Effectiveness of dimple microtextured copper substrate on performance of Sn-0.7Cu solder alloy

This paper elucidates the influence of dimple-microtextured copper substrate on the performance of Sn-0.7Cu solder alloy. A dimple with a diameter of 50 µm was produced by varying the dimple depth using different laser scanning repetitions, while the dimple spacing was fixed for each sample at 100 µm. The dimple-microtextured copper substrate was joined with Sn-0.7Cu solder alloy using the reflow soldering process. The solder joints’ wettability, microstructure, and growth of its intermetallic compound (IMC) layer were analysed to determine the influence of the dimple-microtextured copper substrate on the performance of the Sn-0.7Cu solder alloy. It was observed that increasing laser scan repetitions increased the dimples’ depth, resulting in higher surface roughness. In terms of soldering performance, it was seen that the solder joints’ average contact angle decreased with increasing dimple depth, while the average IMC thickness increased as the dimple depth increased. The copper element was more evenly distributed for the dimple-micro-textured copper substrate than its non-textured counterpart

Microstructure and mechanical properties of plasma sprayed Al

This paper focused on the effect of deposition conditions on the microstructural and mechanical properties of the ceramic coating. In this study, Al2O3 – 13%TiO2 coated mild steel were prepared by using atmospheric plasma spray technology with different plasma power ranging from 25 kW to 40 kW. The as-sprayed coatings consist of γ-Al2O3 phase as the major phase and small amount of the titania phase existed in the coating structure. High degree of fully melted region was observed in the surface morphology for the coating sprayed with high plasma power, which lead to the high hardness and low percentage of porosity. In this study, nanoindentation test was carried out to investigate mechanical properties of the coating and the results showed that the coatings possess high elastic behaviour, which beneficial in engineering practice

Microstructure and mechanical properties of plasma sprayed Al2O3 – 13%TiO2 Ceramic Coating

This paper focused on the effect of deposition conditions on the microstructural and mechanical properties of the ceramic coating. In this study, Al2O3 – 13%TiO2 coated mild steel were prepared by using atmospheric plasma spray technology with different plasma power ranging from 25 kW to 40 kW. The as-sprayed coatings consist of γ-Al2O3 phase as the major phase and small amount of the titania phase existed in the coating structure. High degree of fully melted region was observed in the surface morphology for the coating sprayed with high plasma power, which lead to the high hardness and low percentage of porosity. In this study, nanoindentation test was carried out to investigate mechanical properties of the coating and the results showed that the coatings possess high elastic behaviour, which beneficial in engineering practice

Effect of LST parameter on surface morphology of modified copper substrates

This study aimed to investigate the effect of laser surface texturing (LST) parameter on the surface morphology of copper substrate. The results of different loop number (L1 to L5) on the resolidified material of micro-dimpled surface modified copper substrate were examined. The micro-dimple with a diameter of 100 μm was produced via LST process by varying the dimple distance at 100 μm and 180 μm. The resolidified material that was formed after the surface texturing process was analysed using 3D measuring laser microscope. Based on the data collected, the dimple was successfully engraved on the copper substrate. The increasing number of loop increase the quantity of the melted material which lead to higher amount of resolidified material and surface roughness

Effect of surface finish on the wettability and electrical resistivity of Sn-3.0Ag-0.5Cu solder

The effect of different surface finish with Sn-3.0Ag-0.5Cu (SAC305) solder was successfully investigated. The SAC305 solder was fabricated by using casting method and solder was placed on copper substrate that coated with different surface finish. The soldering process was carried out by using F4N reflow oven followed up with the mounted and metallographic steps. Wettability of SAC305 solder was observed through contact angle formed between solder and four different surface finish located on the copper substrate. Subsequently, the electrical resistivity of solder was studied by conducted the four-point probes. The results of wettability test was found to be in the accepted range which is below 45° for all different surface finish. In terms of electrical resistivity, the results showed that the ImAg surface finish had enhanced the electrical conductivity of SAC305 lead-free solder

Characterization of SnO2/TiO2 with the Addition of Polyethylene Glycol via Sol-Gel Method for Self-Cleaning Application

TiO2 is one of the most widely used metal oxide semiconductors in the field of photocatalysis for the self-cleaning purpose to withdraw pollutants. Polyethylene glycol (PEG) is recommended as a stabilizer and booster during preparation of water-soluble TiO2. Preparation of SnO2/TiO2 thin film deposition on the surface of ceramic tile was carried out by the sol-gel spin coating method by adding different amount of PEG (0g, 0.2g, 0.4g, 0.6g, 0.8g) during the preparation of the sol precursor. The effects of PEG content and the annealing temperature on the phase composition, crystallite size and the hydrophilic properties of SnO2/TiO2 films were studied. The X-ray diffraction (XRD) spectra revealed different phases existed when the films were annealed at different annealing temperatures of 350°C, 550°C and 750°C with 0.4 g of PEG addition. The crystallite sizes of the films were measured using Scherrer equation. It shows crystallite size was dependent on crystal structure existed in the films. The films with mixed phases of brookite and rutile shows the smallest crystallite size. In order to measure the hydrophilicity properties of films, the water contact angles for each film with different content of PEG were measured. It can be observed that the water contact angle decreased with the increasing of the content of PEG. It shows the superhydrophilicity properties for the films with the 0.8 g of PEG annealed at 750°C. This demonstrates that the annealed temperature and the addition of PEG affect the phase composition and the hydrophilicity properties of the films

Metal-Doped TiO₂ Thin Film as an Electron Transfer Layer for Perovskite Solar Cells: A Review

The electron transfer layer (ETL) plays a vital role in achieving high-performance perovskite solar cells (PSCs). Titanium dioxide (TiO2) is primarily utilised as the ETL since it is low-cost, chemically stable, and has the simplest thin-film preparation methods. However, TiO2 is not an ideal ETL because it leads to low conductivity, conduction band mismatch, and unfavourable electron mobility. In addition, the exposure of TiO2 to ultraviolet light induces the formation of oxygen vacancies at the surface. To overcome these issues, doping TiO2 with various metal ions is favourable to improve the surface structure properties and electronic properties. This review focuses on the bulk modification of TiO2 via doping with various metal ions concentrations to improve electrical and optical properties, charge carrier density, and interfacial electron–hole recombination, thus contributing to enhancing the power conversion efficiency (PCE) of the PSCs

Effectiveness of Dimple Microtextured Copper Substrate on Performance of Sn-0.7Cu Solder Alloy

This paper elucidates the influence of dimple-microtextured copper substrate on the performance of Sn-0.7Cu solder alloy. A dimple with a diameter of 50 µm was produced by varying the dimple depth using different laser scanning repetitions, while the dimple spacing was fixed for each sample at 100 µm. The dimple-microtextured copper substrate was joined with Sn-0.7Cu solder alloy using the reflow soldering process. The solder joints’ wettability, microstructure, and growth of its intermetallic compound (IMC) layer were analysed to determine the influence of the dimple-microtextured copper substrate on the performance of the Sn-0.7Cu solder alloy. It was observed that increasing laser scan repetitions increased the dimples’ depth, resulting in higher surface roughness. In terms of soldering performance, it was seen that the solder joints’ average contact angle decreased with increasing dimple depth, while the average IMC thickness increased as the dimple depth increased. The copper element was more evenly distributed for the dimple-micro-textured copper substrate than its non-textured counterpart