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The effects of copper organic solderability preservative (Cu-OSP) and electroless nickel immersion gold (ENIG) surface finish reflowed on Sn-3.0Ag-0.5Cu (SAC305) solder have been investigated in detail. Besides conventional cross-sectional microstructure observation, advanced characterization techniques such as synchrotron radiography imaging and synchrotron micro-x-ray fluorescence (µ-XRF) were utilized to elucidate the microstructural evolution in the solder joints during soldering. Additionally, high-speed shear testing was performed to understand the influence of the surface finish on the solder joint strength. The results indicated that the presence of nickel (Ni) from the ENIG surface finish decreased the growth rate but increased the amount of small Cu6Sn5 primary intermetallics, resulting in a slight reduction of the average interfacial intermetallic compound (IMC) thickness in the SAC305/ENIG solder joints. Due to the refined control of the solder joint microstructure, the average high-speed shear strength was higher for as-reflowed SAC305/ENIG versus SAC305/Cu-OSP solder joints. These results indicate a significant influence of the surface finish on SAC305 solder joint microstructure and strength and could provide a basis to improve solder joint strength.

Kaolin has an excellent structure formed via a wide range of firing temperature. The correlation between the mineralogy and reactivity of individual elements is extremely complex in a sintered geopolymer material. The main objective of this work is to elucidate the influence of the chemical composition of the raw materials used post-sintering on the kaolin-ground granulated blast furnace slag (GGBS) geopolymer. The samples were cured at room temperature for 5 days before being sintered. The ratio of solid-to-liquid were 1:1, 1.5:1, and 2:1. The addition of the GGBS to the kaolin geopolymer slurry did not only hasten the hardening process during geopolymerization, the presence of SiO2, Al2O3, CaO, and MgO in GGBS had accelerated the formation of nepheline, gehlenite, akermanite, and albite phase after sintering based on the result from x-ray diffraction and fourier-transform infrared spectroscopy On top of the phase transformation, a high ratio of solid-to-liquid (SL 2) had improved the pore distribution from irregular size to well defined formation and increased the densification of the sintered materials. Elemental distribution from micro-XRF investigation prove the high concentration of Ca in localized area and uniformly distribution of Si aligned with the phase of akermanite in SL 2. The main chemical composition of kaolin and GGBS which are SiO2, Al2O3, CaO and MgO had contributed in phase transformation of sintered kaolin-GGBS geopolymer.

This study examines factor(s) behind the formation of primary Cu6Sn5 (in the bulk, rather than at the interface) in solder joints, even though solder alloys are hypoeutectic. To understand the contribution from copper (Cu) dissolution from the substrate a Cu-free alloy, tin-3.5 silver (Sn-3.5Ag), was used as a soldered-on copper organic solderability preservative (Cu-OSP) and electroless nickel immersion gold (ENIG) surface finish substrates. Microstructure observations including in situ synchrotron were used to observe microstructure development real-time and confirm the time and location for nucleation of primary Cu6Sn5. High-speed shear tests were performed to determine the solder joint’s strengths. The results confirm that Cu dissolution during soldering is responsible for the formation of primary Cu6Sn5. The ENIG finish prevented Cu dissolution and the formation of Cu6Sn5 resulting in higher solder joint strength for the Sn-3.5Ag/ENIG solder joints. The findings can be used to understand the evolution of primary Cu6Sn5 and how it can be suppressed to improve joint strength.

The investigation on tin (Sn) whiskers formation has been widely applied in the field of lead-free electronic packaging. This is due to the fact that use of the Sn–Pb finishes has converted to Pb-free finishes in the electronic industry. Sn whiskers can grow long enough to cause a short circuit, which affects electronic devices’ reliability. This study investigates Sn whiskers’ formation in the thin Sn–0.7Cu–0.05Ga Pb-free solder under the influence of electromigration and thermal ageing for surface finish applications. The samples were stored in ambient conditions for 1000 h before being exposed to electromigration and thermal ageing to study the corresponding whiskers’ growth. A scanning electron microscope (SEM) was used to study the Sn whiskers’ microstructure, while an optical microscope (OM) was utilized to investigate the IMC layers in the samples. The results show that the addition of 0.05 wt.% gallium (Ga) decreased the Sn whisker’s length and growth density while simultaneously refining the IMC layers. Synchrotron micro-XRF (µ-XRF) shows the existence and distribution of Ga addition in both electromigration and thermal ageing samples. The shear test was used to determine the solder alloys’ mechanical properties. As a result, the addition of Ga to the Sn–0.7Cu solder improved the fracture morphology of solder joints. In conclusion, Ga’s addition resulted in decreasing Sn whisker formation and refining of the IMCs while also increasing the shear strength of the Sn–0.7Cu solder by ~14%.

The present investigation explores the influence of Ni and Bi on the solderability of Sn-0.7Cu solder coatings. The minor addition of 0.05 wt.% Ni into the Sn-0.7Cu solder alloy results in an improvement in the wettability based on dipping tests. The solderability investigation using a globule mode shows the influence of Ni and Bi on the interfacial intermetallic compound (IMC). The addition of Ni to a Sn-0.7Cu solder coating resulted in a (Cu,Ni)6Sn5 interfacial IMC, which enhanced the solderability performance during the globule test. With an increasing amount of Bi in the Sn-0.7Cu-0.05Ni-xBi solder ball, the surface energy of the solder alloy can be reduced, and this improves the solderability. The synchrotron micro-XRF results indicate that Ni is found in a relatively high concentration in the interfacial layer. Additionally, Bi was found to be homogenously distributed in the bulk solder, which improved solderability.

The corrosion resistance of materials composed of metal is an essential property for preventing material deterioration caused by corrosion. In this study, we demonstrate that corrosion resistance can be significantly improved through the electrodeposition of molybdenum oxide onto a metal plating containing iron-group elements. Mo oxide can be electrodeposited using a simple plating bath, low current density, and short deposition time, exhibiting a fascinating metallic gloss appearance. GI-XRD and XPS analyses revealed that amorphous Mo oxide adhered to the substrate by a seed layer partially reduced to metallic Mo by the iron-group element in the substrate, based on the principle of “induced co-deposition.” A Mo oxide coating with a thickness of approximately 100 nm decreases the corrosion current density of Ni-W plating by approximately 5 times and the passivation current density by approximately 10 times in a 3 mass% NaCl solution. Mo oxide coatings represent an attractive strategy for improving the corrosion resistance of various metal materials containing iron-group elements.

This paper clarified the microstructural element distribution and electrical conductivity changes of kaolin, fly ash, and slag geopolymer at 900 °C. The surface microstructure analysis showed the development in surface densification within the geopolymer when in contact with sintering temperature. It was found that the electrical conductivity was majorly influenced by the existence of the crystalline phase within the geopolymer sample. The highest electrical conductivity (8.3 × 10−4 Ωm−1) was delivered by slag geopolymer due to the crystalline mineral of gehlenite (3Ca2Al2SiO7). Using synchrotron radiation X-ray fluorescence, the high concentration Ca boundaries revealed the appearance of gehlenite crystallisation, which was believed to contribute to development of denser microstructure and electrical conductivity.

The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm−1 becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.

A geopolymer has been reckoned as a rising technology with huge potential for application across the globe. Dolomite refers to a material that can be used raw in producing geopolymers. Nevertheless, dolomite has slow strength development due to its low reactivity as a geopolymer. In this study, dolomite/fly ash (DFA) geopolymer composites were produced with dolomite, fly ash, sodium hydroxide, and liquid sodium silicate. A compression test was carried out on DFA geopolymers to determine the strength of the composite, while a synchrotron Micro-Xray Fluorescence (Micro-XRF) test was performed to assess the elemental distribution in the geopolymer composite. The temperature applied in this study generated promising properties of DFA geopolymers, especially in strength, which displayed increments up to 74.48 MPa as the optimum value. Heat seemed to enhance the strength development of DFA geopolymer composites. The elemental distribution analysis revealed exceptional outcomes for the composites, particularly exposure up to 400 &deg, C, which signified the homogeneity of the DFA composites. Temperatures exceeding 400 &deg, C accelerated the strength development, thus increasing the strength of the DFA composites. This appears to be unique because the strength of ordinary Portland Cement (OPC) and other geopolymers composed of other raw materials is typically either maintained or decreases due to increased heat.

This paper elucidated the microstructural and porosity evolution of alkali activated slag at 800 °C up to 1200 °C. The microstructural analysis obtained shows the changes in surface densification of glassy phase and nucleation of dynamical grains within the alkali activated slag when in contact with high heating temperature. Using synchrotron radiation X-ray tomographic microscopy, the number of pores in alkali activated slag decreased with increasing heating temperature. The 3D pores distribution also demonstrated significant increase in the range size of ~20 μm with the appearance of isolated and intergranular pores at 1200 °C. These changes also led to the anorthite crystallisation indicated by high angle grain boundaries and preferred crystal orientation. The evolution of porosity and crystalline phase is contributed to the development of internal strain after heating at high temperature environment.

This paper elucidated the effects of the Bi element (0 wt%, 0.5 wt% and 1.5 wt%) on the microstructure, electrical, wettability and mechanical properties of the Sn-0.7Cu-0.05Ni as a high strength solder. Besides using the conventional cross-sectioned microstructure image, the real-time synchrotron radiation imaging and synchrotron micro-X-ray fluorescence (XRF) technique was also used to investigate the microstructure, focusing on the in-situ growth behaviour of the primary (Cu,Ni)6Sn5 intermetallic and elemental distribution that had occurred in the Sn-0.7Cu-0.05Ni-1.5Bi. Other essential properties of solder material, such as wettability, electrical resistance, and shear strength, were also determined. The results showed that the addition of 1.5 wt% Bi refined the primary (Cu,Ni)6Sn5 intermetallics formation in the solder joint, where it grew earlier and faster relative to that in the Sn-0.7Cu-0.05Ni/Cu joint. Additionally, the addition of 1.5 wt% Bi resulted with a 3% reduction of its electrical resistance while increasing the wettability of the solder alloy. 1.5 wt% addition of the Bi element also found to have contributed to a significant increment of shear strength relative to that of the Sn-0.7Cu-0.05Ni. The results confirmed that the developed material is applicable as a potential high strength solder material in the context of advanced interconnecting applications. Keywords: Soldering, Solder, Interconnects, Intermetallics, Solid solution, Microstructure, Solder properties

This paper elucidates the fabrication of kaolin geopolymer as the ceramic material. The kaolin geopolymer ceramic (KGC) was used as a new potential reinforcement in the lead-free solder. The fabrication of KGC was started through combination of alkaline solution of NaOH and Na2SiO3 reaction with kaolin material. The mixture of kaolin geopolymer were prepared and the homogenised mixture were curing for 24 hours. The kaolin geopolymer is sintered at 1200°C and then crushed to produces a fine kaolin geopolymer. The KGC were then mixed with lead-free solder through powder metallurgy technique. The elemental distribution in the KGC was investigated by using Synchrotron Micro-XRF. Meanwhile, the phase analysis involved in KGC and composite solder with addition of KGC were investigated as well.

This manuscript reports the isothermal annealing effect on the mechanical and microstructure characteristics of Sn-0.7Cu-1.5Bi solder joints. A detailed microstructure observation was carried out, including measuring the activation energy of the intermetallic compound (IMC) layer of the solder joints. Additionally, the synchrotron µX-ray fluorescence (XRF) method was adopted to precisely explore the elemental distribution in the joints. Results indicated that the Cu6Sn5 and Cu3Sn intermetallic layers thickness at the solder/Cu interface rises with annealing time at a rate of 0.042 µm/h for Sn-0.7Cu and 0.037 µm/h for Sn-0.7Cu-1.5Bi. The IMC growth’s activation energy during annealing is 48.96 kJ mol-1 for Sn-0.7Cu, while adding Bi into Sn-0.7Cu solder increased the activation energy to 55.76 kJ mol−1. The µ-XRF shows a lower Cu concentration level in Sn-0.7Cu-1.5Bi, where the Bi element was well dispersed in the β-Sn area as a result of the solid solution mechanism. The shape of the IMC layer also reconstructs from a scallop shape to a planar shape after the annealing process. The Sn-0.7Cu hardness and shear strength increased significantly with 1.5 wt.% Bi addition in reflowed and after isothermal annealing conditions.

A nondestructive testing, Micro-X-ray Fluorescence (µ-XRF) was applied in this work to image the element distribution of slag geopolymers. The µ-XRF map reveal the Al, Si, and Ca chemical spatial on the samples. The details of samples preparation and micro-XRF setting used were discussed in this paper. The bulk XRF and micro-XRF results of slag geopolymers are comparable.A nondestructive testing, Micro-X-ray Fluorescence (µ-XRF) was applied in this work to image the element distribution of slag geopolymers. The µ-XRF map reveal the Al, Si, and Ca chemical spatial on the samples. The details of samples preparation and micro-XRF setting used were discussed in this paper. The bulk XRF and micro-XRF results of slag geopolymers are comparable.

As sessile organisms, plants must constantly adapt to environmental changes. Plant performance is related to availability of light, water, and mineral nutrients, which is especially important in agricultural systems, where minerals are removed from the fields at harvest. Mineral nutrients are also essential for the normal functioning of animal and human body. Since plants are world’s primary producers representing the basis for animal and human diet, it is of extreme importance that they contain sufficient amounts of mineral nutrients and low amounts of antinutrients and noxious elements. To maintain homeostasis with optimal cell functioning and integrity, proper allocation of elements at organ, tissue, cellular, and subcellular level is essential. Studies of element localization are therefore crucial to uncover the mechanisms of element transport and accumulation, toxicity, and tolerance. In the last two decades, a remarkable progress has been made in the development and application of different 2D imaging techniques in complex biological systems, especially with regard to improved lateral resolution and sensitivity as well as sample preparation. In this chapter, the latest development and applications of focused beam techniques like microparticle-induced X-ray emission (μ-PIXE), micro-X-ray fluorescence spectrometry (μ-XRF), and laser ablation inductively coupled plasma-mass spectrometry (LA-ICPMS) in imaging the distributions of major and trace elements in plants are presented. These techniques are unique in providing in situ information and, with appropriate sample preparation, provide results true to biological condition of the living plants. For example the methods for sampling and sample preparation can in conjunction with measurement conditions compromise the element distribution: critical consideration is therefore required when reporting “in vivo” elemental distribution and concentration.

The main objective in this study is to elucidate the geopolymerization of Class C fly ash at different solid-to-liquid ratio (1.0-3.0) by using heat evolution analysis. Differential Scanning Calorimeter was used to monitor heat evolution. The calculated heat evolved was utilized to analyze the reaction kinetics using Johnson-Mehl-Avrami-Kolmogrov Model and correlate with the compressive strength and microstructural properties encompassing morphology, functional group, phase analysis, and elemental distribution. The heat evolution was found to increase with increasing solid-to-liquid ratios. The nucleation mechanism of geopolymerization of Class C fly ash was governed by instantaneous heterogeneous nucleation with rod-like growth. Solid-to-liquid ratio of 2.5 was concluded as optimal ratio due to its great performance for strength development. Meanwhile the contribution of calcium (Ca) and iron (Fe) was confirmed due to the presence of Si-O-Ca and Si-O-Fe bonds in the functional group analysis, which was further confirmed by phase analysis and elemental distribution mapping.

This paper investigates the strength development of solely ground granulated blast furnace slag geopolymers (GGBFS). An optimal combination of GGBFS with various solid/liquid and alkaline activator ratios had been determined by performing a number of compressive strength tests. It was found that GGBFS with 3.0 solid/liquid ratio and 2.5 alkaline activator ratio resulted in high compressive strength at 168.7 MPa after 28 days of curing. The microstructure analysis of the GGBFS geopolymers using SEM, FTIR and XRD revealed the formation of tobermorite and calcite (CaCO3) phases within a three-dimensional system. In addition, an advanced characterisation non-destructive technique using the synchrotron micro-XRF was performed to reveal detail phase distribution in the system. It displayed that the calcium concentration was higher at silica and alumina regions, which described the formation of tobermorite and CaCO3 as the contributing factor towards high compressive strength.

Consumption of water containing high proportions of manganese could cause Parkinson's like symptoms and damage the central nervous systems. This study aims to investigate the potential of manganese removal through the development of microbial cell-immobilized biochar. The wood vinegar industry generates a large volume of carbonized wood waste (natural biochar) from the pyrolytic process. This is the first investigation utilizing this low value waste combined with biological treatment for water purification. Raw and hydrogen peroxide-modified biochars were used to immobilize an effective manganese-oxidizing bacterium, Streptomyces violarus strain SBP1 (SBP1). The results demonstrated that the modified biochar had a higher proportion of oxygen-containing functional groups leading to better manganese removal. Manganese adsorption by the modified biochar fitted pseudo-second-order and Langmuir models with the maximum adsorption capacity of 1.15 mg g−1. The modified biochar with SBP1 provided the highest removal efficiency at 78%. The advanced synchrotron analyses demonstrated that manganese removal by the biochar with SBP1 is due to the synergistic combination of manganese adsorption by biochars and biological oxidation by SBP1.

The GTAW method was employed for the dissimilar joining of OFHC copper and AISI 304 stainless steel. The special weld joint design of a modified socked-weld flange with edge joints made on short-flanged edges was used. The butt joint of the flange edges was designed to have different height and thickness. The welding was done without filler metal using a DC current of 80 A with pre-heating of the joint at 200 °C. The cross-sectional image of the specimen clearly indicated the fusion zone as a semicircular-shaped bead with the molten region about 0.7 mm from the top. The micro XRF mapping image revealed the heterogeneous elemental distributions of Cu, Fe, Cr, Ni and Mn in the fusion zone. The highest Mn concentration appeared in the Cu-rich area. At the interface, SEM images show the formation of small granules of Fe on the Cu side while the dendrites form near stainless steel. The structures of Fe and Cu were not changed during the welding process as determined by the XAS.

It is known that X-rays spectroscopy has been developed to apply to many advantages. In this work, Scanning electron microscope coupled with energy dispersive X-ray spectrometer (SEM-EDS) and synchrotron radiation facilities, such as micro-beam X-ray fluorescent spectroscopy (µ-XRF) and X-ray absorption spectroscopy (XAS) have been carried out to study on impregnated activated carbon samples that have been used as a chemical warfare agent adsorbent in military protective equipment. The elemental composition and distribution of sample surface have been analyzed. Their microstructures were highly porous. The results showed a detection of many kinds of metals, especially chromium (Cr), iron (Fe) and copper (Cu) with different from elemental distribution. It was also detected Cr(VI) which was a carcinogen in some samples. It is proposed that these methods can be used as fingerprint to identify various types of adsorbent.

We report a columnar superlattice formed by blends of dendron-like Li 3,4,5-tris(n-alkoxy)benzoates with n-alkanes. Without the alkane, the wedge-shaped molecules form liquid crystal columns with 3 dendrons in a supramolecular disk. The same structure exists in the blend, but on heating one dendron is expelled from the disks in every third column and is replaced by the alkane. This superlattice of unequal columns is confirmed by complementary X-ray and neutron diffraction studies. Lateral thermal expansion of dendrons normally leads to the expulsion of excess molecules from the column, reducing the column diameter. However, in the already narrow columns of pure Li salt, expulsion of one of only three dendrons in a disk is not viable. The added alkane facilitates the expulsion, as it replaces the missing dendron. Replacing the alkane with a functional compound can potentially lead to active nanoarrays with relatively large periodicity by using only small molecules.

Glycolipid, found commonly in membranes, is also a liquid crystal material which can self-assemble without the presence of a solvent. Here, the dielectric and conductivity properties of three synthetic glycolipid thin films in different thermotropic liquid crystal phases were investigated over a frequency and temperature range of (10(-2)-10(6) Hz) and (303-463 K), respectively. The observed relaxation processes distinguish between the different phases (smectic A, columnar/hexagonal, and bicontinuous cubic Q) and the glycolipid molecular structures. Large dielectric responses were observed in the columnar and bicontinuous cubic phases of the longer branched alkyl chain glycolipids. Glycolipids with the shortest branched alkyl chain experience the most restricted self-assembly dynamic process over the broad temperature range studied compared to the longer ones. A high frequency dielectric absorption (Process I) was observed in all samples. This is related to the dynamics of the hydrogen bond network from the sugar group. An additional low-frequency mechanism (Process II) with a large dielectric strength was observed due to the internal dynamics of the self-assembly organization. Phase sensitive domain heterogeneity in the bicontinuous cubic phase was related to the diffusion of charge carriers. The microscopic features of charge hopping were modelled using the random walk scheme, and two charge carrier hopping lengths were estimated for two glycolipid systems. For Process I, the hopping length is comparable to the hydrogen bond and is related to the dynamics of the hydrogen bond network. Additionally, that for Process II is comparable to the bilayer spacing, hence confirming that this low-frequency mechanism is associated with the internal dynamics within the phase.

We report commissioning results and performance of X-ray absorption spectroscopy (XAS) beamline, BL-8, at the Siam Photon Laboratory. BL-8 has been opened for users since the year 2006. It is tunable by a fixed-exit double crystal monochromator equipped with InSb(1 1 1), Si(1 1 1), and Ge(2 2 0) crystals covering photon energy from 1830 to 9000 eV. Thus elemental absorption K-edges of silicon up to copper can be investigated. Other heavier elements may be studied via their L or M edges. The front end is windowless and the beamline is terminated with a Kapton window followed by the XAS station equipped with ionization chambers for transmission-mode measurements. The measured photon flux at sample is approximately 10 8 –10 10 photons/s/100 mA for the 1 mm×10 mm beam size. The commissioning XANES spectra of sulfur standards and EXAFS spectra of copper are presented.

A bending magnet beamline has been constructed and commissioned for x‐ray absorption spectroscopy (XAS) at the Siam Photon Laboratory. The photon energy is tunable from 1830 eV to 8000 eV using a Lemmonier‐type, fixed‐exit double crystal monochromator equipped with InSb(111), Si(111), Ge(220) crystals. Elemental K‐edges are then accessible from silicon to iron. A series of low conductance vacuum tubes has been designed and installed between the pumping chambers in the front end to obtain the proper pressure difference between the upstream and the downstream of the front end. Thus lower‐energy photons, around K‐edges of silicon, phosphorous, and sulfur, can be delivered to the experimental XAS station without being absorbed by a window. In this report, the design of the beamline is described. The commissioning results including the measured photon flux at sample and experimental XAS spectra are presented.

A Small Angle X-ray Scattering (SAXS) beamline has been constructed at the Siam Photon Laboratory of the Synchrotron Light Research Institute (SLRI), Thailand. The beamline was commissioned and opened for users in March 2011. In order to maximize the photon flux, a Double Multilayer Monochromator was adopted to monochromatize synchrotron x-rays within the energy range of 6-9 keV. The experimental station is equipped with a CCD detector for SAXS measurements and an Image Plate for wide angle x-ray scattering (WAXS) measurements. Apparatus for in-situ measurements have been developed to enable studies of nano structural changes during temperature and tensile variation. Capability for scattering measurements in absolute unit has been investigated. This work reports the current status of the beamline and results from dispersed Au nanoparticles measurements.

This paper investigates the effects of different weight percentages (0, 0.5, 1.0, 1.5 and 2.0 wt.%) of kaolin geopolymer ceramic (KGC) on the microstructure formation, thermal properties, spreadability and joint strength in Sn-3.0Ag-0.5Cu (SAC305) lead-free solder alloys in order to develop a new composite solder system. Advanced characterization techniques such as Electron backscatter diffraction (EBSD) and synchrotron micro-XRF were used to study the behaviors of the pure SAC305 and KGC reinforced SAC305 composite solders. Experimental results shows that the addition of KGC refines the β-Sn area and increases the eutectic area with fine intermetallics formation. In addition, the thickness of the IMC layer is reduced with a reduction in undercooling value for the KGC reinforced SAC305 composite solder. The spreadability of the KGC reinforced SAC305 composite solder is significantly increased in the spreadable area with a higher strength of solder joint. Significantly, the results obtained prove that 1.0 wt.% KGC addition gives better performance in terms of microstructure formation, thermal properties, spreadability and joint strength. Synchrotron micro-XRF interestingly indicated that some Al and Si, which are the major elements in geopolymer systems, migrate into the solder area.