Effect of alumina nanoparticles on the microstructure, mechanical, and thermal properties of penta bismuth-tin-based solder alloys

An Al–0.05 vol% nAl2O3 (where nAl2O3 is alumina nanoparticles) composite has been fabricated using accumulative roll bonding with nanoparticle introduction. The microstructure, texture, fracture surfaces, and mechanical properties are investigated using transmission and scanning electron microscopy, electron back scatter diffraction (EBSD), microhardness measurement and tensile tests. The results show that nanoparticle introduction significantly affects the microstructure, texture, and fracture characteristics, but weakly influences the microhardness, strength, and ductility. The possible reasons for the different responses of the studied properties to nanoparticle introduction during accumulative roll bonding are discussed.

In this paper, we investigated the influences of germanium (Ge) addition into Sn-0.7Cu (SC) solder alloy on the microstructure, thermal and mechanical properties by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), differential scanning calorimetry (DSC), universal testing machine and Vickers hardness instrument, respectively. The experiment results showed that the addition of Ge into SC alloy could increase slightly the melting temperature and decrease the undercooling. The pasty range of SC-0.01Ge alloy was reduced by 0.1 °C, compared to that of SC alloy. However, the pasty range of alloy increased obviously when the Ge content in solder alloys was 0.05 or 0.10 wt%. The microstructure of SC-xGe solder alloys were consisted of β-Sn phase and Cu6Sn5 particle. No other intermetallic compounds (IMCs) with Ge content were observed in the solder matrix for SC solder alloys with various Ge content. The tensile properties of the SC-xGe solder alloys, including ultimate tensile strength and elongation, were enhanced gradually with the Ge content increased from 0 to 0.10 pct. This may be due to the presences of Ge and its role in refining microstructure and solid solution strengthening. After aging for 168 h, the ultimate tensile strengths of four solder alloys decreased, which was attributed to the coarsening of Cu6Sn5 particles. But the ductility increased remarkably. This phenomenon could be due to the formation of Sn-rich areas. A comparison of all solder alloys microhardness indicated that the microhardness increased with increasing Ge content. And after aging for 168 h, the microhardness values of four solder alloys decreased by 19%–26%.

This study compares the high-Ag-content Sn-3Ag-0.5Cu with the low- Ag-content Sn-1Ag-0.5Cu solder alloy and the three quaternary solder alloys Sn-1Ag-0.5Cu-0.1Fe, Sn-1Ag-0.5Cu-0.3Fe, and Sn-1Ag-0.5Cu-0.5Fe to understand the beneficial effects of Fe on the microstructural stability, mechanical properties, and thermal behavior of the low-Ag-content Sn-1Ag-0.5Cu solder alloy. The results indicate that the Sn-3Ag-0.5Cu solder alloy possesses small primary β-Sn dendrites and wide interdendritic regions consisting of a large number of fine Ag3Sn intermetallic compound (IMC) particles. However, the Sn-1Ag-0.5Cu solder alloy possesses large primary β-Sn dendrites and narrow interdendritic regions of sparsely distributed Ag3Sn IMC particles. The Fe-bearing SAC105 solder alloys possess large primary β-Sn dendrites and narrow interdendritic regions of sparsely distributed Ag3Sn IMC particles containing a small amount of Fe. Moreover, the addition of Fe leads to the formation of large circular FeSn2 IMC particles located in the interdendritic regions. On the one hand, tensile tests indicate that the elastic modulus, yield strength, and ultimate tensile strength (UTS) increase with increasing Ag content. On the other hand, increasing the Ag content reduces the total elongation. The addition of Fe decreases the elastic modulus, yield strength, and UTS, while the total elongation is still maintained at the Sn-1Ag-0.5Cu level. The effect of aging on the mechanical behavior was studied. After 720 h and 24 h of aging at 100°C and 180°C, respectively, the Sn-1Ag-0.5Cu solder alloy experienced a large degradation in its mechanical properties after both of the aging conditions, whereas the mechanical properties of the Sn-3Ag-0.5Cu solder alloy degraded more dramatically after 24 h of aging at 180°C. However, the Fe-bearing SAC105 solder alloys exhibited only slight changes in their mechanical properties after both aging procedures. The inclusion of Fe in the Ag3Sn IMC particles suppresses their IMC coarsening, which stabilizes the mechanical properties of the Fe-bearing SAC105 solder alloys after aging. The results from differential scanning calorimetry (DSC) tests indicate that the addition of Fe has a negligible effect on the melting behavior. However, the addition of Fe significantly reduces the solidification onset temperature and consequently increases the degree of undercooling. In addition, fracture surface analysis indicates that the addition of Fe to the Sn-1Ag-0.5Cu alloy does not affect the mode of fracture, and all tested alloys exhibited large ductile dimples on the fracture surface.

In this study, we investigated the effects produced by the addition of antimony (Sb) to Sn-3.0Ag-0.5Cu-based solder alloys. Our focus was the alloys’ microstructural, mechanical, and thermal properties. We evaluated the effects by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), differential scanning calorimetry (DSC), and a universal testing machine (UTM). The results showed that a part of the Sb was dissolved in the Sn matrix phase, and the remaining one participated in the formation of intermetallic compounds (IMCs) of Ag3(Sn,Sb) and Cu6(Sn,Sb)5. In the alloy containing the highest wt pct Sb, the added component resulted in the formation of SnSb compound and small particle pinning of Ag3(Sn,Sb) along the grain boundary of the IMCs. Our tests of the Sn-3.0Ag-0.5Cu solder alloys’ mechanical properties showed that the effects produced by the addition of Sb varied as a function of the wt pct Sb content. The ultimate tensile strength (UTS) increased from 29.21 to a maximum value of 40.44 MPa, but the pct elongation (pct EL) decreased from 48.0 to a minimum 25.43 pct. Principally, the alloys containing Sb had higher UTS and lower pct EL than Sb-free solder alloys due to the strengthening effects of solid solution and second-phase dispersion. Thermal analysis showed that the alloys containing Sb had a slightly higher melting point and that the addition amount ranging from 0.5 to 3.0 wt pct Sb did not significantly change the solidus and liquidus temperatures compared with the Sb-free solder alloys. Thus, the optimal concentration of Sb in the alloys was 3.0 wt pct because the microstructure and the ultimate tensile strength of the SAC305 solder alloys were improved.

An experimental study has been conducted on the effect of alumina nanoparticles in a DICI (Direct Injection Compression Ignition) engine using cymbopogon flexuosus (lemongrass oil) as fuel. Lemongrass oil (LGO) is extracted from the steam distillation method. This fuel may also be more suitable for diesel engines as an alternate fuel without any transesterification process and engine modification. In this study, three fuels (LGO25, LGO25+ALU50 ppm and LGO25+ALU100 ppm) were tested in a single-cylinder, four-stroke and naturally aspirated diesel engine. From the experimental analysis, it was found that BSFC decreased with an increase in BTE using alumina nanoparticles. The cylinder pressure and heat release rate are higher by 1.66% at LGO25+ALU 50 ppm and 3.7% at LGO25+ALU 100 ppm than LGO25. In the case of emission study, CO, HC and smoke emissions decreased by 16.67% and 25.79%, 5.9% and 12.83%, and 18.94% and 24.7% at LGO25+ALU50 ppm and LGO25+ALU100 ppm concentrations, respectively. NOx emission is increased by 4.95% and 8.27% for LGO25 with 50 ppm and 100 ppm respectively than LGO25.

The effect of iron and bismuth addition on the microstructural, mechanical, and thermal properties of Sn–1Ag–0.5Cu solder alloy

In this paper, the shape memory, mechanical and Izod impact properties of a new shape memory nanocomposite based on thermoplastic polyurethane (TPU), acrylonitrile butadiene styrene (ABS) and alumina nanoparticles were investigated. The morphological results showed that the presence of 1% alumina nanoparticles made a reduction in diameter of ABS domains and caused a uniform distribution of the ABS phase into the TPU matrix. Surprisingly, the addition of 2 and 3% alumina made the ABS domain larger. We found that this increment in size of droplets can be attributed to the nanoparticle migration into ABS phase in more concentration and agglomeration of nanoparticles which can worsen the compatibility of the blend. In all samples, the tensile strength and impact resistance first increased and then decreased significantly when the content of alumina was more than 1 wt%. Furthermore, the shape memory investigation showed that the shape recovery and fixity of neat TPU/ABS blend improve significantly by presence of alumina nanoparticles. The shape recovery ratio increased from 93.88% for the neat TPU/ABS to 98.99% by loading only 1 wt% nano alumina and, the shape fixity changes from 92.98% to 99.8% by loading 3% alumina nanoparticles.

The addition of Ni on lead-free solder alloys Sn0.7Cu was tested in this study. A small amount of Ni was added to the solder alloys to evaluate the thermal behavior, microstructure, and mechanical properties of the composite solders after sintering and isothermal aging for 3 days and then compared with the results of the binary Sn0.7Cu solder. The results indicated that the ultimate tensile strength and yield tensile strength changed when adding 0.25 wt.% of Ni. The tested results of the differential scanning calorimeter showed that the addition of Ni (such as 0.5 and 1 wt.%) could obviously increase the solidification temperature of Sn0.7Cu alloys in the cooling process. When the Ni content was increased to 0.25 wt.% in the ternary condition, which includes the Sn0.7Cu-xNi (x = 0, 0.1, 0.25, 0.5, and 1 wt.%) solder alloys for the indentation creep test, the minimum creep rate reached the maximum; however, the trend was reversed as the Ni content was higher than this level. In addition, the microstructure of Sn-0.7Cu-xNi solder alloys was obviously different with the eutectic Sn-0.7Cu solder, such that the Ni gradually accumulated in the (Cu, Ni)6Sn5 IMCs within the Ni-containing solder alloys. Additionally, this process refined the microstructure of the Sn-0.7Cu solder. The fracture surface of the eutectic Sn-0.7Cu solder revealed ductile fracture modes; however, there was no mixed ductile–brittle fracture mode occurred when the Ni content was in the range of 0-1 wt.%.

Nano scale dispersion due to the size transformation of the reinforced particles from micron size to nano size in the polymer matrix to enhance the mechanical properties of fiber-reinforced hybrid composite is an interesting research topic of the current time. In this study, the nanocomposites test coupons were prepared through the open molding route. The nano scale dispersion is achieved at an optimum concentration of alumina particles (2 wt%), which results in improved thermal stability, impact strength, flexural modulus and flexural strength of composites. The maximum enhancement in impact energy was observed to be 84 % correspond to the addition of 2 wt%, 20 % for the flexural strength correspond to the addition of 3 wt% and 35 % for the flexural modulus correspond to the addition of 5 wt% alumina particles to the epoxy matrix. For the addition of 5 wt% of short glass/carbon fibers to the epoxy, an improvement of 130 % and 170 % for the flexural strength and 55 % and 95 % for the flexural modulus was observed. Furthermore, addition of optimum concentration (i.e. 2 wt%) of alumina nano particle to the 5 wt% glass/carbon fiber reinforced hybrid composites resulted in the improvement of impact properties, flexural strength and flexural modulus of 175 %, 195 %; 18 %, 26 % and 65 %, 85 % as compared to the neat epoxy, and 7 %, 8 %; 82 %, 105 % and 17 %, 5 % as compared to the short fiber reinforced composites. These enhancements in the mechanical properties are mainly due to the better stress transfer properties from fiber and nanoparticle to the matrix, due to the existence of strong interfacial interactions between both epoxy/alumina nanoparticles, which depict the higher resistance to fiber pull out as compare to fiber reinforced composites without alumina nanoparticles.

Sn-Cu based solders have been widely investigated due to their good mechanical properties, good fluidity, narrow melting range, environmental friendliness, and low price. In this paper, the effect of Ni content on the microstructure, mechanical properties, melting behavior, spreadability, and conductivity of Sn-0.7 Cu-xNi (0.5-2.0 mass%, mass fraction except when specified) lead-free solders was studied. The Sn-0.7Cu-xNi (x = 0.5, 1.0, 1.5, and 2.0) solder alloys consisted of a β-Sn solid solution, Ni3Sn4 phase, and Cu6Sn5 phase. The volume fraction of Ni3Sn4 increased with increasing Ni content. The addition of Ni increased the solidus and liquidus temperatures of the Sn-0.7Cu-xNi solder alloys. However, the melting range of the Sn-0.7Cu-0.5Ni and Sn-0.7Cu-1.0Ni solder alloys is lower than that of the Sn-0.5Cu solder alloy. The spreading area of the Sn-0.7Cu-xNi solder alloy first increased and then decreased with increasing Ni content. Moreover, the ultimate tensile strength and hardness of the Sn-0.7Cu-xNi solder alloy increased gradually with increasing Ni content. The Sn-0.7Cu-2.0Ni alloy has maximum ultimate tensile strength and hardness values of 52.01 MPa and 16.45 Hv, respectively. However, the electrical conductivity of the Sn-0.7Cu-xNi solder alloy decreased with increasing Ni content. These changes in performance related to the formation of the intermetallic Ni3Sn4 phase. The Sn-0.7Cu-1.0Ni solder alloy had the best comprehensive performance in the present experiment. For the Sn-0.7Cu-1.0Ni solder alloy, the expanded area was 1.28 times that of the Sn-0.7Cu alloy, and the liquidus temperature, melting range, strength, hardness, and resistivity of the alloy solder were at the intermediate level among the Sn-0.7Cu-xNi solder alloys. Therefore, the Sn-0.7Cu-1.0Ni alloy is a relatively ideal solder alloy with a good comprehensive performance among the Sn-0.7Cu-xNi solder alloys.

PurposeThis study aims to investigate the impact of indium (In) content on the thermal properties, microstructure and mechanical properties of Sn-3Ag-3Sb-xIn (x = 0, 1, 2, 3, 4, 5 Wt.%) solders to enhance the performance of tin-based solder under demanding conditions and to meet the urgent need for high-reliability microelectronic interconnection materials in emerging sectors such as automotive intelligent technology, 5G communication technology and high-performance computing.Design/methodology/approachIn this study, Sn-3Ag-3Sb-xIn solder alloys were prepared. The thermal properties of the solder alloys were characterised by differential scanning calorimetry. Subsequently, optical microscopy, scanning electron microscopy, X-ray diffraction and an electron probe X-ray microanalyser were used to analyse the influence of the In content on the microstructure of the solder. The mechanical properties of solder alloys were determined through tensile testing.FindingsAs the In content increased, the melting temperature of the Sn-3Ag-3Sb-xIn solder decreased, accompanied by less nucleation undercooling and an expanded melting range. The incorporation of In led to an enhancement in the yield and tensile strengths of the Sn-3Ag-3Sb-xIn solder alloys, but with a concomitant decrease in plasticity. In comparison to commercial Sn-3.0Ag-0.5Cu solder alloys, the yield strength and tensile strength of the Sn-3Ag-3Sb-3In alloy increased by 8.64 and 21.69 MPa, respectively, while the elongation decreased by 11.48%.Originality/valueSn-3Ag-3Sb-3In solder alloy was the most appropriate and expected comprehensive properties. The enhancements will provide substantial assistance and precise data references for the interconnection requirements in high-strength interconnection fields, such as automotive intelligent technology, 5G communication technology and high-performance computing.

In this research, we investigated the influence of indium and antimony additions on the microstructure, mechanical and thermal properties of Sn-3.0Ag-0.5Cu lead free solder alloys. The results revealed that the addition of 0.5 wt.%InSb into SAC305 solder alloys resulted to a reduced melting temperature by 3.8 °C and IMCs phases formed new Ag3(Sn,In) and SnSb in the Sn-rich matrix with a decreased grain size of 28%. These phases improved the mechanical properties of solder alloys. In addition, the mechanical properties of SAC305 solder alloys increased by adding 0.5 wt.%InSb, resulting in an increase of ultimate tensile strength of 24%, but the percent elongation decreased to 45.8%. Furthermore, the Vickers microhardness slightly increased of the SAC305 solder alloys.

Influence of Fe and Ho additions on Sn-3.0Ag-0.5Cu solder alloy: Microstructure, electrochemical and mechanical properties

Effects of alumina nanoparticles on the microstructure, strength and wear resistance of poly(methyl methacrylate)-based nanocomposites prepared by friction stir processing.

Reinforcement materials such as carbon nanotubes (CNTs), have been demonstrated to be beneficial in improving composite-solder reliability through their super electrical, mechanical and thermal properties. However, interfacial interaction weakness still exists between CNTs and solder alloys. In this study, we managed to incorporate nickel-coated multi-walled carbon nanotubes (Ni-CNTs) into Sn3.0Ag0.5Cu solder matrix with various weight percentages of 0.01 wt%, 0.05 wt%, and 0.1 wt%. Microstructures, intermetallic compound (IMC) layers, mechanical properties including micro-hardness and shear testing, have been implemented to investigate the solderability of composite solders with the utilization of scanning electron microscope and energy dispersive X-ray spectrometer analysis. In comparison with Ni-CNT doping method, CNT doping is easily getting saturated and hereafter arduously to be incorporated due to their physical and chemical limitations. With 0.05 wt% doping Ni-CNTs, fine Ag <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Sn strips and scallop-shaped (Cu, Ni) <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> Sn <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf> IMC layer are formed at the solder-subtract interface, resulting in the maximum improvement of 24.3% and 14.9% in hardness and shear strength, respectively. The existence of micro dopants in the composite solder act as impurity centers and can effectively retard the diffusion of atoms. The increase in strengthening effects in solder joints can be attributed to the combination of (a) impeding effects of uniformly distributed second-phase particles and (b) the consumption of Ni by intermetallic reactions.