Microstructure and Mechanical Properties of TiNiFe Shape Memory Alloys with Different Compositions

2016 ◽  
Vol 849 ◽  
pp. 295-301 ◽  
Author(s):  
Yan Feng Li ◽  
Xue Feng ◽  
Xun Jun Mi ◽  
Xiang Qian Yin ◽  
Xiao Yu Kang

The microstructure and mechanical properties of TiNiFe alloys with different compositions was investigated by tensile test, X-ray diffraction, EBSD, SEM, and TEM. The results indicated that tensile strength rapidly increased with increasing Ni content. In addition, Ti2(Ni,Fe) particles were observed in the TiNiFe alloys, which affected the mechanical properties. Increasing the content of Ni had little influence on the grain size of TiNiFe alloys. With the replacement of Ni by Fe, the lattice constant of TiNiFe alloys decreased as the Ni content increased.

2011 ◽  
Vol 704-705 ◽  
pp. 1095-1099
Author(s):  
Peng Liu ◽  
Hao Ran Geng ◽  
Zhen Qing Wang ◽  
Jian Rong Zhu ◽  
Fu Sen Pan ◽  
...  

Effects of AlN addition on the microstructure and mechanical properties of as-cast Mg-Al-Zn magnesium alloy were investigated using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile testing. Five different samples were made with different amounts of AlN(0wt%, 0.12wt%, 0.30wt%, 0.48wt%, 0. 60wt%). The results show that the phases of as-cast alloy are composed of α-Mg,β-Mg17Al12. The addition of AlN suppressed the precipitation of the β-phase. And, with the increase of AlN content, the microstructure of β-phase was changed from the reticulum to fine grains. When AlN content was up to 0.48wt% in the alloy, the β-phase became most uniform distribution. After adding 0.3wt% AlN to Al-Mg-Zn alloy, the average alloy grain size reduced from 102μm to 35μm ,the tensile strength of alloy was the highest. The average tensile strength increased from 139MPa to 169.91MPa, the hardness increased from 77.7HB to 98.4HB, but the elongation changes indistinctively. However, when more amount of AlN was added, the average alloy grain size did not reduce sequentially and increased to 50μm by adding 0.6wt% AlN and the β-phase became a little more. Keywords: Al-Mg-Zn alloy; AlN; β-Mg17Al12; Tensile strength


2012 ◽  
Vol 516-517 ◽  
pp. 1902-1905 ◽  
Author(s):  
Abd Rashid Amirul ◽  
Yusoff Mahani

Copper alloy C194 lead frame occasionally has been observed creates non-sticking defect at wire bond process in typical microelectronic assembly line. The effect was significantly assessed as process variation during die attach. In this study, microstructure and mechanical properties of copper alloy lead frames were investigated. The copper alloy lead frames were selected from different batches in the production line that produced sticking (typical performance) and non-sticking defect. The micro structural and structural properties were investigated by means of optical microscopy (OM) and X-ray diffraction (XRD), respectively. The hardness and tensile strength were also determined. The result revealed that non-sticking lead frame has larger grain size of 43.8 nm than typical performance lead frame. Due to lower dislocation density, tensile strength and hardness of typical lead frame with smaller grain size were higher than that of defect lead frame. Elongation of defect lead frame was reached above 10% as compared to typical performance lead frame groups with the value below 4%.


2019 ◽  
Vol 54 (6) ◽  
pp. 765-772 ◽  
Author(s):  
Ajay Kumar Vemulapalli ◽  
Rama Murty Raju Penmetsa ◽  
Ramanaiah Nallu ◽  
Rajesh Siriyala

Hydroxyapatite is a very attractive material for artificial implants and human tissue restorations because they accelerate bone growth around the implant. The hydroxyapatite nanocomposites (HAp/TiO2) were produced by using high energy ball milling. X-ray diffraction studies revealed the formation of HAp and TiO2 composites. Cubic-like crystals with boundary morphologies were observed; it was also found that the grain size gradually increased with the increase in TiO2 content. It was found that the mechanical properties (hardness, Young's modulus, fracture toughness, flexural strength, and compression strength)of the composites significantly improved with the addition of TiO2, which was sintered at 1200℃. These properties were then also correlated with the microstructure of the composites. This paper investigates the effect of titania (TiO2 = 0, 5, 10, 15, 20, and 25 wt%) addition on the microstructure and mechanical properties of hydroxyapatite (Ca10(PO4)6(OH)2) nanocomposites.


2021 ◽  
Vol 15 (2) ◽  
pp. 7983-7992
Author(s):  
Oswaldo Rivero ◽  
Diego Pico ◽  
Laura G Castruita ◽  
Francisco García-Pastor ◽  
Jimy Unfried

In this work the microstructure, texture and mechanical properties during different stages of reverse cold rolling (RCR) process on aluminium alloy AA1100-H14 were analysed.  Microstructure was observed using optical and electron scanning microscopy. Texture was analysed using X-ray diffraction (macrotexture) and electron back-scattering diffraction (microtexture) techniques. Tensile test and microhardness measurements were carried out. Results showed that a high deformation using RCR was obtained in samples of annealed state leading to maximum values of tensile strength and hardness, along with a reduction of ductility. Intensity of -fibres decreased producing unstable textures {112} <110> while microstructure exhibited refinement of grain, with enlarged morphology.


2011 ◽  
Vol 194-196 ◽  
pp. 1374-1377
Author(s):  
Chang Qing Li ◽  
Quan an Li ◽  
Xing Yuan Zhang ◽  
Qing Zhang

The microstructure and mechanical properties of aged Mg-5.5Al-1.2Y magnesium alloy with Sb addition are investigated by optical microscope, SEM and X-ray diffraction analyzer. The results show that with proper content of Sb addition,the microstructure of Mg-5.5Al-1.2Y magnesium alloy is refined obviously and high melting point intermetallic compounds Sb3Y5 and Mg3Sb2 are formed. Meanwhile, the β-Mg17Al12 phase is more distributed. With the increase of Sb addition, the mechanical properties of the alloy at room and elevated temperature increase at first, and then decrease. When the content of Sb is up to 0.5%, the values of tensile strength and elongation at room temperature, 150ºC and 175ºC are up to their maxima synchronously, 241MPa /16.84%, 198MPa/20.27.86% and 169MPa/21.21% respectively.


2017 ◽  
Vol 898 ◽  
pp. 638-642 ◽  
Author(s):  
Dong Xu Qiao ◽  
Hui Jiang ◽  
Xiao Xue Chang ◽  
Yi Ping Lu ◽  
Ting Ju Li

A series of refractory high-entropy alloys VTaTiMoAlx with x=0,0.2,0.6,1.0 were designed and produced by vacuum arc melting. The effect of added Al elements on the microstructure and mechanical properties of refractory high-entropy alloys were investigated. The X-ray diffraction results showed that all the high-entropy alloys consist of simple BCC solid solution. SEM indicated that the microstructure of VTaTiMoAlx changes from equiaxial dendritic-like structure to typical dendrite structure with the addition of Al element. The composition of different regions in the alloys are obtained by energy dispersive spectroscopy and shows that Ta, Mo elements are enriched in the dendrite areas, and Al, Ti, V are enriched in inter-dendrite areas. The yield strength and compress strain reach maximum (σ0.2=1221MPa, ε=9.91%) at x=0, and decrease with the addition of Al element at room temperature. Vickers hardness of the alloys improves as the Al addition.


2010 ◽  
Vol 667-669 ◽  
pp. 457-461
Author(s):  
Wei Guo ◽  
Qu Dong Wang ◽  
Man Ping Liu ◽  
Tao Peng ◽  
Xin Tao Liu ◽  
...  

Cyclic channel die compression (CCDC) of AZ31-1.7 wt.% Si alloy was performed up to 5 passes at 623 K in order to investigate the microstructure and mechanical properties of compressed alloys. The results show that multi-pass CCDC is very effective to refine the matrix grain and Mg2Si phases. After the alloy is processed for 5 passes, the mean grain size decreases from 300 μm of as-cast to 8 μm. Both dendritic and Chinese script type Mg2Si phases break into small polygonal pieces and distribute uniformly in the matrix. The tensile strength increases prominently from 118 MPa to 216 MPa, whereas the hardness of alloy deformed 5 passes only increase by 8.4% compared with as-cast state.


2020 ◽  
Vol 405 ◽  
pp. 379-384
Author(s):  
Joanna Borowiecka-Jamrozek ◽  
Jan Lachowski

The main purpose of this work was to determine the effect of the powder composition on the microstructure and properties of iron-based sinters used as a matrix in diamond tools. The Fe-Cu-Ni sinters obtained from a mixture of ground powders were used for experiments. The influence of manufacturing process parameters on the microstructure and mechanical properties of sinters was investigated. Sintering was performed using hot-pressing technique in a graphite mould. The investigations of obtained sinters included: density, hardness, static tensile test, X-ray diffraction analysis, microstructure and fracture surface observations. The obtained results indicate that the produced sinters have good plasticity and relatively high hardness.


2018 ◽  
Vol 89 (9) ◽  
pp. 1770-1781 ◽  
Author(s):  
Huaizhong Xu ◽  
Benedict Bauer ◽  
Masaki Yamamoto ◽  
Hideki Yamane

A facile route was proposed to fabricate core–sheath microfibers, and the relationships among processing parameters, crystalline structures and the mechanical properties were investigated. The compression molded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH)/poly(L-lactic acid) (PLLA) strip enhanced the spinnability of PHBH and the mechanical properties of PLLA as well. The core–sheath ratio of the fibers was determined by the prefab strip, while the PLLA sheath component did not completely cover the PHBH core component due to the weak interfacial tension between the melts of PHBH and PLLA. A rotational target was applied to collect aligned fibers, which were further drawn in a water bath. The tensile strength and the modulus of as-spun and drawn fibers increased with increasing the take-up velocities. When the take-up velocity was above 500 m/min, the jet became unstable and started to break up at the tip of the Taylor cone, decreasing the mechanical properties of the fibers. The drawing process facilitated the crystallization of PLLA and PHBH, and the tensile strength and the modulus increased linearly with the increasing the draw ratio. The crystal information displayed from wide-angle X-ray diffraction patterns and differential scanning calorimetry heating curves supported the results of the tensile tests.


2017 ◽  
Vol 898 ◽  
pp. 124-130 ◽  
Author(s):  
Shu Min Xu ◽  
Xin Ying Teng ◽  
Xing Jing Ge ◽  
Jin Yang Zhang

In this paper, the microstructure and mechanical properties of the as-cast and heat treatment of Mg-Zn-Nd alloy was investigated. The alloy was manufactured by a conventional casting method, and then subjected to a heat treatment. The results showed that the microstructure of as-cast alloy was comprised of α-Mg matrix and Mg12Nd phase. With increase of Nd content, the grain size gradually decreased from 25.38 μm to 9.82 μm. The ultimate tensile strength and elongation at room temperature of the Mg94Zn2Nd4 alloy can be reached to 219.63 MPa and 5.31%. After heat treatment, part of the second phase dissolved into the magnesium matrix and the grain size became a little larger than that of the as-cast. The ultimate tensile strength was declined by about 2.5%, and the elongation was increased to 5.47%.


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