scholarly journals Effect of Ti on the Structure and Mechanical Properties of TixZr2.5-xTa Alloys

Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1632
Author(s):  
Bin Zhang ◽  
Yu Tang ◽  
Shun Li ◽  
Yicong Ye ◽  
Li’an Zhu ◽  
...  

To determine the effects of Ti and mixing entropy (ΔSmix) on the structure and mechanical proper-ties of Zr-Ta alloys and then find a new potential energetic structural material with good me-chanical properties and more reactive elements, TixZr2.5−xTa (x = 0, 0.5, 1.0, 1.5, 2.0) alloys were investigated. The XRD experimental results showed that the phase transformation of TixZr2.5−xTa nonequal-ratio ternary alloys depended not on the value of ΔSmix, but on the amount of Ti atoms. With the addition of Ti, the content of the HCP phase decreased gradually. SEM analyses revealed that dendrite morphology and component segregation increasingly developed and then weakened gradually. When x increases to 2.0, TixZr2.5−xTa with the best mechanical properties can be ob-tained. The yield strength, compressive strength and fracture strain of Ti2.0Zr0.5Ta reached 883 MPa, 1568 MPa and 34.58%, respectively. The dependence of the phase transformation and me-chanical properties confirms that improving the properties of Zr-Ta alloys by doping Ti is feasible.

2013 ◽  
Vol 683 ◽  
pp. 145-149
Author(s):  
Xing Lei Hu ◽  
Ya Zhou Sun ◽  
Ying Chun Liang ◽  
Jia Xuan Chen

Monte Carlo (MC) method and molecular dynamics (MD) are combined to analyze the influence of ageing on mechanical properties of machined nanostructures. Single crystal copper workpiece is first cut in MD simulation, and then the machined workpiece is used in MC simulation of ageing process, finally the tensile mechanical properties of machined nanostructures before and after ageing are investigated by MD simulation. The results show that machining process and ageing have obvious influence of tensile mechanical properties. After machining, the yield strength, yield strain, fracture strain and elastic modulus reduce by 36.02%, 28.86%, 20.79% and 7.16% respectively. However, the yield strength, yield strain and elastic modulus increase by 4.84%, 1.41% and 1.02% respectively, fracture strain reduce by 24.53% after ageing process. To research the ageing processes of machined nanostructures by MC simulation is both practical and meaningful.


Ceramics ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Manohar Mattli ◽  
Penchal Matli ◽  
Abdul Shakoor ◽  
Adel Amer Mohamed

The present study focuses on the synthesis and characterization of amorphous silicon nitride (Si3N4) reinforced aluminum matrix nanocomposites through the microwave sintering process. The effect of Si3N4 (0, 1, 2 and 3 wt.%) nanoparticles addition to the microstructure and mechanical properties of the Al-Si3N4 nanocomposites were investigated. The density of Al-Si3N4 nanocomposites increased with increased Si3N4 content, while porosity decreased. X-ray diffraction (XRD) analysis reveals the presence of Si3N4 nanoparticles in Al matrix. Microstructural investigation of the nanocomposites shows the uniform distribution of Si3N4 nanoparticles in the aluminum matrix. Mechanical properties of the composites were found to increase with an increasing volume fraction of amorphous Si3N4 reinforcement particles. Al-Si3N4 nanocomposites exhibits higher hardness, yield strength and enhanced compressive performance than the pure Al matrix. A maximum increase of approximately 72% and 37% in ultimate compressive strength and 0.2% yield strength are achieved. Among the synthesized nanocomposites, Al-3wt.% Si3N4 nanocomposites displayed the maximum hardness (77 ± 2 Hv) and compressive strength (364 ± 2 MPa) with minimum porosity level of 1.1%.


Author(s):  
M. N. Meiirbekov ◽  
◽  
M. B. Ismailov ◽  

The paper presents published data on the effect of rubber elastomers on the strength properties of epoxy resin (ES) and carbon fiber. The introduction of 10% rubbers into ES ED-20 leads to an increase in compressive strength by 50%, tensile strength by 51%, impact strength by 133% and elongation by 128%. The optimal content of rubber with carboxyl groups for the OLDEN mixture was 10-12.5%, while the increase in compressive strength was 48%, impact strength - 73% and elongation - 187%. For DER 331 resin, the study was conducted with two hardeners Piperidine and DETA. The best results for Piperidine hardener were obtained on rubber with hydroxyl groups, with its optimal content of 2.5%, impact strength increased by 170%. For the hardener DETA, the best results were obtained on rubber with carboxyl groups at its optimal content of 10%, the increase in impact strength was 66%. When modifying carbon fiber with rubbers, it leads to a significant increase in the yield strength in tension by 42%, the modulus of elasticity in bending by 63%, and with a slight loss of impact strength.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1464 ◽  
Author(s):  
Feng Qiu ◽  
Xiangzheng Duan ◽  
Baixin Dong ◽  
Hongyu Yang ◽  
Jianbang Lu ◽  
...  

: In situ micro-TiB2/Cu cermets with a different TiB2 content (40, 50, and 60 vol %) were successfully fabricated by combustion synthesis (CS) and hot press consolidation in Cu-Ti-B systems. In addition, different contents of Cr and Zr were added to the Cu-Ti-B systems. The microstructure, mechanical properties, and abrasive wear properties of the TiB2/Cu cermets were investigated. As the ceramic content increased, the yield strength and compressive strength of the cermets were found to increase, while the strain decreased. An increase in load and abrasive particle size caused the wear volume loss of the TiB2/Cu cermets to increase. When the ceramic content was 60 vol %, the wear resistance of the TiB2/Cu cermets was 3.3 times higher than that of pure copper. The addition of the alloying elements Zr and Cr had a significant effect on the mechanical properties of the cermets. When the Cr content was 5 wt %, the yield strength, ultimate compressive strength, and microhardness of the cermets reached a maximum of 997 MPa, 1183 MPa, and 491 Hv, respectively. Correspondingly, when the Zr content was 5 wt %, those three values reached 1764 MPa, 1967 MPa, and 655 Hv, respectively, which are 871 MPa, 919 MPa, and 223 Hv higher than those of the unalloyed cermets. The wear mechanism of the in-situ TiB2/Cu cermets, and the mechanisms by which the strength and wear resistance were enhanced by the addition of Zr, were preliminarily revealed.


2018 ◽  
Vol 53 (2) ◽  
pp. 183-196
Author(s):  
Z Nouri ◽  
M Sedighi ◽  
H Minouei

In the present study, the semisolid forming has been proved to be effective in fabricating amorphous reinforced aluminum matrix composite of high quality with appreciable mechanical properties. In other words, the Ni60Nb40 glassy reinforcement in 520.0 aluminum matrix composite was successfully fabricated via powder thixoforging without altering the glassy nature. Most prior studies are focused on solid state (powder metallurgy). Subsequently, the use of glassy particles with high crystallization temperatures provides processing the composite at higher temperatures. Considering the powder thixoforming benefits, we open a door to another way of manufacturing high-efficient amorphous reinforced metal matrix composite with brilliant mechanical properties. In monolithic matrix, the alloy produced via powder thixoforging hardness and compression yield strength reached 223(HV) and 747 MPa compared to as cast condition increase of 116% and 228%, respectively. Additionally, this significant mechanical strength was combined with a brilliant fracture strain of 40%. Moreover, the 30 vol.% glassy reinforced composite possess hardness, compression yield strength, and fracture strain of 311(HV), 875 MPa, and 13%, respectively. All produced specimens reached near full density over 99% relative density, leading to a considerable combination of superior strength and ductility. Significantly, the SYS of powder thixoforging samples significantly increased from 89 kN m kg−1 for as cast condition to 290, 238, 220, and 199 kN m kg−1 for the monolithic and amorphous reinforced Al matrix composites of 12, 20 and 30 vol.%.


2020 ◽  
Vol 2020 ◽  
pp. 1-21 ◽  
Author(s):  
Rui Song ◽  
Lifu Zheng ◽  
Yao Wang ◽  
Jianjun Liu

As porous, heterogeneous, and anisotropic material, the microscopic structure of the rock has a significant influence on its mechanical properties. Rare studies were devoted to this area using pore scale modeling and simulations. In this paper, different types of sandstones are imaged using micro-CT technology. The rock porosity is obtained by filtering, binarization, and threshold segmentation. The texture coefficient (TC) and the tortuosity of the rock skeleton are calculated by open source program, where the tortuosity of the rock skeleton is firstly used to characterize the microscopic structure of the rock. Combining with the rock mechanics parameters obtained in the laboratory, the simulation of uniaxial compression is performed on the reconstructed pore scale rock finite element mesh model by ANSYS software. Young’s modulus, compressive strength, yield strength, shear modulus, and other related parameters obtained by numerical simulation are adopted to determine the optimal representative volume element (RVE) size. Moreover, the effects of microscopic structure characteristics on the mechanical properties of the rock are studied quantitatively. The results indicate that the averaged von Mises stress distribution, displacement field, and plastic strain field of rocks show anisotropy and heterogeneity. The stress concentration and the X-shaped conjugate plastic shear zone are investigated. The samples of S1∼S4 reach the elastic limit and enters the plastic yield state, when the strain is about 0.5%. And the critical yield strain of samples S5300-1∼S5400-2 is about 1%. Then, the quantitative relationships between porosity, TC, tortuosity of rock skeleton and rock mechanics parameters of digital rock samples are established and analyzed. The tortuosity of the rock skeleton is highly correlated with the mechanical parameters of the rock, i.e., Young’s modulus (R2 = 0.95), compressive strength (R2 = 0.94), yield strength (R2 = 0.92), and shear modulus (R2 = 0.94), which is believed to be more feasible to reveal the impacts of the microstructure of the rock on its mechanical properties.


2005 ◽  
Vol 488-489 ◽  
pp. 249-252 ◽  
Author(s):  
J. Cai ◽  
Li Lin ◽  
Zhen Liu ◽  
Hai Feng Zhang ◽  
Zhuang Qi Hu

Bulk AZ91HP rods with a diameter of 8mm were prepared by copper mould casting. The microstructure and mechanical properties have been studied. The compressive strength, yield strength, elongation and microhardness of the rapidly solidified AZ91HP alloy are 392MPa, 183 MPa, 3.6% and HV87, respectively. It results from grain refinement and reinforcement of β-Mg17Al12 phase.


Author(s):  
K Das Chowdhury ◽  
R. W. Carpenter ◽  
W. Braue

Research on reaction-bonded SiC (RBSiC) is aimed at developing a reliable structural ceramic with improved mechanical properties. The starting materials for RBSiC were Si,C and α-SiC powder. The formation of the complex microstructure of RBSiC involves (i) solution of carbon in liquid silicon, (ii) nucleation and epitaxial growth of secondary β-SiC on the original α-SiC grains followed by (iii) β>α-SiC phase transformation of newly formed SiC. Due to their coherent nature, epitaxial SiC/SiC interfaces are considered to be segregation-free and “strong” with respect to their effect on the mechanical properties of RBSiC. But the “weak” Si/SiC interface limits its use in high temperature situations. However, few data exist on the structure and chemistry of these interfaces. Microanalytical results obtained by parallel EELS and HREM imaging are reported here.


2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.


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