing ◽  
Heat Treated ◽  
Superior Mechanical Properties ◽  
Micromechanical Characterization

ABSTRACTThe mechanical properties and deformation behavior of each constituent layer of multilayered steel composites were examined using microtensile testing. Three-layered integrated steels consisting of SUS420 and SPCC (cold-reduced carbon steel sheets) were fabricated by a cold-rolling process. Different heat treatment processes were used to prepare three types of specimens (as-rolled, 823K-2 min heat-treated, and 823K-500 min heat-treated), and the effect of heat treatment on their mechanical properties was investigated. In the as-rolled specimens, the average tensile strengths in the SUS420 and SPCC layers were 1063 and 606 MPa, respectively, while in the specimens heat-treated for 500 min, they were 680 and 451 MPa, respectively. The tensile strength decreased with the increase in the heat treatment time. The tensile strength of the specimens was also calculated by using the rule of mixture. For the as-rolled specimens and the 823K-2 min heat-treated specimens, the calculated value was consistent with the measured value; however, for the 823K-500 min heat-treated specimens, the calculated value was lower than the measured value. This result suggests that the necking of this layered structure was effectively obstructed by the outer ductile layer. The micromechanical characterization technique used in this study is useful not only for investigating deformation behavior but also for designing multilayered steel composites with superior mechanical properties.

scholarly journals Peening Techniques for Surface Modification: Processes, Properties and Applications

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3841
Author(s):  
Merbin John ◽  
Prasad Rao Kalvala ◽  
Manoranjan Misra ◽  
Pradeep L. Menezes
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Review Paper ◽  
State Of The Art ◽  
Metals And Alloys ◽  
Laser Shock ◽  
Current State ◽  
Potential Applications ◽  
Superior Mechanical Properties ◽  
Shock Peening

Surface modification methods have been applied to metals and alloys to change the surface integrity, obtain superior mechanical properties, and improve service life irrespective of the field of application. In this review paper, current state-of-the-art of peening techniques are demonstrated. More specifically, classical and advanced shot peening (SP), ultrasonic impact peening (UIP), and laser shock peening (LSP) have been discussed. The effect of these techniques on mechanical properties, such as hardness, wear resistance, fatigue life, surface roughness, and corrosion resistance of various metals and alloys, are discussed. This study also reports the comparisons, advantages, challenges, and potential applications of these processes.

Metallic Nanoneedles Arrays for TEM Sample Preparation “Lift-Out”

2012 ◽  
Author(s):  
Romaneh Jalilian ◽  
David Mudd ◽  
Neil Torrez ◽  
Jose Rivera ◽  
Mehdi M. Yazdanpanah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Sample Preparation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam System ◽  
Transmission Electron ◽  
Nanoneedle Array ◽  
Superior Mechanical Properties ◽  
And Performance

Abstract The sample preparation for transmission electron microscope can be done using a method known as "lift-out". This paper demonstrates a method of using a silver-gallium nanoneedle array for a quicker sharpening process of tungsten probes with better sample viewing, covering the fabrication steps and performance of needle-tipped probes for lift-out process. First, an array of high aspect ratio silver-gallium nanoneedles was fabricated and coated to improve their conductivity and strength. Then, the nanoneedles were welded to a regular tungsten probe in the focused ion beam system at the desired angle, and used as a sharp probe for lift-out. The paper demonstrates the superior mechanical properties of crystalline silver-gallium metallic nanoneedles. Finally, a weldless lift-out process is described whereby a nano-fork gripper was fabricated by attaching two nanoneedles to a tungsten probe.

scholarly journals Augmented Reality in Orthopedic Surgery Is Emerging from Proof of Concept Towards Clinical Studies: a Literature Review Explaining the Technology and Current State of the Art

2021 ◽  
Author(s):  
Fabio A. Casari ◽  
Nassir Navab ◽  
Laura A. Hruby ◽  
Philipp Kriechling ◽  
Ricardo Nakamura ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Orthopedic Surgery ◽  
Relevant Literature ◽  
Comprehensive Overview ◽  
Basic Principles ◽  
Clinical Procedures ◽  
Current State ◽  
Tremendous Progress ◽  
Orthopedic Oncology ◽  
Technological Developments

Abstract Purpose of Review Augmented reality (AR) is becoming increasingly popular in modern-day medicine. Computer-driven tools are progressively integrated into clinical and surgical procedures. The purpose of this review was to provide a comprehensive overview of the current technology and its challenges based on recent literature mainly focusing on clinical, cadaver, and innovative sawbone studies in the field of orthopedic surgery. The most relevant literature was selected according to clinical and innovational relevance and is summarized. Recent Findings Augmented reality applications in orthopedic surgery are increasingly reported. In this review, we summarize basic principles of AR including data preparation, visualization, and registration/tracking and present recently published clinical applications in the area of spine, osteotomies, arthroplasty, trauma, and orthopedic oncology. Higher accuracy in surgical execution, reduction of radiation exposure, and decreased surgery time are major findings presented in the literature. Summary In light of the tremendous progress of technological developments in modern-day medicine and emerging numbers of research groups working on the implementation of AR in routine clinical procedures, we expect the AR technology soon to be implemented as standard devices in orthopedic surgery.

scholarly journals Depression following traumatic brain injury: a comprehensive overview

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Marc Fakhoury ◽  
Zaynab Shakkour ◽  
Firas Kobeissy ◽  
Nada Lawand
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Health Concern ◽  
First Year ◽  
Comprehensive Overview ◽  
Symptoms Of Depression ◽  
Current State ◽  
Post Traumatic ◽  
Brain Changes

Abstract Traumatic brain injury (TBI) represents a major health concern affecting the neuropsychological health; TBI is accompanied by drastic long-term adverse complications that can influence many aspects of the life of affected individuals. A substantial number of studies have shown that mood disorders, particularly depression, are the most frequent complications encountered in individuals with TBI. Post-traumatic depression (P-TD) is present in approximately 30% of individuals with TBI, with the majority of individuals experiencing symptoms of depression during the first year following head injury. To date, the mechanisms of P-TD are far from being fully understood, and effective treatments that completely halt this condition are still lacking. The aim of this review is to outline the current state of knowledge on the prevalence and risk factors of P-TD, to discuss the accompanying brain changes at the anatomical, molecular and functional levels, and to discuss current approaches used for the treatment of P-TD.

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