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The continuous miniaturization of electronic products and the constantly rising functionality demand by final users necessitate major challenges for the academia and the industry to produce reliable lead-free solders for long-term service. In the present study, an analysis on the influence of MWCNTs (multi-walled carbon nanotubes) on the interfacial IMC (intermetallic compound) evolution and shear strength of Sn–5Sb solder joint was performed. The composite solder joint samples were developed through the reflow soldering process and thereafter subjected to isothermal aging at different temperatures (120 °C, 150 °C and 170 °C). Given the promising properties of MWCNTs, empirical findings showed that inhibited interfacial IMC evolution and enhanced shear strength were markedly achieved due to the presence of MWNCTs in the Sn–5Sb solder alloy. Artificial neural network (ANN) model was developed by making use of the experimental data to characterize the composite solder joints. Various influential parameters that affect the thickness of the IMC layer and the shear strength performance of the composite solder joints including the MWCNTs content, aging temperature and aging time were considered as the input parameters for the ANN model. Having used the statistical parameters such as the coefficient of determination (R2) and root mean square error (RMSE) to evaluate the model, the ANN model developed in this study adequately predicted the IMC layer thickness (R2 = 0.9913; RMSE = 0.0234) and shear strength (R2 = 0.9798; RMSE = 0.0314) of the composite solder joints.

In this study, the synergetic effect of multi-walled carbon nanotubes (MWCNTs) and porous Cu interlayer (PCI) on the intermetallic compound (IMC) formation and shear strength of Sn–3.0Ag–0.5Cu (SAC 305) solder system was investigated. The solder joints were prepared by subjecting two different series of MWCNTs-reinforced SAC 305 solder systems (i.e., SAC–0.01CNT and SAC–0.04CNT) sandwiched with porous Cu interlayer having pores per inch (PPI) of 15, 25 and 50 to reflow soldering on Cu substrate. Electron microscopy and spectroscopy techniques were used to view and detect the intermetallic compound phases, respectively. The scallop-shaped Cu6Sn5 IMC phase was observed at the solder/PCI interface, while on the other hand, an additional layer-type Cu3Sn IMC phase formed alongside the Cu6Sn5 IMC at the solder/Cu interface. Given the promising properties of PCI material, empirical findings showed that the presence of PCI in the solder joint inhibited the formation of interfacial IMC layer at the solder/Cu substrate with the SAC–0.01CNT–25PCI exhibiting the least IMC thickness. More so, the PCI material effectively enhanced the shear strength of the MWCNTs-reinforced composite solder joints. Generally, the strengthening capacity of the PCI material was greatly underscored in the SAC–0.01CNT–xPCI series with the sample prepared with PCI of 15 PPI demonstrating the superior shear strength of 21.1 MPa.

In this study, the joint effect of rice husk ash (RHA) reinforcement as an alternative silica source and electroless nickel immersion silver (ENIAg) surface finish on the intermetallic compound (IMC) formation and shear strength of the Sn–0.7Cu solder system was investigated. A series of plain and composite lead-free solder systems (Sn–0.7Cu−xRHA; x = 0, 0.01, 0.05 and 0.1 wt%) was successfully developed and subjected to reflow soldering on bare Cu and ENIAg surface finish. After conducting a comprehensive microstructural study using the scanning electron microscopy and energy dispersive spectroscopy techniques, the Cu6Sn5 and Cu3Sn intermetallic compound (IMC) phases were observed at the interface of the Sn–0.7Cu−xRHA/Cu composite solder joints. On the other hand, the (Cu,Ni)6Sn5 and Ni3Sn4 IMC phases dominated the interface of the Sn–0.7Cu−xRHA/ENIAg counterparts. Given the promising potential of the ENIAg surface finish, the Sn–0.7Cu−xRHA/ENIAg exhibited IMC thickness values within a range of 3.81–4.74 µm as compared to the 6.13–9.3 µm range exhibited by the Sn–0.7Cu−xRHA/Cu counterpart. More so, the ENIAg surface finish was effective in improving the shear strength of the plain solder joint, with the Sn–0.7Cu/ENIAg exhibiting 13.44 MPa relative to the 11.5 MPa exhibited by the Sn–0.7Cu/Cu counterpart. Overall, the strengthening effect of the RHA reinforcement was well marked in the Sn–0.7Cu−xRHA/Cu composite solder joints with the composite having 0.1 wt% RHA exhibiting the highest shear strength (14.6 MPa) across the board.

The harmful effect of agricultural waste has been intensified over the last decade and impacts the environment every passing day. Rice husk waste is a major problem in Turkey and the far east countries. Due to the economic dependence of the mass cultivation and the production of rice, the disposal of the waste appears both time and money consuming. Alternative methods sought over the years and the implementation of the rice husk in the production of composites is seen as a promising method. RHA is a burning residue of rice husk and the implementation of RHA in the production of aluminum composites gained attention in recent years. In this study, aluminum composites having 5 wt.% Al2O3 reinforcement and 5 wt.% Al2O3/0.5, 1.0, and 1.5 wt.% RHA reinforcement were produced by vacuum infiltration process which is a cheap and cost-effective route. AA7075 alloy without any reinforcement was produced for comparison. Solution heat treatment at 480 °C for 2 hours was applied and then quenched following by aging heat treatment at 120 °C for 8 hours. The microstructure, microhardness, and wear tests of all composites were investigated. Increasing RHA content up to 1 wt.% and aging heat treatment increased the hardness of composites. Abrasion coefficient decreased by increasing RHA content.

Dele-Afolabi, Temitope Theophilus/0000-0003-0187-9208; Mohamed Yusoff, Mohd Zuhri/0000-0002-1069-7345 WOS:000567564500001 In this work, the effects of porosity and different particle sizes of pore-forming agent on the mechanical properties of porous alumina ceramics have been reported. Different grades of porous alumina ceramics were developed using corn cob (CC) of different weight contents (5, 10, 15, and 20 wt%) and particle sizes (

Currently, the development and manufacturing of enhanced performance product with high-performance bio-based materials has been one of the aspiring purposes by engineers and researchers throughout the globe. For the past several decades, the conventional-based product was shown an increasing trend due to the significant growth of the global demand towards the material, which was attributed to its diverse and universal properties to be used in the development of science and technology. The materials are widely used, especially, for structural purposes in the automotive, marine, aerospace, food packaging, and construction sectors due to their lightweight properties such as higher strength and durability. Around 140 million tons of petroleum-based polymers is manufactured globally. However, petroleum-based polymers show negative effects on the environment, which leads to several issues, including health problems and pollution. Moreover, the majority of conventional plastics that are used end up in landfill areas. These observations showed that the synthetic plastics contribute to the major solid waste environmental pollutants. Subsequently, the increased cost and the negative effect on environment make the engineers and researchers show high interest in polymer biodegradation.

Natural fiber reinforced composites have had a great impact on the development of eco-friendly industrial products for several engineering applications. Sugar palm fiber (SPF) is one of the newly found natural fibers with limited experimental investigation. In the present work, sugar palm fiber was employed as the natural fiber reinforcement. The composites were hot compressed with polyvinyl butyral (PVB) to form the structure of laminated composites and then were subjected to tensile testing and moisture absorption. The maximum modulus and tensile strength of 0.84 MPa and 1.59 MPa were registered for samples PVB 80-S and PVB 70-S, respectively. Subsequently, the latter exhibited the highest tensile strain at a maximum load of 356.91%. The moisture absorption test revealed that the samples exhibited better water resistance as the proportion of PVB increased relative to the proportion of SPF due to the remarkable hydrophobic property of PVB in comparison with that of SPF.

Temitope, Dele-Afolabi/0000-0003-0187-9208; Sobri, Shafreeza/0000-0002-5675-2186 WOS: 000440527300010 In the present study, an analysis on the combined effect of nickel (Ni) reinforcement and pore former type in characterizing the corrosion behavior of composite porous alumina ceramics was performed. In order to showcase the potential of the new porous ceramics, pore-forming agents (PFAs) from rice husk (RH) and sugarcane bagasse (SCB) were used in shaping the plain and composite porous alumina samples having sample formulation of Al2O3-xNi-PFA; x = 0, 2, 4, 6 and 8 wt%. Results showed that the emergence of a highly stable Ni3Al2SiO8 spinelloid phase in the RH-graded composites enhanced their chemical stability in the corrosive mediums (10 wt% NaOH and 20 wt% H2SO4) relative to the plain and the corresponding SCB-graded counterparts. An artificial neural network (ANN) model has been developed for predicting the corrosion behavior of the plain and composite porous alumina ceramics based on the experimental data. The developed ANN model satisfactorily predicted the percent mass losses of the porous ceramics in strong alkali and strong acid solutions with coefficient of determination (R-2) of approximately 0.99. Research Management Center of Universiti Putra Malaysia [GP-IPS/2016/9486500]; Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey [2016/44] The authors are thankful to the Research Management Center of Universiti Putra Malaysia for providing financial support (GP-IPS/2016/9486500) to carry out this research study. The authors also acknowledge the Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey for the ongoing partnership, financial support (project number of 2016/44) and fruitful feedback.

Sobri, Shafreeza/0000-0002-5675-2186; Temitope, Dele-Afolabi/0000-0003-0187-9208 WOS: 000432768200015 The mechanical performance and chemical stability of porous alumina materials operating under harsh service conditions are of utmost importance in understanding their operational behavior if they are to stand the test of time. In the present study, the joint effect of nickel (Ni) reinforcement and rice husk (RH) pore-forming agent (PFA) on the tensile strength and the corrosion resistance properties of composite porous alumina ceramics was studied. To exploit the potential of this new porous alumina system, plain and Ni-reinforced porous alumina samples (Al2O3-xNi-RH; x = 2, 4, 6 and 8 wt%) were developed through the powder metallurgy technique. Comprehensive investigation on the tensile strength properties of the developed porous alumina ceramics showed that relative to the plain sample (tensile strength and elastic modulus; 6.1 MPa and 1201 MPa), the presence of highly stable Ni3Al2SiO8 spinelloid promoted the tensile strength enhancement (12.6-6.4 MPa) and the elastic modulus decline (897-627 MPa) of the composite samples. Similarly, corrosion resistance test was performed on the composite porous alumina samples in both 10wt% NaOH and 20wt% H2SO4 hot aqueous solutions. Overall, the composite samples demonstrated superior chemical stability in NaOH solution as compared with the plain sample. On the other hand, the composites were more prone to attack in H2SO4 solution, except for the Al2O3-2Ni-10RH composite sample which maintained its superiority over the plain counterpart. Research Management Center of Universiti Putra Malaysia [GP-IPS/2016/9486500] The authors are thankful to the Research Management Center of Universiti Putra Malaysia for providing financial support (GP-IPS/2016/9486500) to carry out this research study. The authors also acknowledge the Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey for the ongoing partnership, endless support and fruitful feedback.

Temitope, Dele-Afolabi/0000-0003-0187-9208; Sobri, Shafreeza/0000-0002-5675-2186; Mazlan, Norkhairunnisa/0000-0003-0144-8360 WOS: 000427511200038 Porous alumina systems are suitable for application in wide-ranging industrial processes that require extreme service conditions such as high temperatures and corrosive mediums due to their remarkable thermal and chemical stability. Given the inherent brittleness of ceramics and their high sensitivity to thermo-mechanical loading, large-scale production of porous alumina components is constrained. In this study, the reinforcement of porous alumina ceramics with nickel (Ni) particles has been reported. Plain and Ni-reinforced porous alumina ceramics were developed through the powder metallurgy method with agro-waste materials from rice husk (RH) and sugarcane bagasse (SCB) as the pore-forming agents (PFAs). Experimental results showed that the formation of a stable Ni3Al2SiO8 spinelloid phase in the RH-graded composites actuated the emergence of a relatively refined microstructure while on the other hand, microstructural defects such as dislocated grains and localized voids were observed for the SCB-graded counterparts due to the presence of poorly crystallized NiAl2O4 spinel phase. Generally from the mechanical strength characterization, an inverse relationship was established between the mechanical properties and Ni reinforcement which agrees well with the Griffith's model. Moreover, the strengthening effect of the Ni3Al2SiO8 spinelloid phase was well marked in the RH-graded composites as maximum hardness, tensile and compressive strengths of 167.3HV, 12.6 MPa and 55.3 MPa respectively were achieved for the composite reinforced with 2 wt% Ni. (c) 2018 Elsevier B.V. All rights reserved. Research Management Center of Universiti Putra Malaysia [GP-IPS/2016/9486500]; Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey [2016/44] The authors are thankful to the Research Management Center of Universiti Putra Malaysia for providing financial support (GP-IPS/2016/9486500) to carry out this research study. The authors also acknowledge the Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey for the ongoing partnership, financial support (project number of 2016/44) and fruitful feedback.

Sobri, Shafreeza/0000-0002-5675-2186; Temitope, Dele-Afolabi/0000-0003-0187-9208 WOS: 000434275500025 This study demonstrates a simple and economically viable approach to fabricate porous alumina ceramics shaped with low-priced natural organic pore-forming agents (PFAs) from rice husk (RH) and sugarcane bagasse (SCB) of various weight contents using the powder metallurgy method. Experimental findings revealed that the total porosity (44-67vol%) and average pore size (70-178m) maintained a linear relationship with rising PFA inclusion. Using the diametral compression test, the mechanical response of porous alumina samples was evaluated as a function of porosity and pore geometry. From the overall mechanical strength characterization, the susceptivity of strength on porosity became well marked as the agro-waste shaped porous ceramics exhibited hardness, tensile strength, and elastic modulus of 529.1-26HV, 20.4-1.5MPa and 1662-57MPa, respectively. Moreover, the fractography of the RH and SCB graded porous alumina samples was evaluated as a function of the respective microstructural features. With a plausible tradeoff between pore interconnectivity and mechanical strength, recommended areas of application include solid oxide fuel cells (SOFCs) design, filtration, and thermal insulation systems. Research Management Center of Universiti Putra Malaysia [GP-IPS/2016/9486500]; Kirikkale University, Turkey [2016/44] Research Management Center of Universiti Putra Malaysia, Grant/Award Number: GP-IPS/2016/9486500; Kirikkale University, Turkey, Grant/Award Number: 2016/44

Macroporous ceramics with tailored porosity offer a great deal of advantage in wide-ranging industrial applications including fluid filtration, thermal insulation and lately, waste water treatment. To a large extent, attempts by researchers in enhancing the development of ample homogenous porous ceramics through the exploitation of state of the art processing technologies have thus far been successful. However, these technologies are capital intensive hence making room for more exploration in finding affordable alternatives. With the growing recognition of low cost sacrificial fugitives processing route for developing porous ceramic materials, pore forming agents from natural organic matters have been one of the most sought after materials for imbuing pores within ceramic matrices. This review intends to document the progress made thus far in the development of porous ceramic systems with natural organic matter inclusion. The article covers critical evaluation and comprehensive comparison of the fabrication routes and the physical properties of porous ceramics processed with varying natural organic matters.

1st International Postgraduate Conference on Mechanical Engineering (IPCME) -- OCT 31, 2018 -- Univ Malaysia Pahang, Pahang, MALAYSIA Temitope, Dele-Afolabi/0000-0003-0187-9208; Sobri, Shafreeza/0000-0002-5675-2186 WOS: 000461178900019 In this study, the effect of nickel (Ni) addition on the microstructure and corrosion resistance properties of porous alumina (Al2O3) composites shaped with sugarcane bagasse pore-forming agent were evaluated. Plain and Ni-reinforced porous alumina sampels (Al2O3-xNi-RH; x = 2, 4, 6 and 8wt%) were prepared using the powder metallurgy method. Experimental results showed that the porosity (50.4-57.1vol%) and the pore size (62-109 mu m) of the porous alumina composites increased with rising content of Ni reinforcement. The XRD results showed that the Al2O3 matrix and Ni reinforcement reacted during the heat treatment process to produce nickel aluminate (NiAl2O4) spinel. Corrosion resistance results showed that the porous alumina composites exhibited better chemical stability in strong alkali solution as compared with strong acid solution. Univ Malaysia Pahang, Fac Mech Engn, Pekan Campus

Dele-Afolabi, Temitope Theophilus/0000-0003-0187-9208 WOS: 000483694900038 In this study, the effect of multi-walled carbon nanotubes (MWCNTs) reinforcement on the intermetallic compound (IMC) layer growth and shear strength of Sn-5Sb-xCNT/Cu composite solder joints subjected to different isothermal aging conditions has been investigated. A series of plain and composite lead-free solder systems (Sn-5Sb-xCNT; x = 0, 0.01, 0.05 and 0.1 wt%) was successfully developed through the powder metallurgy method. Isothermal aging process was performed on the solder/Cu joints at 120 degrees C, 150 degrees C and 170 degrees C temperatures in order to investigate the evolution of the interfacial IMC layers and the shear strength property. Experimental results showed that the thickness of the total IMC layer increased with rising aging temperature. While the Cu3Sn IMC maintained a layer-type morphology for all aging conditions, morphology of the Cu6Sn5 IMC transformed from a scallop-type to a layer-type after aging at intermediate (150 degrees C) and high (170 degrees C) temperatures. Given the potential of MWCNTs as a reinforcement material, significant suppression in IMC layer growth was demonstrated by the composite solder joints relative to the plain counterpart. Comprehensive investigation on the growth kinetics showed that the presence of MWCNTs in the composite solder joints was effective in slowing down the diffusion mechanism responsible for IMC growth. Overall, the Sn-5Sb-0.05CNT composite solder joint exhibited the lowest diffusion coefficient within the range of 0.09 x 10(-14)-1.03 x 10(-14) cm(2)/s and 0.95 x 10(-14)-9.8 x 10(-14) cm(2)/s for Cu6Sn5 and Cu3Sn IMC layers respectively. Moreover, the strengthening effect of the MWCNTs reinforcement was well marked in the composite solder joints as the maximum shear strength within a range of 24.2-15.2 MPa was exhibited by the Sn-0.01CNT/Cu composite solder joint subjected to reflow soldering and isothermal aging conditions. (C) 2019 Elsevier B.V. All rights reserved. Research Management Center of Universiti Putra Malaysia [UPM/700-2/1/GPBI/2017/9553600]; Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey [BAP 2017/81, 2016/44] The authors are thankful to the Research Management Center of Universiti Putra Malaysia for providing financial support (UPM-Grant Putra; UPM/700-2/1/GPBI/2017/9553600) to carry out this research study. The authors also acknowledge the Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey for the ongoing partnership, financial support (project number of BAP 2017/81 and 2016/44) and fruitful feedback.

WOS:000539449500021 In this work, multi-walled carbon nanotubes (MWCNTs) reinforced Sn-5Sb/Cu composite solder joints were synthesized and the effects of MWCNTs addition on the microstructure evolution and hardness of the Sn-5Sb solder alloy during various thermal aging conditions were investigated. After conducing a thorough microstructural analysis, the SbSn and Cu6Sn5 intermetallic compounds (IMCs) were observed in the beta-Sn matrix of the composite solder joints subjected to reflow soldering while the latter was also present at the solder/Cu interface. However, after subjecting the composite solder joints to isothermal aging, the Cu3Sn IMC emerged between the Cu6Sn5 IMC at the solder/Cu interface and the Cu substrate. With the promising properties exhibited by MWCNTs as a reinforcement material, experimental results showed that MWCNTs refined the bulk solder microstructure and inhibited growth of the interfacial IMC layer in the Sn-5Sb-xCNT/Cu samples. In general, the composite sample reinforced with 0.05 wt% MWCNTs showed the least IMC layer thickness and diffusion coefficient in the ranges of 2.6-11.99 mu m and 1.07 x 10(-14 )-14.9 x 10(-14) cm(2)/s respectively. Meanwhile, the strengthening mechanism triggered by MWCNTs addition was clearly evident in the MWCNT-reinforced Sn-5Sb/Cu as superior hardness values within a range of 20.6-15.3 HV were registered for the as-soldered and aged composite solder joints with 0.05 wt% MWCNTs reinforcement. Research Management Center, Universiti Putra Malaysia (UPM-Grant Putra) [UPM/700-2/1/GPBI/2017/9553600]; Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey [BAP 2017/81, 2016/44] Y This study was supported by the Research Management Center, Universiti Putra Malaysia (UPM-Grant Putra; UPM/700-2/1/GPBI/2017/9553600) and the Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey (project number of BAP 2017/81 and 2016/44).

An analysis of the role played by the addition of carbon nanotubes (CNTs) to the solder matrix of conventional Sn-5Sb lead-free solder was performed. In a bid to determine the potential of this new solder system, the powder metallurgy approach was used to synthesise a plain Sn-5Sb solder system and CNTs reinforced composite solder formulations of Sn-5Sb-xCNT; x = 0.01wt.%, 0.05wt.% and 0.1wt.%. Isothermal aging study was conducted on the solder joints, to examine the evolution of the interfacial intermetallic compound (IMC) layer between solder and the adjoining copper (Cu) substrate. Similarly, shear strength analysis was performed on as-reflow and aged solder joints. A considerable improvement in the wetting properties, the microstructural evolution, and the interfacial intermetallic compound (IMC) layer growth was observed in the composite solder joints. Owing to the excellent mechanical properties of CNTs, the shear strength assessment revealed that the composite solder joints gave a superior shear strength property, especially the Sn-5Sb-0.01CNT solder joint sample.

In this study, the effects of multi-walled carbon nanotubes reinforcement on the thickness and growth kinetics of interfacial intermetallic compound (IMC) layer in Sn–5Sb solder system are investigated. In the typical study, plain Sn–5Sb solder system and carbon nanotubes reinforced solder systems (Sn–5Sb−xCNT; x = 0.01, 0.05 and 0.1 wt%) were developed via the powder metallurgy approach. The solder/Cu joints subjected to the as-reflow and isothermal aging (170 °C) conditions were systematically characterised to evaluate the growth of the IMC layer. Results suggest that the composite solders showed better results for all subjected conditions compared with the plain solder. In particular, 0.05 wt % CNTs reinforced solder system exhibited the most appreciable IMC layer suppression and diffusion coefficient among all the samples analysed in this study.

Temitope, Dele-Afolabi/0000-0003-0187-9208; Sobri, Shafreeza/0000-0002-5675-2186; Mazlan, Norkhairunnisa/0000-0003-0144-8360 WOS: 000402584900028 The strength integrity and chemical stability of porous alumina ceramics operating under extreme service conditions are of major importance in understanding their service behavior if they are to stand the test of time. In the present study, the effect of porosity and different pore former type on the mechanical strength and corrosion resistance properties of porous alumina ceramics have been studied. Given the potential of agricultural wastes as pore-forming agents (PFAs), a series of porous alumina ceramics (Al2O3-xPFA; x=5, 10, 15 and 20 wt%) were successfully prepared from rice husk (RH) and sugarcane bagasse (SCB) through the powder metallurgy technique. Experimental results showed that the porosity (44-67%) and the pore size (70-178 mu m) of porous alumina samples maintained a linear relationship with the PFA loading. Comprehensive mechanical strength characterization of the porous alumina samples was conducted not just as a function of porosity but also as a function of the different PFA type used. Overall, the mechanical properties showed an inverse relationship with the porosity as the developed porous alumina samples exhibited tensile and compressive strengths of 20.4-1.5 MPa and 179.5-10.9 MPa respectively. Moreover, higher strengths were observed in the SCB shaped samples up to the 15 wt% PFA mark, while beyond this point, the silica peak observed in the XRD pattern of the RH shaped samples favored their relatively high strength. The corrosion resistance characterization of the porous alumina samples in hot 10 wt% NaOH and 20 wt% H2SO4 solutions was also investigated by considering sample formulations with 5-15 wt% PFA addition. With increasing porosity, the mass loss range in RH and SCB shaped samples after corrosion in NaOH solution for 8 h were 1.25-3.6% and 0.44-2.9% respectively; on the other hand, after corrosion in H2SO4 solution for 8 h, the mass loss range in RH and SCB shaped samples were 0.62-1.5% and 0.68-3.3% respectively. Research Management Center of Universiti Putra Malaysia [GP-IPS/2016/9486500] The authors are thankful to the Research Management Center of Universiti Putra Malaysia for providing financial support (GP-IPS/2016/9486500) to carry out this research study. The authors also acknowledge the Department of Metallurgy and Materials Engineering, Kirikkale University, Turkey for the ongoing partnership, endless support and fruitful feedback.