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The purpose of this paper is to investigate and find out the surface and electrochemical behaviours of twin roll cast (TRC) 8006 aluminium alloy with different thicknesses due to the cold rolling rates after the TRC process.

The 8006 aluminium alloys are mostly used for the food packaging industry, as they are corrosion resistant, lightweight and shapable materials. The present work investigates the surface and corrosion behaviours of 8006 aluminium alloys at different thicknesses. TRC aluminium alloys were cold-rolled at two different reduction rates before investigation. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDX) tests were used to examine the phase and elemental analyses. FE-SEM and 3D profilometry also used to observe surface morphology. Open circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy tests (EIS) were carried out to find out corrosion behaviours. The results show that the more cold rolling reduction (CRR), the more corrosion rate and surface affection of the TRC 8006 aluminium alloys.

According to the electrochemical tests (OCP, potentiodynamic polarization test and EIS) and surface morphology results (such as SEM, 3D profilometry and XRD) the more the rolling rate the less the corrosion resistance.

First corrosion behaviour investigation of twin-rolled 8006 Al alloys using electrochemical techniques. First investigation of CRR effects on electrochemical corrosion behaviour of 8006 Al alloys with 3.5 wt.% NaCl solution using EIS. First investigation of 8006 Al alloys as a food packaging material with electrochemical ways.

The purpose of this paper is to conduct a comparative study of the surface modifications induced by two different lasers on a 2050‐T8 aluminum alloy, with a specific consideration of residual stress and work‐hardening levels.

Two lasers have been used for Laser shock peening (LSP) treatment in water‐confined regime: a Continuum Powerlite Plus laser, operating at 0.532 mm with 9 ns laser pulses, and near 1.5mm spot diameters; a new generation Gaia‐R Thales laser delivering 10 J‐10 ns impacts, with 4‐6mm homogeneous laser spots at 1.06 mm. Surface deformation, work‐hardening levels and residual stresses were analyzed for both LSP conditions. Residual stresses were compared with numerical simulations using a 3D finite element (FE) model, starting with the validation of surface deformations induced by a single laser impact.

Similar surface deformations and work‐hardening levels, but relatively lower residual stresses were obtained with the new large 4‐6 mm impact configuration. This was attributed to a reduced number of local cyclic loadings (2) compared with the small impact configuration (4). Additionally, more anisotropic stresses were obtained with small impacts. FE simulations using Johnson‐Cook's material' behavior were shown to simulate accurately surface deformations, but to overestimate maximum stress levels.

This work should provide LSP workers a better understanding of the possible benefits from the different LSP configurations currently co‐existing: using small (<2 mm) impacts at high‐cadency rates or large ones (>4‐5 mm). Moreover, experimental results and simulated data had never been presented on 2050‐T8 Al alloy.

An experimental (and numerical) comparison using two distinct laser sources for LSP, has never been presented before. This preliminary work should help LSP workers to choose adequate sources.

Introduction Much work has been done on the phenomenon of electropolishing since it was discovered by Jaquat. Most of this work was directed towards the elucidation of the polishing mechanism as well as establishing conditions for polishing of different metals and alloys. Studies on the polishing mechanism have revealed that electropolishing is a diffusion‐controlled process, which takes place at the limiting current, and electropolishing can therefore be treated quantitatively using the theory of mass transfer to the cathodic deposition of metal and metal powder. Some work has been done on the study of electropolishing under forced convection mass transfer conditions. A notable recent investigation involving copper and copper‐based alloys in a stirred cell is due to the study of Gabe and strongly suggests a diffusion‐limited mechanism at low temperature. Fouad et al. studied mass transfer under free convection in the electropolishing of vertical copper electrodes in phosphoric acid.

This paper aims to determine the optimum set of temperatures through correlation study to attain the most effective capillary flow of underfill in a multi-stack ball grid array (BGA) chip device.

Finite volume method is implemented in the simulation. A three-layer multi-stack BGA is modeled to simulate the underfill flow. The simulated models were well validated with the previous experimental work on underfill process.

The completion filling time shows high regression R-squared value of up to 0.9918, which indicates a substantial acceleration on the underfill process because of incorporation of thermal delta. An introduction of 11 °C thermal delta to the multi-stacks BGA managed to reduce the filling time by up to 16.4%.

Temperature-induced capillary flow is a relatively new type of driven underfill designed specifically for package on package BGA components. Its simple implementation can further improve the productivity of existing underfill process in the industry that is desirable in reducing the process lead time.

The effect of temperature-induced capillary flow in underfill encapsulation on multi-stacks BGA by means of statistical correlation study is a relatively new topic, which has never been reported in any other research according to the authors’ knowledge.

The purpose of this study is to analyze the export competitiveness of Pakistan with border-sharing countries, i.e. Afghanistan, China, India and Iran for the year 2014.

The study uses revealed symmetric comparative advantage (RSCA) index to measure export competitiveness with border-sharing countries. The study has split the results into highest and marginal comparative advantage and disadvantage according to the rank.

Pakistan is exporting 160, 155, 133 and 60 commodities at three-digit level of Standard International Trade Code (Rev 3) classification to Afghanistan, China, India and Iran, respectively. The results suggest that Pakistan has highest and marginal comparative disadvantage in more than half of these commodities exported to border-sharing countries. Pakistan can improve its market share for rice in Afghanistan, China and Iran. Special measures and productive efforts are required to improve the export competitiveness of cotton, textile yarn and cotton fabric in border-sharing countries.

Pakistan has to adopt special strategies to improve the competitiveness of those commodities that fall in marginal comparative advantage and disadvantage. To increase the volume of cross-border trading, political and diplomatic channels are required among the countries especially the border-sharing countries.

Export competitiveness of Pakistan is analyzed for all the commodities exported to border-sharing countries and categorized into highest and marginal comparative advantage and disadvantage. To avoid the problem of asymmetry in Balassa index revealed comparative advantage, RSCA index is used.