scholarly journals Mechanical characterization of a new low carbon bainitic steel for high performance crankshaft

2018 ◽  
Vol 12 ◽  
pp. 438-447
Author(s):  
Paolo Citti ◽  
Alessandro Giorgetti ◽  
Ulisse Millefanti
Author(s):  
Paul Paret ◽  
Joshua Major ◽  
Douglas DeVoto ◽  
Sreekant Narumanchi ◽  
Yansong Tan ◽  
...  

Sintered silver-based bonded interfaces are a critical enabling technology for high-temperature, compact, high-performance, and reliable wide-bandgap packages and components. High-pressure (∼40 MPa) sintered silver interfaces have been implemented commercially, most notably the commercial products offered by Semikron. To reduce manufacturing complexity, there is significant industry interest in pressure-less sintered silver interfaces. To this end, current formulations of sintered silver paste are comprised of purely nano-sized silver particles or a combination of nano- and micro-sized silver particles/flakes. It is essential to quantify the mechanical properties and determine the reliability of these interfaces prior to use in automotive power electronics applications. In this paper, research efforts at the National Renewable Energy Laboratory, in collaboration with Virginia Polytechnic Institute and State University and an industry partner, in optimizing the synthesis procedure and mechanical characterization of sintered silver double-lap samples are described. These double-lap samples were synthesized using pressure-less sintering techniques. Shear testing was conducted at multiple temperatures and displacement rates on these samples sintered using two types of sintered sintered silver pastes, one of them consisting of nano-silver particles and the other a hybrid paste or a combination of nano- and micron-sized silver flakes, employed in a double-lap configuration. Maximum values of shear stress obtained from the characterization study are reported.


2019 ◽  
Vol 817 ◽  
pp. 365-370 ◽  
Author(s):  
Alessandro Bellini ◽  
Marco Bovo ◽  
Andrea Incerti ◽  
Claudio Mazzotti

Structural retrofitting with composite materials proved to be an effective technique for rehabilitation of degraded or damaged masonry and concrete buildings. Nowadays, Fiber Reinforced Cementitious Matrix (FRCM) composites are widely used as externally bonded strengthening systems thanks to their high performance, low weight and easiness of installation. Several experimental tests and numerical studies are currently available concerning the tensile and bond behavior of FRCM systems, but a debated and still open issue concerns the methods for the mechanical characterization of the mortar used as matrix within the strengthening system. The present paper analyses and compares different test methods for determining the matrix tensile strength. Pure tensile and flexural tests have been carried out on different mortar matrix samples. In order to evaluate which is the most suitable value to be considered for a correct interpretation and modeling of the composite system, the experimental results obtained through flexural tests on standard mortar specimens have been compared with the outcomes obtained from direct tensile tests on FRCM coupons. The present study represents only a first step for the definition of the most appropriate test method for the mechanical characterization of the matrix used within FRCM strengthening systems.


2017 ◽  
Vol 889 ◽  
pp. 56-62 ◽  
Author(s):  
D.S. Robinson Smart ◽  
Nithin P. Johns ◽  
Joses Jenish Smart

Aluminium composites are widely used in a variety of applications including aerospace, automotive, defence, thermal as well as in sports and avocation. Technological and industrial demands often account to inculcating special properties to materials to achieve its target that may not be achieved by conventional materials. This phenomenon was widely observed in the recent decades in fields of aerospace and transport where high performance materials with low densities are required. The primary objective of this work is to develop an Aluminium Metal Matrix Composite (AMMC) by in-situ stir casting for naval applications and successfully bring about self-lubrication properties, thereby lowering wear rate and improving corrosion resistance. This is done by adding graphite at various weight fractions to the base metal. The fabricated composites are subjected to various mechanical tests and corrosion test. It was found that ,increase in graphite addition improves the Microhardness of the material, improves the wear resistance and enhances its corrosion resistance. The materials were further observed and found that , there will be lower tensile strengths compared to the base metal with increase in addition of graphite particles.


2020 ◽  
Vol 988 ◽  
pp. 206-211
Author(s):  
Alfirano ◽  
Purwaningtyas Agustini ◽  
Sumirat Iwan

Co-Cr-Mo alloys is the material used as a biomedical implant in human body. This material is widely used because they have excellent in corrosion and wear resistance. In this study, microstructure and results of tensile test that were affected by carbon and nitrogen were investigated. The specimens of Co-Cr-Mo alloy were made by investment casting. The compositions of the alloys are Co-28Cr-6Mo-0.8(Si, Mn, Fe)-0,2Ni-(0.08-0.25)C-(0-0.2)N. After that process, microstructure of the alloys is characterized by, SEM/EDX and XRD testing using bulk and electrolytic extracted specimens. The mechanical properties were determined by tensile test. The precipitate content in as-cast alloys was higher when carbon and nitrogen was added. The main precipitate formed in the specimens with variations in carbon and nitrogen is M23X6 type, π-phase, χ-phase, and σ-phase. Carbon and nitrogen promoted M23X6 type and π-phase precipitation, respectively, meanwhile χ-phase was formed in the alloys with low carbon content. The addition of carbon and nitrogen shows an increased in yield strength, tensile strength and elongation of as-cast Co-28Cr-6Mo-0.8(Si, Mn, Fe)-0,2Ni-(0.08-0.25)C-(0-0.2)N alloys.


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