scholarly journals Effect of Nb on the Microstructure and Mechanical Properties of Ti2Cu Intermetallic through the First-Principle Calculations and Experimental Investigation

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 547 ◽  
Author(s):  
Jialin Cheng ◽  
Yeling Yun ◽  
Jingjing Wang ◽  
Jiaxin Rui ◽  
Shun Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Density Functional ◽  
Covalent Bond ◽  
First Principle ◽  
Compression Tests ◽  
Solid Solution Strengthening ◽  
First Principle Calculations ◽  
Fine Grain ◽  
Fine Grain Strengthening

Through the first-principle calculations based on density functional theory and experimental investigation, the structural stability elastic properties and mechanical properties of Ti2Cu and Ti18Cu5Nb1 intermetallics were studied. The first-principle calculations showed that the ratio of bulk modulus to shear modulus (B/G) and Poisson’s ratio (ν) of Ti2Cu and Ti18Cu5Nb1 intermetallics were 2.03, 0.288, and 2.22, 0.304, respectively, indicating that the two intermetallics were ductile. This was confirmed by the compression tests, which showed that the plastic strain of both intermetallics was beyond 25%. In addition, the yield strength increased from the 416 to 710 MPa with the addition of Nb. The increase in strength is the result of three factors, namely covalent bond tendency, fine grain strengthening, and solid solution strengthening. This finding gives clues to design novel intermetallics with excellent mechanical properties by first-principle calculations and alloying.

Vacancy-induced elastic properties and hardness of CrB4: A DFT calculation

2017 ◽  
Vol 31 (13) ◽  
pp. 1750096 ◽  
Author(s):  
Yong Pan ◽  
Song Chen ◽  
Yuanhua Lin
Keyword(s):  
Mechanical Properties ◽  
Dft Calculation ◽  
Covalent Bond ◽  
Elastic Stiffness ◽  
First Principle ◽  
Triangular Pyramid ◽  
First Principle Calculations ◽  
3D Network ◽  
Metal Borides ◽  
The Relationship

Vacancy plays a crucial role in mechanical properties of transition metal borides (TMBs). However, the influence of vacancy on hardness of TMBs is unknown. In this paper, the relationship between boron vacancy and mechanical properties of CrB4 is investigated by first-principle calculations. Two different vacancies including boron monovacancy (MV) and boron bivacancy (BV) are considered. We find that CrB4 with boron MV is more stable than that of boron BV. The removed atom weakens the deformation resistances, and reduces the elastic stiffness and hardness. The calculated shear modulus, Young’s modulus and theoretical hardness of boron MV are larger than that of boron BV. The reason is that the removed atom weakens the localized hybridization between B and B atoms, and damages the 3D-network B–B covalent bond. However, the bulk modulus of B[Formula: see text] is slightly larger than that of perfect CrB4. This reason is attributed to the formation of triangular pyramid bonding in B[Formula: see text] vacancy.

Microstructure and Mechanical Properties of Backward-Extruded Mg-Zn-xCa Biomaterials

2013 ◽  
Vol 747-748 ◽  
pp. 426-430
Author(s):  
Xue Jun Li ◽  
Hui Li ◽  
Shuang Shuang Zhao ◽  
Ning Ma ◽  
Qiu Ming Peng
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Solid Solution Strengthening ◽  
Backward Extrusion ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Microstructure And Mechanical Properties ◽  
Solution Strengthening ◽  
Extrusion Technology ◽  
Precipitate Strengthening

The Mg-1.0Zn-xCa (x=0.2, 0.5, 0.8, 1 wt. %) alloys were prepared by zone solidification and backward extrusion technology. The microstructure and mechanical properties of backward-extruded Mg-1.0Zn-xCa alloys were investigated. The results showed that these backward-extruded Mg-1.0Zn-xCa alloys were mainly composed of equi-axed pentagon-shaped grains and some Mg0.9Zn0.03 precipitates. The tensile and compressive strengths of backward-extruded Mg-1.0Zn-xCa alloys were greatly improved. The improved mechanical properties are mostly attributed to fine grain strengthening, solid solution strengthening and precipitate strengthening. The results demonstrated that the micro alloying of Ca element was one of effective method to improve the mechanical properties of Mg-1.0Zn based biomaterials.

scholarly journals Effect of Sm Doping on the Microstructure, Mechanical Properties and Shape Memory Effect of Cu-13.0Al-4.0Ni Alloy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4007
Author(s):  
Qimeng Zhang ◽  
Bo Cui ◽  
Bin Sun ◽  
Xin Zhang ◽  
Zhizhong Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Strengthening Effect ◽  
Face Centered Cubic ◽  
Compressive Fracture ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Face Centered

The effects of rare earth element Sm on the microstructure, mechanical properties, and shape memory effect of the high temperature shape memory alloy, Cu-13.0Al-4.0Ni-xSm (x = 0, 0.2 and 0.5) (wt.%), are studied in this work. The results show that the Sm addition reduces the grain size of the Cu-13.0Al-4.0Ni alloy from millimeters to hundreds of microns. The microstructure of the Cu-13.0Al-4.0Ni-xSm alloys are composed of 18R and a face-centered cubic Sm-rich phase at room temperature. In addition, because the addition of the Sm element enhances the fine-grain strengthening effect, the mechanical properties and the shape memory effect of the Cu-13.0Al-4.0Ni alloy were greatly improved. When x = 0.5, the compressive fracture stress and the compressive fracture strain increased from 580 MPa, 10.5% to 1021 MPa, 14.8%, respectively. When the pre-strain is 10%, a reversible strain of 6.3% can be obtained for the Cu-13.0Al-4.0Ni-0.2Sm alloy.

In Situ Preparation and Mechanical Properties of (ZrB2+ZrC)/Zr3[Al(Si)]4C6 Composites

2014 ◽  
Vol 602-603 ◽  
pp. 438-442
Author(s):  
Lei Yu ◽  
Jian Yang ◽  
Tai Qiu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Linear Increase ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Uniform Microstructure

Fully dense (ZrB2+ZrC)/Zr3[Al (Si)]4C6 composites with ZrB2 content varying from 0 to 15 vol.% and fixed ZrC content of 10 vol.% were successfully prepared by in situ hot-pressing in Ar atmosphere using ZrH2, Al, Si, C and B4C as raw materials. With the increase of ZrB2 content, both the bending strength and fracture toughness of the composites increase and then decrease. The synergistic action of ZrB2 and ZrC as reinforcements shows significant strengthening and toughing effect to the Zr3[Al (Si)]4C6 matrix. The composite with 10 vol.% ZrB2 shows the optimal mechanical properties: 516 MPa for bending strength and 6.52 MPa·m1/2 for fracture toughness. With the increase of ZrB2 content, the Vickers hardness of the composites shows a near-linear increase from 15.3 GPa to 16.7 GPa. The strengthening and toughening effect can be ascribed to the unique mechanical properties of ZrB2 and ZrC reinforcements, the differences in coefficient of thermal expansion and modulus between them and Zr3[Al (Si)]4C6 matrix, fine grain strengthening and uniform microstructure derived by the in situ synthesis reaction.

First-principle calculations and experimental investigation on the infrared emissivity property of Mg-doped ZnO

2017 ◽  
Vol 95 ◽  
pp. 354-360 ◽  
Author(s):  
Tengchao Guo ◽  
Guoyue Xu ◽  
Shujuan Tan ◽  
Ning Liu ◽  
Jianchao Zhang ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
First Principle ◽  
Infrared Emissivity ◽  
First Principle Calculations ◽  
Doped Zno ◽  
Mg Doped

Comprehensive Strengthening of Microalloyed Pure Gold

2015 ◽  
Vol 713-715 ◽  
pp. 2617-2623
Author(s):  
Jun Ping Yuan ◽  
Chun Yu Ma ◽  
Chang Wang
Keyword(s):  
Solid Solution ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Pure Gold ◽  
Solid Solution Strengthening ◽  
Fine Grain ◽  
Performance Requirements ◽  
Fine Grain Strengthening ◽  
Solution Strengthening ◽  
And Performance

The hardness of pure gold jewellery is low which makes it difficult to meet structural design and performance requirements, and restricts its artistic value. In this research, scandium, calcium, and magnesium were used as alloying elements with pure gold, and the microstructure and hardening behaviour of modified pure gold were studied through cold-working, solid solution, and aging treatment. The results showed that the as-cast hardness of an Sc-Ca-Mg alloyed pure gold could reach HV64: after solution treatment at 700 °C, the hardness could reach HV55, and the microstructure in its solid solution state presented a homogeneous single phase. When the modified pure gold was deformed and the deformation rate reached 80%, the hardness reached HV118, after aging treatment at 250 °C and small precipitation phases were dispersed in its structure; the resultant grain size was finer than that of pure gold, and the hardness reached HV133. The hardening behaviour of this modified pure gold was the comprehensive effect of solid solution strengthening, fine-grain strengthening, deformation strengthening, and precipitation strengthening.

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