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

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.

2007 ◽  
Vol 353-358 ◽  
pp. 1589-1592
Author(s):  
Wen Zhe Chen ◽  
Kai Ping Peng ◽  
Kuang Wu Qian

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.


2015 ◽  
Vol 645-646 ◽  
pp. 926-930 ◽  
Author(s):  
Shuang Shi Yuan ◽  
Guang He ◽  
Ming Zhang ◽  
Guo Zhong Li

MEMS nickel material is commonly used for structural material in micro devices. In order to study the effect of environmental temperature on its mechanical properties,this paper has built up a experimental system which can measure the temperature-related static mechanical parameters of the UV-LIGA nickel material. By using the system for uniaxial tensile experiments of the micro specimen under different temperature, the stress-strain curves of the micro specimen under different temperature were obtained; the mechanical parameters of the micro specimen such as elastic modulus, yield stress and failure stress under different temperature were also calculated out;Finally, the relationship between temperature and mechanical parameters including elastic modulus, yield stress and failure stress was analyzed.


Author(s):  
Z. P. Chow ◽  
Z. Ahmad ◽  
K. J. Wong

This paper presents the effects of elevated temperature on the mechanical response of a glass fibre reinforced epoxy (GFRE) composite. The mechanical properties taken into account are tensile, compression and shear. All tests are carried out at temperatures of 30°C, 70°C and 110°C, below the glass transition temperature of the resin. The properties along fibre direction and perpendicular to fibre direction are investigated, with two sets consisting of 0° and 90° fibre direction for tensile and compression tests. Stress-strain profiles at each temperature are firstly compared. Subsequently, the elastic modulus and the ultimate strength with respect to temperature are assessed. The results indicate that tensile properties remain relatively unaffected at 70°C but drop rapidly at 110°C. In addition, compressive properties decrease steadily from 30°C to 110°C, while shear properties are heavily degraded with increasing temperature. Fibre dominated properties have better heat resistance compared to matrix dominated properties due to matrix softening and weakening. 


2012 ◽  
Vol 198-199 ◽  
pp. 216-219
Author(s):  
Wen Jian Liu ◽  
Quan An Li ◽  
Zhi Chen ◽  
Xiao Jie Song

The microstructure and mechanical properties of aged Mg-5.5Al-1.2Y magnesium alloy with Ca addition are investigated. The results show that with 1.0wt.% Ca addition, the phase of Al2Y is refined obviously and the phase of Mg17Al12 has a dramatic decrease in number. And, high melting point intermetallic compounds Al2Ca and Al4Ca are formed. Meanwhile, the β-Mg17Al12 phase become more dispersed. After 1.0wt.% Ca addition, the mechanical properties of the alloy at room and elevated temperature are improved.


2011 ◽  
Vol 488-489 ◽  
pp. 743-746
Author(s):  
Jiang Tao Yu ◽  
Ke Quan Yu ◽  
Zhou Dao Lu

This paper presents an experimental investigation on the variation of residual fracture toughness of concrete after being exposed to elevated temperatures. A total of 60 specimens, with a uniform size of 200x200x230mm and precast notches of 80mm in height, were heated to constant temperatures of 65°C, 120°C, 200°C, 300°C, 350°C, 400°C, 450°C, 500°C and 600°C respectively. After cooling, standard wedge splitting tests, according to the corresponding Chinese Specification, were employed. The results indicate that the elevated temperature has significant influence on the residual fracture toughness of concrete. The magnitude of fracture toughness decreases drastically with increasing temperature. Additionally the relationship between residual fracture toughness and weight loss of specimens with respect to temperatures is also investigated.


2012 ◽  
Vol 204-208 ◽  
pp. 3799-3804
Author(s):  
Yan Jun Liu ◽  
Mang Tia

This paper investigated the mechanical strength and shrinkage properties of the concrete mixtures frequently used in Florida. The concrete mixtures were proportioned with three different types of coarse aggregates, such as Miami Oolite limestone, Georgia granite and Stalite lightweight aggregate, and two mineral additives, including fly ash and slag. And fourteen concrete mixtures were evaluated on their characteristics of compressive strength, elastic modulus and shrinkage for 91 days. The empirical relationship between the mechanical properties of concretes and shrinkage strain was analyzed mathematically. The results indicate that the compressive strength and elastic modulus of concrete are exponentially related the shrinkage strain of concrete. The finding from this study is agreeable with that by Troxell et al [5]. Also, the effectiveness of ACI 209 and CEB-FIP models on predicting the shrinkage behavior of concretes used frequently in Florida was evaluated. The result indicates that CEB-FIP model gives more reliable prediction than ACI 209 model does.


2007 ◽  
Vol 345-346 ◽  
pp. 653-656 ◽  
Author(s):  
Hyeon Taek Son ◽  
Jae Seol Lee ◽  
Ji Min Hong ◽  
Ik Hyun Oh ◽  
Kyosuke Yoshimi ◽  
...  

The aims of this research are to investigate the effect of Sm addition in Mg-Al-Ca alloys on microstructure and mechanical properties. Sm addition to Mg-5Al-3Ca based alloys results in the change from dendritic to equiaxed grain morphorlogy and formation of Al-Sm rich itermetallic compounds at grain boundary and α-Mg matrix. And these Al-Sm rich intermetallic compounds were dispersed homogeously and stabilized at high temperature. And maximum yield and ultimate strength value was obtained at Mg-5Al-3Ca-2Sm alloys at elevated temperature because of homogeneous dispersion of stable Al-Sm rich intermetallic compound at high temperature.


2013 ◽  
Vol 13 (04) ◽  
pp. 1350057 ◽  
Author(s):  
CHENG-TAO CHANG ◽  
CHOU-CHING K. LIN ◽  
MING-SHAUNG JU

Atomic force microscopy (AFM) has been widely applied to study cellular functions;however, the relationship between cellular elasticity and ultrastructure density of a live cell remains to be discovered. The objective of this study was thus to extend our previous method of integrating AFM and immunofluorescence imaging to measure the ultrastructure distribution-related local mechanical properties of live cells. First, the morphology of a live cell was obtained by AFM. Second, the indentation sites were selected and flexible force volume indentation was performed. Third, the immunofluorescence image of the cell was obtained. The last was the mapping of the indentation site to the immunofluorescence image and obtaining the relationship between the local elastic properties and cytoskeleton density. The results on differentiated rat Schwann cells (RSCs) showed that the elastic modulus of stress fibers is higher than those of the nucleus and cytosol. The local elastic modulus of the live RSCs is correlated to the actin density, and the stress fiber that behaves like a pretension beam can give RSCs enough strength to envelop axons during myelination. In particular, the elastic properties of the live RSCs were twofold lower than those of the fixed. The results demonstrated the integrated method's applicability for a live cell.


2010 ◽  
Vol 97-101 ◽  
pp. 1620-1623 ◽  
Author(s):  
Hong Zhi Cui ◽  
Feng Xing

Many investigations have been conducted on compressive strength of lightweight aggregate concretes (LWAC), but there are few experimental studies on the relationship between compressive strength, bond strength and elastic modulus of LWAC. In this paper, the specimens of twenty kinds of LWACs with different mix proportions were made. Properties of compressive strength, bond strength and modulus of elasticity of the LWACs were tested. Based on the testing resulting, equations for relationship between bond strength and compressive strength of the LWAC were established. For LWAC modulus of elasticity, the experimental results of this study can fit well with predicted equation of ACI 318


2015 ◽  
Vol 1112 ◽  
pp. 462-465 ◽  
Author(s):  
Oknovia Susanti ◽  
Sri Harjanto ◽  
Myrna A. Mochtar

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.


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