Advanced Materials Research Vol. 980

Abstract: In this work, deep drawing experiments have been performed in order to study formability of Ti-6Al-4V alloy sheet at temperature ranging from room temperature to 400⁰C. It is found that below 150⁰C, formability of the material is very poor and above 150⁰C till 400⁰C, limiting draw ratio (LDR) is found to be 1.8 which is substantially lesser than other structural alloys such as austenitic stainless steels. In order to understand qualitative aspects of formability, thickness distribution of drawn cup has been evaluated experimentally over a temperature range of 150⁰C - 400⁰C. Additionally, Finite Element (FE) analysis is done using a commercially available code Dynaform version 5.6.1 with LS-Dyna version 971 solver. 3-Parameter Barlat yield model is used for FE analysis. Predicted thickness distribution using FE simulation is in good agreement with experimental results.

Abstract: The industrial production of cement-based and lime-based materials such as mortars contributes significantly to the release of greenhouse gases such as CO₂ into the atmosphere. However, a percentage of these emissions is reabsorbed as the mortar hardens, owing to carbonation reactions. This study aims to explore the CO₂ sequestration capacity of a cement-based (CM) and a lime-based mortar (LM) over the first 28 days of curing. The CO₂ uptake of CM and LM was experimentally evaluated in mildly accelerated conditions by using a volumetric approach. This procedure enabled us to assess the CO₂ absorbed after 1, 7 and 28 days from mortar preparation so as to simulate CM and LM behavior during their setting, hardening, and service-life conditions. Through the experimental approach values of 19.1, 25.5 and 26.4 g CO₂/kg for CM and 5.0, 11.0 and 16.1 g CO₂/kg for LM were obtained. These results, which were validated by means of X-ray diffraction along with calcimetry analysis, confirmed that carbon sequestration by common mortars during their curing time is not negligible.

Abstract: Aluminum based Titanium carbide particulate reinforced metal matrix composite (Al-TiC PMMC) draws attention by many researchers & industries over alloy materials because of its excellent thermo-physical and mechanical characteristics. Despite of its superior properties of Al-TiC MMC, its complexity in manufacturing process and poor machinability has been the main deterrents to its application level. Controlling agglomeration of TiC particles is a challenging task to retain improved microstructure. The hard abrasive nature of carbide particles cause poor machinability and high machining cost. Therefore, in this paper an attempt has been made to study the various manufacturing techniques to achieve uniform distribution of TiC reinforcements in Al matrix.Further, the review follows the secondary manufacturing process of Al-TiC PMMC, which addressee’sthree topics: machining, forming & welding.

Abstract: The fabrication of micro or nano-structures on quartz substrate has attracted researchers' attention and interests in recent years due to a wide range of potential applications such as NEMS/MEMS, sensors and biomedical engineering. Various types of next generation lithographic methods have been explored since optical lithography physical limitations has hindered the fabrication of high aspects ratio (HAR) structure on quartz substrates. In this research, the top-down fabrication approach was employed to fabricate microstructures on quartz substrate using Electron Beam Lithography (EBL) system, followed by the pattern transfer process using Inductively Coupled Plasma-Reactive Ion Etching (ICP-RIE) technique. The factors that influenced pattern definition include the type of electron beam (e-beam) photoresist, e-beam exposure parameter such as spot size, working distance, write field, step size, e-beam current, dosage as well as the type of developer and its developing time. The optimum conditions were investigated in achieving micro or nano-structures. Field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray (EDX) and atomic force microscope (AFM) were utilized to characterize the structures profiles.

Abstract: Kelantan state, regarded as the cradle of Malay culture is not only known for her unique cultural heritage, but also a land blessed with both metallic and non-metallic minerals. These include enormous clay deposits discovered in six (6) districts with estimated total reserve of 29.4 million tonnes of ball clay and 51.5 million tonnes of mottled clay. Hence, this paper investigates the physiochemical and mineralogical properties of the clay deposits. This was achieved by reviewing existing literatures and reports at the Mineral and Geoscience Department, Malaysia. The properties investigated were green and fired clay colour, plasticity, green strength, dry and fired shrinkage, porosity, chemical and mineral composition. The properties of the clay revealed that they have geographical IP potential; particularly, the predominantly off-white fired colour of the ball clay at temperature range of 900-1100⁰C can secure an identity for Kelantan ceramics in the local, national or international market. Based on these properties, the ball clay is applicable for table ware, earthenware and local tile production while the mottled clay has a potential use for vitrified clay pipe, local tile and brick production.

Abstract: This paper outlines a finite element procedure for predicting the mechanical behaviour under bending of sandwich panels consisting of aluminium skins and aluminium honeycomb core. To achieve a rapid and accurate stress analysis, the sandwich panels have been modelled using shell elements for the skins and the core. Sandwich panels were modelled by a three-dimensional finite element model implemented in Abaqus/Standard. By this model the influence of the components on the behaviour of the sandwich panel under bending load was evaluated. Numerical characterization of the sandwich structure, is confronted to both experimental and homogenization technique results.

Abstract: This paper presents a study on the effect of alkali treatment of Oil Palm Kernel Shell (OPKS) on the mechanical properties ofpolyester composite. The dosage of NaOH in this study is limited to 5wt% concentration.The experiments on mechanical properties investigate the tensile strength, the flexural strength and theflextural modulus of untreated, cold alkali treated and hot alkali treated OPKS reinforced polyester composite. It is found that the alkali treatment improves the mechanical properties of the composite. However, the improvement due tothe hot alkali treatment is significant compared to the cold alkali treatment. The morphology of OPKS and the fracture surface of OPKS composites were investigated using scanning electron microscopy (SEM), showing a rough surface and good interfacial adhesion between OPKS as filler and polyester as a matrix.

Abstract: In the recent years there has been an intensification of policies on sustainable construction materials in the construction industry. This environmental policy has brought about development of various sustainable materials in which Petrovege blocks is one of the outstanding products. This paper investigates the effect of curing age on the compressive strength of the product. Block samples were prepared by adding 8%, 9%, 10%, 11%, 12%, and 13% liquid content of the mixture of vegetable oil and crude oil sludge as a binder after the optimum liquid content has been established. The specimens were cured at different period of time of 48hrs, 72hrs, 96hrs, and 120hrs. Mechanical properties of the products were evaluated. Compressive strength of Petrovege samples varies from 5.31 N/mm² to 18.88 N/mm² indicating that the compressive strength increases with increase in curing age, while decrease in porosity leads to increased compressive strength for the stipulated curing ages. All samples satisfied the minimum requirements in terms of compressive strength, in accordance with all available standards.

Abstract: This paper evaluates the effects of yawing misalignment contact on the tooth root bending stress values of spur gear pair during the gear meshing cycle. A model basedon involute 3DparametricCAD geometry, of spur gear design ISO 6336:2006 is analyzed with worst loading position when yawing misalignment (Y) exist due to assembly error (AE) between 0.2⁰ to 0.4⁰ in degree scale values. Finite-element method (FEM) with dynamics module from ANSYS is used in order to calculate the tooth root bending stress (TRBS) at the critical region with respect to face width of pinion and gear section. A comparison is made between standard high point single tooth contactmodels (HPSTC) to this model as verification. Further analysis showeda good agreement that these methodologies are adequate in order to conduct a real time dynamics simulation to define the value of TRBS in Y condition due to AE. Yawingmisalignment influence factor (YMIF) was introduced as an indication of TRBS values in consideration of Y due to AEshows a higher result for pinion, give a good justification that the pinion is weaker compared to the gear in Y condition.

Abstract: Twist Morphing (TM) wing is one of biomimetic MAV design that highly depends on morphing force actuation. Despite of vital morphing force influenced, the effect of morphing force variation on the aerodynamic performances of TM wing was not fully comprehended due to high complexity of fluid-structure interaction (FSI) behaviour. To elucidate the effect of morphing force influence, a series of TM wing with different morphing force intensity was used here to elucidate the effect of morphing force on C_L, C_D, and C_M distribution. Fully coupled Ansys-FSI method was employed in this study. C_L and C_M results showed that TM wing with higher morphing force configuration had induced better static stability and higher C_L distribution. However, TM wing also promoted earlier AOA_stall incidence and higher C_D penalty than the baseline wings. These situations turn out to be greater in the TM wing cases with higher morphing force configurations.