scholarly journals Improving Mechanical, Thermal and Damping Properties of NiTi (Nitinol) Reinforced Aluminum Nanocomposites

2020 ◽  
Vol 4 (1) ◽  
pp. 19 ◽  
Author(s):  
Penchal Reddy Matli ◽  
Vyasaraj Manakari ◽  
Gururaj Parande ◽  
Manohar Reddy Mattli ◽  
Rana Abdul Shakoor ◽  
...  

In the present study, Ni50Ti50 (NiTi) particle reinforced aluminum nanocomposites were fabricated using microwave sintering and subsequently hot extrusion. The effect of NiTi (0, 0.5, 1.0, and 1.5 vol %) content on the microstructural, mechanical, thermal, and damping properties of the extruded Al-NiTi nanocomposites was studied. Compared to the unreinforced aluminum, hardness, ultimate compression/tensile strength and yield strength increased by 105%, 46%, 45%, and 41% while elongation and coefficient of thermal expansion (CTE) decreased by 49% and 22%, respectively. The fabricated Al-1.5 NiTi nanocomposite exhibited significantly higher damping capacity (3.23 × 10−4) and elastic modulus (78.48 ± 0.008 GPa) when compared to pure Al.

2012 ◽  
Vol 538-541 ◽  
pp. 326-330
Author(s):  
Zeng Lei Ni ◽  
Ai Qin Wang ◽  
Jing Pei Xie ◽  
Ming Fang ◽  
Li Jun Zhang

α-SiC particles have been processed with surface treatment of high-temperature calcination and water washing technology. SiCp/Al-30Si composite has been prepared in the vacuum hot extrusion process. The powder morphology and specimens microstructure have been observed using scanning electron microscopy, the phase of SiC has been analyzed using the X-ray diffraction. Meanwhile, the tensile strength and thermal expansion coefficient of the composite have been tested. The effects of the morphology of the SiC particles, tensile strength and thermal expansion coefficient have been studied on composite microstructure. The consequences show that, after the surface treatment SiCp/Al-30Si composite,the interfaces combined with matrix are in a better condition and less holes, the tensile strength of composite materials has been improved significantly, the coefficient of thermal expansion becomes lower than before.


2017 ◽  
Vol 898 ◽  
pp. 97-103 ◽  
Author(s):  
Zheng Hua Huang ◽  
Nan Zhou ◽  
Jing Xu ◽  
Yang De Li ◽  
Wei Rong Li

The microstructures, phase constitutions and mechanical properties of as-cast samples, extruded rods and plates of Mg-3.52Sn-3.32Al and Mg-6.54Sn-4.78Al alloys were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction and mechanical testing. The results show that as-cast microstructure consists of α-Mg matrix, Mg2Sn and a few dispersed β-Mg17Al12 phases. The two as-cast alloys exhibit good tensile mechanical properties. After hot extrusion, dynamic recrystallization occurs. Average grain size reaches 6 μm ~ 8 μm for rods, and a lot of fine micro-scaled particles exist, resulting in significant enhancement of tensile mechanical properties. The extruded Mg-3.52Sn-3.32Al rod exhibits better comprehensive tensile mechanical property than AZ31B alloy, with tensile strength σb of 295 MPa, yield strength of 200 MPa and elongation of 21.5% at ambient temperature. The extruded Mg-6.54Sn-4.78Al rod exhibits equivalent comprehensive tensile mechanical properties with ZK60 alloy, achieving tensile strength of 355 MPa, yield strength of 275 MPa and elongation of 11% at ambient temperature. The extruded plates at ambient temperature performed a tensile strength of 270 MPa.


2019 ◽  
Vol 950 ◽  
pp. 65-69
Author(s):  
Sun Fei ◽  
Xu Cheng

In order to study the effect of temperature on the mechanical properties of H90 copper strip material, the H90 copper strip test pieces were heated to different temperatures (20~600 °C) for tensile test; the yield strength, tensile strength, elastic modulus and elongation of H90 copper strip at different temperatures were obtained. Based on the test results, the empirical models of yield strength, tensile strength, elastic modulus of H90 copper strip at high temperature were established; the test showed that, with the increase of temperature, the yield strength, tensile strength and elastic modulus of H90 copper strip decreased greatly, and the elongation after fracture first increased-decreased-increased at 20~600 °C. The study results in this paper provide basic material data for analyzing the effect of temperature on the continuous firing of firearms and other weapons.


2009 ◽  
Vol 24 (1_suppl) ◽  
pp. 158-168 ◽  
Author(s):  
Hai Lu ◽  
Wei-Jun Chen ◽  
Yan Xing ◽  
Da-Jun Ying ◽  
Bo Jiang

A biomaterial patch of electrospun collagen type fibers was designed and produced by electrospinning seven different concentrations (8%-20% w/v) of collagen solutions. The tensile strength, yield strength, and elastic modulus of the electrospun collagen fibrous patches were found to be suitable for clinical transplantation. No significant differences versus fresh porcine pericardium as controls were observed. The SEM images of the groups showed that the patches were smooth with uniform interwoven and porous morphology. The fibrous patches were biocompatible and did not elicit local or systemic toxic effects when implanted in vivo. These electrospun collagen fibrous patches have significant potential as surgical biomaterial patches.


APL Materials ◽  
2018 ◽  
Vol 6 (7) ◽  
pp. 076105 ◽  
Author(s):  
Yuan Lu ◽  
Markus Reusch ◽  
Nicolas Kurz ◽  
Anli Ding ◽  
Tim Christoph ◽  
...  

2016 ◽  
Vol 861 ◽  
pp. 147-152
Author(s):  
Fei Yang ◽  
Brian Gabbitas ◽  
Ajit Singh ◽  
Chung Fu Wang

In this paper, pure titanium rods, with high strength and ductility, were prepared by vacuum sintering titanium powder compacts at 1300oC for 2h and then hot extruding the as-sintered titanium billets at 900oC in air. The microstructure and property changes, after vacuum sintering and hot extrusion, were investigated. The results showed clear evidence of porosity in the microstructure of as-sintered titanium billet and tensile testing of as-sintered material gave yield strength, ultimate tensile strength and ductility values of 570MPa, 602MPa and 4%, respectively. After extrusion at 900oC, no obvious pores could be seen in the microstructure of as-extruded titanium rod, and the mechanical properties were significantly improved. The yield strength, ultimate tensile strength and the ductility reached 650MPa, 705MPa and 20%, respectively, which are much higher than values for CP titanium (grade 4), with a yield strength of 480MPa, ultimate tensile strength of 550MPa and ductility of 15%. The fracture characteristics of as-sintered and as-extruded titanium rods have also been investigated.


2021 ◽  
Vol 63 (2) ◽  
pp. 191
Author(s):  
М.Н. Магомедов

Using the previously developed method for calculating crystal properties based on the Mie–Lennard-Jones pair potential, the thermodynamic properties of the BCC and FCC phases of iron at the temperature of the polymorphic BCC-FCC phase transition are calculated. 23 properties of iron and their changes during the BCC-FCC transition are calculated. Calculations have shown that properties such as the Gruneisen parameter, the coefficient of thermal expansion, and the heat capacity practically do not change during the BCC-FCC transition. The elastic modulus, specific entropy, Poisson's ratio, and specific surface energy change in the same way as the molar volume, i.e. within 1%. The Debye temperature and its pressure derivative decrease at the BCC-FCC transition in the same way as the distance between the centers of the nearest atoms increases, i.e. within 2-3%. Based on the analysis of experimental data known from the literature, it is shown that even relatively accurately measured parameters such as the coefficient of thermal expansion and elastic modulus are measured with an error exceeding the values of jumps in these parameters at the BCC-FCC transition. It is indicated that amorphization or nanostructuring of a certain portion of iron during the BCC-FCC transition can contribute to changes in the properties of iron during this phase transition.


2019 ◽  
Vol 34 (15) ◽  
pp. 2714-2726 ◽  
Author(s):  
Ruibin Yang ◽  
Junrui Yang ◽  
Kun Xie ◽  
Zhongxia Liu ◽  
Guotao Zhang

Abstract


1988 ◽  
Vol 134 ◽  
Author(s):  
J. Im ◽  
P.A. Percha ◽  
D.S. Yeakle

ABSTRACTThe tensile properties of poly (paraphenylene benzobisoxazole) or PBO fiber strands were studied using two variables: gage length and the number of twists per inch. The gage length was varied from 1 to 10 inches with 2 twists of the fiber per inch. The effect of the number of twists per inch was studied by varying the number of twists from zero to 10 along a 5-inch gage length. The trends of tensile strength and modulus due to these variables were established and appropriate explanations of these behaviors are provided.The coefficient of thermal expansion (CTE) was studied on bare strands of PBO and Kevlar 49 (a product of Du Pont de Nemours & Co.) fibers, using a Du Pont 943 Thermomechanical Analyzer (TMA) equipped with a film and fiber tension assembly. The axial CTE of both fibers exhibited a dependence on the small dead load employed to keep the fibers straight. Kevlar 49 fiber, when wet, attained a much less negative value of CTE than when dry. In contrast, PBO fiber absorbed very little moisture, and the CTE remained unchanged.


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