Exploration dive finding the frogfish

A couple months back, my team and I went to Perhentian Island in Terengganu for a project called exploration dive. We were assisted by Mr Azharil Art from D’Lagoon Dive Centre, which was recommended by Mr Saiful Bahri Yakup, our team member who is a very well experienced diving instructor. We spent quite some time there with a few numbers of dive trip pursuing research related to marine life and the underwater environment. Nonetheless, this writing will only enumerate our work focusing on frogfish, including its behaviour, habitat, and species

14 UMPSA students participate in Introduction to Underwater Welding Programme

BANGI, 21 August 2023 – A total of 14 Universiti Malaysia Pahang Al-Sultan Abdullah (UMPSA) students recently participated in the Introduction to Underwater Welding Programme in Bangi, Selangor

Effects of Sintering Temperatures on Microstructures and Mechanical Properties of Sn4.0Ag0.5Cu1.0Ni Solder Alloy

This research was carried out to investigate the effects of sintering temperature on the properties of Sn-4.0Ag-0.5Cu-1.0Ni solder alloy by varying the temperatures. The Sn-4.0Ag-0.5Cu-1.0Ni solder alloy was prepared by using powder metallurgy method by press and sinter routes. 99.9% of pure Sn, Ag, Cu and Ni powder were used in this research where the pre-mixed powder undergoing milling process for 6 hours using a planetary ball machine. Hydraulic press machine was used to compact the solder powder at identically 5 tons(125 bars) for all samples. Five different temperatures of sintering specifically at 120℃, 150℃, 180℃, 220℃ and 250℃ were used. Characterizations on the microstructures such as grain size, thickness of intermetallic compound and, wettability angle were carried out using Scanning Electron Microscopy. Meanwhile, properties of the solder alloy were also evaluated through hardness and tensile test. It is expected that sintering process could be able to improve the strength of the solder joint by decreasing the intermetallic compound grain size. So far, most papers commonly used 180℃ as their sintering parameter without anyone providing the promising findings and various effects of the temperature onto solder. Therefore, this work is conducted to make a clarification and be the pilot study for the next sintering works for soldering. This paper reports experimental results of properties of Sn-4.0Ag-0.5Cu-1.0Ni solder alloy at different sintering temperatures

The Effectiveness of Bismuth Addition to Retard the Intermetallic Compound Formation

The aim of this paper is to study the effectiveness of bismuth addition in the solder alloy to retard the intermetallic compound formation and growth. In this study, three categories of solders such as Sn-4Ag-xCu (x = 0.5, 0.7, 1.0) and Sn-4Ag-0.5Cu-xBi (x = 0.1, 0.2, 0.4) were used. Ni/Au surface finish substrates were dipped into the molten solder at a temperature of 180-190 oC and allowed to cool at room temperature. The intermetallic compound (IMCs) were subjected to the characterization in terms of composition and morphology. The IMC phases were identified by energy dispersive x-ray (EDX), whereas the optical microscope and scanning electron microscopy (SEM) were used to observe microstructure evolution of the solder joint. The results clearly showed that copper concentration dependency was high during the reflow stage. Besides, only Ni3Sn4 and Ni3Sn2 were detected for all copper concentrations. The addition of Bi was found to have no significant effect on the type of IMCs formed, but yet the grain became further refined

Effect of microwave hybrid heating on mechanical properties and microstructure of Sn3.0Ag0.5Cu/Cu solder joints

Microwave hybrid heating (MHH) has become soldering’s alternative method for lead-free solder alloys due to its benefits towards modern microtechnology, such as shorter processing time, lower energy consumption and lower defect rate. Nonetheless, it still requires susceptors to improve its heating performance, such as SiC, which is known for its high loss factor under low microwave frequencies. In this study, the effect of microwave hybrid heating on mechanical properties, as well as the microstructure of solder joint between Sn3.0Ag0.5Cu (SAC305) solder alloy and Cu substrate was investigated. Solder joint was created using MHH with different soldering parameters (amount of SiC in a range of 3-7g and exposure time in a range of 7-10min) between SAC305 solder alloy (in the form of wire and paste) and Cu substrate. Then, a lap shear test was carried out following a standard of ASTM D1002 to determine solder joint strength. Characterization was made using an optical microscope and scanning electron microscopy. Results showed that solder wire produced the highest solder joint strength with the value of 115.45 MPa when using 3.05g of SiC for 8.92min soldering time. Meanwhile, the solder paste produced 109.76MPa solder joint strength when using 3.03 g of SiC for 9.39 min soldering time. The intermetallic compound (IMC) form was scallop-like Cu6Sn5, both solder/substrate joints with a thickness of 2.87 μm for solder wire and 3.62 μm for solder paste. Nonetheless, an excessive amount of SiC would generate more heat in MHH and increase the IMC thickness as well as reduce shear strength, which eventually decreases the solder joint stability