Preparation and characterization of copper/copper-coated silicon carbide composites for electronic packaging / Azida Azmi

Metal matrix composites (MMCs) have great potentials as packaging materials among other composite groups because the properties can be engineered to the design needs. Copper matrix reinforced with silicon carbide particles has greater potential due to the fact that it has higher thermal conductivity compared to the widely used aluminum. However, the bonding between the copper matrix and the SiC reinforcement must be improved since there is interface issues which affect the thermophysical properties of the CuSiC composites. Therefore, the SiC is coated with a thin copper film via electroless coating technique which is least expensive, simple and can provide homogenous copper deposits. The SiC is first need to be cleaned, etched, sensitized and activated to prepare the SiC particles surface for copper to be deposited onto it. Then, an electroless copper coating bath is prepared and the SiC is coated under suitable temperature and pH to obtain a good coating on SiC particles. Then, the CuSiC composites are fabricated via powder metallurgy methodology by ball milling to mix the copper matrix and SiC reinforcement. Then the mixture is pressed under uniaxial compaction loading and sintered at 925oC for 2 hours. Then the samples are ready for characterization and testing. The SEM images showed the difference between the raw SiC and cleaned SiC after ultrasonically cleaned in solvent. After sensitizing and activation process, the SEM image showed that it has the catalytic elements during the activation process. Then, the SEM image after coating process showed the copper deposits on the SiC particles surface. The particle size distribution has increased from 45.639mm before cleaning to 45.993mm after cleaning. Then the size increased to 46.750mm after sensitizing and activation process. Then, the size increased to 48.100mm after coating process

Factors Influencing Students’ Academic Aspirations in Higher Institution: A Conceptual Analysis

AbstractHigher education is critical success of young adults. Higher education can provide a gateway for social mobility and play a critical role in countering social stratification in Malaysia, particularly for the Bumiputera students in Malaysia society. However, change hurts. The transition from school to university is a change that every school students have to face in their quest for higher education. The current scenario giving some signals that there is a challenging life transition in the development of young adults, and many students are inadequately prepared for the psychological, emotional, and academic realities of higher education. These new university students are confronted with the adaptational challenges of living apart from family and friends, adjusting to the academic regimen, assuming responsibility for the tasks of daily living, and developing a new array of social relationships with peers and faculty. Futhermore, not many research have been conducted on this issue except that focused had been made to the secondary and/or high school students only. Therefore, this paper takes the challenge of filling these gaps by analysing some crucial conceptual undertanding what factors exactly influence the student's life at the higher institution

Influence of Filler Surface Modification on Static and Dynamic Mechanical Responses of Rice Husk Reinforced Linear Low-Density Polyethylene Composites

Filler surface modification has become an essential approach to improve the compatibility problem between natural fillers and polymer matrices. However, there is limited work that concerns on this particular effect under dynamic loading conditions. Therefore, in this study, both untreated and treated low linear density polyethylene/rice husk composites were tested under static (0.001 s-1, 0.01 s-1 and 0.1 s-1) and dynamic loading rates (650 s-1, 900 s-1 and 1100 s-1) using universal testing machine and split Hopkinson pressure bar equipment, respectively. Rice husk filler was modified using silane coupling agents at four different concentrations (1, 3, 5 and 7% weight percentage of silane) at room temperature. This surface modification was experimentally proven by Fourier transform infrared and Field emission scanning electron microscopy. Results show that strength properties, stiffness properties and yield behaviour of treated composites were higher than untreated composites. Among the treated composites, the 5% silane weight percentage composite shows the optimum mechanical properties. Besides, the rate of sensitivity of both untreated and treated composites also shows great dependency on strain rate sensitivity with increasing strain rate. On the other hand, the thermal activation volume shows contrary trend. For fracture surface analysis, the results show that the treated LLDPE/RH composites experienced less permanent deformation as compared to untreated LLDPE/RH composites. Besides, at dynamic loading, the fracture surface analysis of the treated composites showed good attachment between RH and LLDPE

Mechanical and Dielectric Properties of Hybrid Carbon Nanotubes-Woven Glass Fibre Reinforced Epoxy Laminated Composites via the Electrospray Deposition Method

Herein, the effects of multi-walled carbon nanotubes (CNTs) on the mechanical and dielectric performance of hybrid carbon nanotube-woven glass fiber (GF) reinforced epoxy laminated composited are investigated. CNTs are deposited on woven GF surface using an electrospray deposition method which is rarely reported in the past. The woven GF deposited with CNT and without deposited with CNT are used to produce epoxy laminated composites using a vacuum assisted resin transfer moulding. The tensile, flexural, dielectric constant and dielectric loss properties of the epoxy laminated composites were then characterized. The results confirm that the mechanical and dielectric properties of the woven glass fiber reinforced epoxy laminated composited increases with the addition of CNTs. Field emission scanning electron microscope is used to examine the post damage analysis for all tested specimens. Based on this finding, it can be prominently identified some new and significant information of interest to researchers and industrialists working on GF based products