Development of Light Weight Alloys and Composites : Microstructure and Properties: Composites III
Program Organizers: Ramasis Goswami, Naval Research Laboratory; Nikhil Gupta, New York University; Tanjore Jayaraman, United States Air Force Academy; Aashish Rohatgi, Pacific Northwest National Laboratory
Tuesday 2:00 PM
October 19, 2021
Room: A214
Location: Greater Columbus Convention Center
Session Chair: Tanjore Jayaraman, College of Engineering and Computer Science, University of Michigan-Dearborn; Ramasis Goswami, NRL
2:00 PM
Development of Bulk Nanocrystalline Aluminum Materials with Enhanced Mechanical Properties: Pradeep Menezes1; Sridhar Lanka1; Raven Maccione1; Bhaskar Vadlamani1; Manoranjan Misra1; 1University of Nevada Reno
Manufacturing bulk nanocrystalline (NC) materials with lightweight and superior mechanical properties have been of considerable interest to material scientists. In the present research, to develop NC materials, powders of Al, and Al-5wt.%Mg alloys, were cryo-milled under controlled liquid nitrogen temperatures for different durations. The cryo-milled powders were characterized using X-ray diffraction, scanning electron microscope, and transmission electron microscope. The crystallite size significantly decreased with increasing cryo-milling duration. Further, spark plasma sintering of cryo-milled Al and Al-Mg powders were carried out to manufacture bulk component. The results showed that the cryo-milled Al and Al-Mg components showed superior mechanical properties compared to non-cryo-milled Al and Al-Mg components. Furthermore, the Al-Mg components were superior to Al components. Moreover, the cryo-milling duration had a significant effect on the strength properties. It can be inferred that the Mg dopant segregated at the grain boundary of Al during cryo-milling and enhanced the strength of the material.
2:30 PM
Tensile Properties of Epoxy Composites Reinforced with Continuous Mixed Natural Fibers: Frederico Margem1; Niander Aguiar1; Fernanda Rangel1; Joćo Dornelas1; 1Uniredentor
The tensile properties of DGEBA/TETA epoxy matrix composites reinforced with different amounts of mixed natural fibers were evaluated. Composites reinforced with up to 30% in volume of long, continuous and aligned mixed natural fibers were tested in an Instron machine at room temperature. The fracture was analyzed by SEM. This one revealed a weak fiber/matrix interface, which could be responsible for the performance of some properties. The results showed significant changes in the mechanical properties with the amount of mixed natural fibers.
3:00 PM
The Effect of Multiple Age Treatment on Mechanical Properties of 7075 Al Alloy: AHM Esfakur Rahman1; Issam Abu-Mahfouz1; Amit Banerjee1; 1Pennsylvania State University Harrisburg
One of the widely used aerospace alloys is 7075 aluminum alloy because of high tensile and compressive strength and good response to exfoliation corrosion. These 7000 aluminum alloy series are hardened by solution heat treatment followed by artificial ageing. Numerous works have been done on artificial ageing which increases strength as the aging temperature increases up to a limit then decreases. Recent trend shows that the strength can be increased more by applying double aging. This research focuses on the effect of multiple aging temperature, time, and pre-age strain hardening on the mechanical and fatigue properties of 7075 aluminum alloys. ASTM standard coupons were machined from an as received aluminum plate and applied different combination of age treatment and strain hardening. The initial results on strength, ductility, fatigue crack growth and precipitation behavior are reported. The fatigue crack growth behavior is being determined using an in-house crack detection method.