Effects of Preparation Processing on Mechanical Properties of TiAl Intermetallic

2007 ◽  
Vol 353-358 ◽  
pp. 1589-1592
Author(s):  
Wen Zhe Chen ◽  
Kai Ping Peng ◽  
Kuang Wu Qian
Keyword(s):  
Mechanical Properties ◽  
Tial Alloy ◽  
Spray Deposition ◽  
Ingot Metallurgy ◽  
Tial Alloys ◽  
Compression Properties ◽  
Different Temperatures ◽  
Strength And Plasticity ◽  
Increasing Temperature ◽  
The Relationship

Mechanical properties of the TiAl alloy produced by centrifugal spray deposition (CSD), compared to that produced by ingot metallurgy (IM), were investigated at different temperatures from 293 to 973K. The result shows that the ultimate strength, yield strength and plasticity of the CSD TiAl alloys, with excellent compression properties and plasticity, are higher than those of as-cast TiAl alloys at room temperature as well as at high temperature. There exists a critical temperature of 873K in the relationship between strength and temperature, in which strength increases with increasing temperature above 873K. The effects of CSD on mechanical properties of the TiAl alloy are discussed, and the higher strength with moderate ductility achieved is because of the finer lamellar structure got in the CSD processing, and this structure is also believed to be beneficial to ductility.

Effects of Forming Processing on Mechanical Properties of Ti-48Al-2Mn-2Nb Intermetallics

2005 ◽  
Vol 297-300 ◽  
pp. 471-476 ◽  
Author(s):  
Wen Zhe Chen ◽  
Kai Ping Peng ◽  
Kuang Wu Qian ◽  
Hai Cheng Gu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Tial Alloy ◽  
Spray Deposition ◽  
Tensile Elongation ◽  
Hot Isostatic Pressing ◽  
Compressive Properties ◽  
Tial Alloys ◽  
Deformation And Fracture ◽  
Better Than

Ti-48Al-2Mn-2Nb alloy was produced by “centrifugal spray deposition” (CSD), and then hot isostatic pressing (HIP) was employed to remove the porosity formed by CSD. The effects of CSD and HIP processing on the mechanical properties and microstructure of the TiAl alloy were investigated. The results show that the CSD and HIP processing can both improve the strength, plasticity of the TiAl alloy, and the tensile elongation values of the CSD or HIP samples are around 3%, which are better than those of as-cast TiAl alloys in room temperature. Especially, they show more excellent compressive properties at ambient temperature with a compressive ratio of 33.8% and compressive strength of 2210MPa for the CSD samples, and a compressive ratio of 37.8% and compressive strength of 2348MPa for the HIP samples. The CSD processing also improves the fracture toughness of TiAl alloy, which is much higher than that of the HIP processing, while the HIP processing seems to be beneficial the ductility and plasticity as having a duplex structure. The effects of CSD and HIP processing on microstructure and properties of TiAl alloys are discussed to understand the deformation and fracture process of the alloy.

scholarly journals Influence of Temperature on Mechanical Properties of P(BAMO-r-THF) Elastomer

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2507
Author(s):  
Jinxian Zhai ◽  
Hanpeng Zhao ◽  
Xiaoyan Guo ◽  
Xiaodong Li ◽  
Tinglu Song
Keyword(s):  
Mechanical Properties ◽  
X Ray Diffraction ◽  
Polymeric Chains ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Strain Induced Crystallization ◽  
Thermal Histories ◽  
Static Conditions ◽  
The Relationship ◽  
Induced Crystallization

The relationship between temperature and the mechanical properties of an end cross-linked equal molar random copolyether elastomer of 3,3-bis(azidomethyl)oxetane and tetrahydrofuran (P(BAMO-r-THF)) was investigated. During this investigation, the performances of two P(BAMO-r-THF) elastomers with different thermal histories were compared at different temperatures. The elastomer as prepared at 20 °C (denoted as S0) exhibited semi-crystallization morphology. Wide angle X-ray diffraction analysis indicated that the crystal grains within elastomer S0 result from the crystallization of BAMO micro-blocks embedded in P(BAMO-r-THF) polymeric chains, and the crystallinity is temperature irreversible under static conditions. After undergoing a heating-cooling cycle, this elastomer became an amorphous elastomer (denoted as S1). Regarding mechanical properties, at 20 °C, break strains and stresses of 315 ± 22% and 0.46 ± 0.01 MPa were obtained for elastomer S0; corresponding values of 294 ± 6% and 0.32 ± 0.02 MPa were obtained for elastomer S1. At −40 °C, these strains and stresses simultaneously increased to 1085 ± 21% and 8.90 ± 0.72 MPa (S0) and 1181 ± 25% and 10.23 ± 0.44 MPa (S1), respectively, owing to the strain-induced crystallization of BAMO micro-blocks within the P(BAMO-r-THF) polymeric chains.

Experimental Study of Surface Tension Coefficient for Magnetic Fluid

2011 ◽  
Vol 492 ◽  
pp. 277-282
Author(s):  
Qing Lei Wang ◽  
De Cai Li ◽  
Fan Wang
Keyword(s):  
Surface Tension ◽  
Magnetic Fluid ◽  
Liquid Surface ◽  
Surface Tension Coefficient ◽  
Fluid Surface ◽  
Liquid Surface Tension ◽  
Experimental Apparatus ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
The Relationship

The author measured surface tension coefficient for liquid with a new experimental apparatus, measured magnetic fluid surface tension coefficient at different temperatures and with different volume of surfactant. By the analysis of experimental data, we obtained that magnetic fluid surface tension coefficient decreases with the increasing temperature and increases with the addition of surfactant volume and reaches a certain stability value. We also obtained the expression of magnetic fluid surface tension coefficient and the temperature or surfactant. This paper discussed the relationship between the liquid surface tension coefficient and the temperature and surfactant from the view of thermodynamics.

scholarly journals Mechanical Behaviour of an Al2O3 Dispersion Strengthened γTiAl Alloy Produced by Centrifugal Casting

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1457
Author(s):  
Daniela Pilone ◽  
Giovanni Pulci ◽  
Laura Paglia ◽  
Avishek Mondal ◽  
Francesco Marra ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tial Alloy ◽  
Centrifugal Casting ◽  
Fracture Mechanisms ◽  
Potential Candidate ◽  
Dispersion Strengthening ◽  
Temperature Range ◽  
Structural Applications ◽  
Different Temperatures ◽  
Lower Temperature

γ-TiAl has been a hot topic of research for more than a few decades now, since it is a potential candidate for high temperature structural applications. In this paper, dispersion strengthening of γ based TiAl alloy, produced by means of centrifugal casting, has been performed to increase its mechanical properties beyond those of standard TiAl alloys. After a careful selection of the alloy composition based on the desired properties, several samples were produced by means of investment casting. This work focused on the effect of Al2O3 nano- and micro-dispersoids on the mechanical properties of the considered TiAl alloy. Microstructural investigations were carried out to study both the alloy microstructure and the Al2O3 dispersion homogeneity. Samples of the produced alloy were subjected to four-point bending tests at different temperatures for evaluating the effect of dispersed particles on mechanical properties. The results of this study were promising and showed that Al2O3 dispersion determined an increase of the mechanical properties at high temperatures. The Young’s modulus was 30% higher than that of the reference alloy in the lower temperature range. Over the temperature range 800–950 °C the dispersion strengthening affected the yield stress by increasing its value of about 20% even at 800 °C. A detailed evaluation of fracture surfaces was carried out to investigate fracture mechanisms.

Effect of Temperature and Water Immersion on the Mechanical Properties of Coated Fabrics

2010 ◽  
Vol 129-131 ◽  
pp. 230-234
Author(s):  
Ying Ying Zhang ◽  
Qi Lin Zhang ◽  
Chuan Zhi Zhou ◽  
Ying Zhou
Keyword(s):  
Mechanical Properties ◽  
Water Immersion ◽  
Effect Of Temperature ◽  
C 23 ◽  
Different Temperatures ◽  
Temperature Induction ◽  
Effects Of Temperature ◽  
C 50 ◽  
Coated Fabrics ◽  
Increasing Temperature

As composite, the mechanical properties of coated fabrics are sensitive to environment. This paper presented mechanical properties under different environments. A list of uniaxial tests are carried out under different temperatures including -20°C, 0°C, 23°C, 50°C, and 70°C. First, the tensile behaviors at room temperature and the failure behaviors are studied. Then, the effects of temperature on mechanical properties are determined. Finally, the effects of water immersion on mechanical properties are discussed. Results show PTFE coated fabrics remained unchanged in varying temperature and humidity. The temperature has effects on the mechanical properties of PVC coated fabrics. With increasing temperature, the strength decrease and the strain at break increase. The temperature induction factors are proposed for the design and analysis. The water immersion has little effect on the mechanical properties because of the impervious coating.

NiTi Shape Memory Alloy Wire’s Constitutive Describe at Different Temperatures

2017 ◽  
Vol 729 ◽  
pp. 13-17
Author(s):  
Guang Yong Yang ◽  
Yang Zhong ◽  
Zhi Fei Qiu ◽  
Jun Wang ◽  
Wei Na Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Niti Shape Memory Alloy ◽  
Thermal And Mechanical Properties ◽  
Restoring Force ◽  
Intelligent Material ◽  
Different Temperatures ◽  
Relationship Of ◽  
The Relationship

NiTi shape memory alloy is an intelligent drive and awareness materials which develop very rapidly and is used in many fields in recent years, whose mechanical properties are not only related to chemical composition, but also closely related to the temperature. This article aims to study the NiTi shape memory alloy wire’s constitutive behavior coupled thermal and mechanical properties at different temperatures. By analyzing the results, the relationship of NiTi shape memory alloy between deformation and the restoring force at elevated temperature is obtained, thus providing a basis for the engineering design and simulation process of NiTi intelligent material.

Investigation of Elevated Temperature Mechanical Properties of Intermetallic Compounds in the Cu–Sn System Using Nanoindentation

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Zuozhu Yin ◽  
Fenglian Sun ◽  
Mengjiao Guo
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Elevated Temperature ◽  
Intermetallic Compounds ◽  
Lattice Structure ◽  
Hexagonal Lattice ◽  
Parabolic Law ◽  
Dislocation Movement ◽  
Increasing Temperature ◽  
The Relationship

Abstract In electronic packaging, most researchers are mainly focused on the mechanical properties of Cu–Sn intermetallic compounds (IMCs) at room temperature; few studies have looked into the relationship between hardness, elastic modulus, and plasticity of IMCs and elevated temperature. The hardness, elastic modulus, and plasticity of Cu6Sn5 and Cu3Sn at 25–200 °C are investigated by the nanoindentation method. The results show that the hardnesses of Cu6Sn5 and Cu3Sn obey linear attenuation law with elevated temperature. The hardness of Cu6Sn5 is more sensitive to temperature than that of Cu3Sn. This is due to the fact that the melting point of Cu6Sn5 (415 °C) is lower than that of Cu3Sn (670 °C), Cu6Sn5 has a lower normalization temperature than that of Cu3Sn. The elastic modulus of Cu6Sn5 and Cu3Sn and temperature have a parabolic law at 25–200 °C. The elastic modulus of Cu6Sn5 is more sensitive to temperature. This is attributed to the fact that the lattice structure of Cu6Sn5 is changed from hexagonal lattice to monoclinic lattice, causing its volume to expand, thereby making it more sensitive to temperature. The plasticity factors of Cu6Sn5 and Cu3Sn meet the polynomial relationship with elevated temperature. The plasticity factors of Cu6Sn5 and Cu3Sn increase with increasing temperature, which will reduce the resistance to plastic deformation. This is attributed to the fact that the vacancy generated into the material is conducive to the dislocation movement, the dislocation movement will be more active so that the plasticity factors of Cu6Sn5 and Cu3Sn gradually increase.

Microstructure and Mechanical Properties of Extruded Mg-1.6Gd as Prospective Degradable Implant Materials

2015 ◽  
Vol 1112 ◽  
pp. 462-465 ◽  
Author(s):  
Oknovia Susanti ◽  
Sri Harjanto ◽  
Myrna A. Mochtar
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Microstructure Observation ◽  
Microstructure And Mechanical Properties ◽  
Increasing Temperature ◽  
Relationship Of ◽  
The Relationship ◽  
Peak Value

Mg-1.6 Gd alloy ingot were prepared by hot extrusion. The extruded alloy exhibits the recrystallised grain size and excellent mechanical properties. The aim of this study is to explore the microstructure and mechanical properties of extruded Mg-1.6 Gd to be used as implant. Extrusion was performed at temperatures of 400°C, 450 °C, 500°C and 550°C with a speed of 1mm/s and extrusion ratio of 30%. Tension and hardness testing were carried out on samples taken from extruded rod of Mg-Gd alloy. Microstructure observation revealed that all extruded alloy specimens constitued of finer grain size (~14 um) compared to that of the as-cast alloy (> 500 um) as the result of full recrystallization occured at 400 °C. The grain size increased larger with an increase temperature and the peak value is 25mm at temperature of 550 °C. Hardness of the alloy decreased as the extrusion temperature increased from 48.7 HV at 400 °C to 42 HV at 550 °C which is associated with the change in the grain size. Tensile strengths were not apparently affected by the temperature change, however, it was observed that the tensile and yield strengths dropped at 500 °C. Meanwhile, the elongation decreased with increasing temperature which reached 24 % at the lowest temperature. Detailed explaination of the relationship of microstructure and mechanical properties is discussed in this paper.

scholarly journals Effects of Elevated Temperatures on Mechanical’s concrete specimen behaviour

2018 ◽  
Vol 165 ◽  
pp. 22010
Author(s):  
Nesrine Khodja ◽  
Hadda Hadjab
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Elevated Temperatures ◽  
High Performance Concrete ◽  
Concrete Specimen ◽  
Relative Strength ◽  
Cement Matrix ◽  
Initial Strength ◽  
Different Temperatures ◽  
Increasing Temperature

This paper presents an experimental study on the performance of concrete, subjected to high temperatures. Investigation was carried out by using two mixtures: an Ordinary Concrete (OC) and High Performance Concrete (HPC) with 10% of Silica Fume (SF) replaced of cement weight and 1,5% of super plasticizer, the water-binder (w/b) ratio used was 0,5 and 0,32 respectively. The produced concrete specimens are heated at a rate of 7 °C/min up to different temperatures (150, 300, 450, 600 and 900°C). In order to ensure a uniform temperature through the specimen, the temperature is held constant at the temperature stage for one hour before cooling. Mechanical properties at ambient temperature and residual mechanical properties after heating have already been determined. We examined also the effect of high temperature on the aggregate-cement paste interface and aggregate microstructure of the concrete specimens by scanning electron microscopy (SEM) method to reveal changes occurred after the cycle of heatingcooling. The results revealed that relative strength of the concrete specimens decreased as the exposure temperature increased and reaches about a quarter of its initial strength at 900°C. Moreover SEM examinations showed that, increasing temperature caused weakening of the adherence of aggregate and cement matrix by the appearance of cracks and micro cracks.

scholarly journals Effects of Tantalum on Microstructure Evolution and Mechanical Properties of High-Nb TiAl Alloys Reinforced by Ti2AlC

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Hongze Fang ◽  
Ruirun Chen ◽  
Yong Yang ◽  
Yanqing Su ◽  
Hongsheng Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Influence Factor ◽  
Testing Temperature ◽  
Lattice Parameter ◽  
Major Influence ◽  
Tial Alloys ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
B2 Phase ◽  
The Relationship

Experiments have been carried out to study the relationship between the addition of tantalum and microstructure, especially the formation of the B2 phase in lamellar colonies. The mechanical properties, with different contents of Ta, were also measured. Ti46Al8Nb2.6CxTa alloys were prepared by casting with the content of Ta varying from zero to 1.0 at.%. Experimental results show that the B2 phase forms in lamellar colonies with the addition of Ta, and its content increases when the content of Ta increases. Meanwhile, the γ phase decreases and the lattice parameter of the α2 phase increases. The size of the lamellar colony decreased from 29.9 to 21.6 μm. Ta dissolves into Ti2AlC by substitution, and its solubility is more than 1.1% tested by EDS. Nb, which is necessary for the formation of the B2 phase, comes from two aspects. The first is that Ta dissolves into the Ti2AlC and partly replaces the Nb atom and the second is the decrease in the γ phase because it has higher solid solubility for Nb. The increase in Nb in the liquid phase increases the composition supercooling and heteronucleation at the solidification front, which accounts for refining the lamellar colony. Room temperature compressive testing showed that the compressive strength and the strain increased when the Ta content increased up to 0.8% and then decreased. Improvement of the compressive properties resulted from the grain boundary strengthening and their decrease induced by more content of the B2 phase. Tensile properties, at elevated temperature, were improved with testing temperature increasing from 750 to 950°C, because solid solution strengthening is a major influence factor.

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