scholarly journals Effect of Compression Process of MWCNT-Reinforced Al6061 Powder on Densification Characteristics and Its Mechanical Properties

Metals ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 437 ◽  
Author(s):  
Hyung Seo ◽  
Long Jiang ◽  
Chung Kang ◽  
Chul Jin
BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3566-3584
Author(s):  
Qingde Li ◽  
Yingyi Liang ◽  
Feng Chen ◽  
Tonghui Sang

Wood fiber was modified by impulse-cyclone drying treatment with poplar and montmorillonite as reinforcing materials; mMMT/polypropylene/wood fiber foaming composite was prepared by the hot compression process. The effects of modification, temperature, and content of montmorillonite on physical and mechanical properties of the composite were analyzed. Mechanical properties, porosity, shrinkage, water absorption, and thickness swelling tests showed that when mMMT reinforcement was 5 wt%, the best performance was achieved. The scanning electron microscopy observations showed that bubble holes were distributed widely and evenly, and mMMT appeared in the cell gap and was encapsulated by polypropylene, which maximized the bonding effect. Flexural strength was 27.5 MPa, flexural modulus was 2110 MPa, tensile strength was 20.0 MPa, and impact strength was 6.30 KJ/m2. When absolute volume of dense solid reached 70.8 cm3, porosity was 21.4% and shrinkage was 1.17%, which indicated that the water absorption increased most remarkably under that test condition. When equilibrium water absorption reached 9.28%, the thickness swelling decreased by 25%. The results showed that mMMT effectively optimized mechanical properties of wood-based foamed composites and improved hygroscopic properties.


2011 ◽  
Vol 217-218 ◽  
pp. 1123-1128
Author(s):  
Jun Wei Liu ◽  
Shi Qiang Lu ◽  
Xian Juan Dong ◽  
Xuan Xiao

The microstructural evolution and mechanical properties of as cast AZ91 Mg alloy enduring different homogenization conditions were researched. The results show that the peak stress and plasticity obtain improvement with the increase of heat treated time and temperature until 693K. When the temperature is higher than 743K, the sample will occur the over-burned and directly lead to the decrease of mechanical properties. Otherwise, with the increase of heat treated time and temperatures, the second phase gradually precipitate from the solution, while the grain evolution is not obvious. In the compression process for the samples after heat treatment, some twins could be found in the grains.


2007 ◽  
Vol 334-335 ◽  
pp. 829-832
Author(s):  
Joon Hyung Byun ◽  
Kyeong Sik Min ◽  
Yeun Ho Yu ◽  
Moon Kwang Um ◽  
Sang Kwan Lee

This study describes a method of good dispersion and alignment of VGCFs, and examines the effect of nanofiber content on the mechanical properties of nanocomposites. The dispersion of nanofibers was carried out by solution blending, mechanical mixing, and sonication. Levels of 4% – 31% volume content of VGCFs were mixed with polypropylene (PP) powder, and then were melt-mixed using a twin-screw extruder. For the further alignment of fibers, extruded rods were stacked in the mold cavity for the compression molding. In the case of 31% volume content, tensile modulus and strength improved by 100% and 40%, and the flexural modulus and strength increased by 120% and 25%, respectively. The shear modulus showed 65% increase, but the strength dropped sharply by 40%. In the transverse direction, the tensile, flexural, and shear strength decreased as more fibers were added. The matrix modification by maleic anhydride (MAPP) increased the tensile and flexural properties of VGCF/PP by 20% - 30% in the longitudinal direction, and 40% - 250% increase in the transverse direction. The fiber surface treatment by plasma improved tensile and flexural properties of untreated VGCF/PP (18 % vol) composites by 10% - 30% in the longitudinal direction, but strength in the transverse direction decreased by 30% - 40%.


2021 ◽  
Vol 36 (16) ◽  
pp. 3203-3213
Author(s):  
Xiaotong Feng ◽  
Zhijie Lin ◽  
Kai Xin ◽  
Weiwei Pang

Author(s):  
Mina Bastwros ◽  
Gap-Yong Kim ◽  
Kun Zhang ◽  
Shiren Wang

A composite made of graphene and aluminum is a promising material for many engineering applications due to its lightweight and relatively high strength properties. Unfortunately, the uniform dispersion of the graphene is considered one of the big challenges since the graphene clusters tend to deteriorate the mechanical properties of the composite. In this study, a graphene reinforced Al6061 composite has been investigated. The composites are fabricated by ball milling the graphene flakes and the Al6061 powder, followed by hot compaction in the semi-solid regime of the Al6061. In addition, a graphene reinforced composite with localized reinforced zones within the composite was also investigated The mechanical properties of the composites are measured by conducting a bend test, and microstructural analysis of the composite and fracture surfaces are performed. According to the bending test results, an enhancement in the strength is clearly observed.


Author(s):  
Mina Bastwros ◽  
Gap-Yong Kim ◽  
Can Zhu ◽  
Kun Zhang ◽  
Shiren Wang

Graphene is a promising material as a reinforcing element for high-strength, lightweight metal composites due to its extraordinary mechanical properties and low density. In this study, Al6061–graphene composite was investigated with 1.0 wt.% graphene reinforcement. The graphene was manufactured by the modified Brodie’s method. The Al6061 powder and graphene flakes were ball milled at different milling times (10, 30, 60, and 90 min). The composite was then synthesized by hot compaction in the semi-solid regime of the Al6061. Three point bending test was performed to characterize the mechanical properties of the composites. The ball milled powder and the fracture surfaces of the composites were investigated using the scanning electron microscopy (SEM). The results were compared with a reference Al6061 without any graphene reinforcement. For the Al6061-1.0 wt.% graphene composites, a maximum enhancement of 47% in the flexural strength was observed when compared with the reference Al6061 processed at the same condition.


2019 ◽  
Vol 252 ◽  
pp. 08005 ◽  
Author(s):  
Liwia Sozańska-Jędrasik ◽  
Janusz Mazurkiewicz ◽  
Wojciech Borek

The aim of the work was to analyse the impact of an eight-stage hot compression process carried out on the Gleeble3800 simulator, with three cooling variants after thermo-mechanical treatment of Fe-Mn-Al-C steels for their structure and mechanical properties. Performed research allowed to evaluate the impact on the structure and properties of simulation conditions for multi-stage rolling of difficult-to-treat thermomechanical steels for which this treatment is the final process of obtaining ready-to-use high-strength construction steels. Applied thermo-mechanical treatment causes that the main process of removing the effects of strain hardening is dynamic recovery, and static and metadynamic recrystallisation taking place after the last deformation but also between successive deformations, which was also confirmed on the basis of structural analysis of the tested steel after different cooling variants. As a result of the eight-stage hot compression test, the ferrite changed its distribution from fine grains occurring at the boundaries of austenite grains after forging, to elongated grains in a perpendicular direction to the compression direction. Isothermal heating at 850°C for 30s resulted in obtaining a fine-grained structure, statically or metadynamically recrystallised. The maximum tensile strength of the tested steels is about 1250 MPa, and the total elongation value is about 27%.


2019 ◽  
Vol 171 ◽  
pp. 52-56 ◽  
Author(s):  
Tyler J. Flanagan ◽  
Benjamin A. Bedard ◽  
Avinash M. Dongare ◽  
Harold D. Brody ◽  
Aaron Nardi ◽  
...  

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