Engineering Science and Materials Commons^™

การประยุกต์ใช้แผ่นที่ปรับค่าความแข็งด้วยลมเข้ากับมือจับแบบง่าย, เจตนิพิฐ อรุณรัตน์

Chulalongkorn University Theses and Dissertations (Chula ETD)

จากแนวคิดการใช้งานผิวหนังเทียมหรืออุปกรณ์ห่อหุ้มเพื่อเพิ่มความปลอดภัยและประสิทธิภาพในการทำงานของหุ่นยนต์ นำมาสู่การพัฒนาผิวหนังเทียมที่ติดตั้งบริเวณมือจับของหุ่นยนต์ โดยผิวหนังเทียมเหล่านี้จะมีค่าความแข็งที่แตกต่างกันตามการใช้งาน วิทยานิพนธ์เล่มนี้นำเสนอการออกแบบและขึ้นรูปแผ่นที่ปรับค่าความแข็งได้ (VSPs) ด้วยความดันลม ซึ่งทำหน้าที่เสมือนเป็นผิวหนังเทียมของมือจับ จากนั้นนำแผ่นดังกล่าวไปทดลองใช้กับมือจับแข็งเกร็งอย่างง่าย เพื่อหยิบจับวัตถุซึ่งไม่ทราบตำแหน่ง รูปทรงและความแข็งที่แน่ชัดด้วยวิธีการควบคุมอิมพีแดนซ์ VSPs สร้างขึ้นจากวัสดุอ่อนนุ่มประเภทซิลิโคน ซึ่งขึ้นรูปโดยใช้การหล่อและเสริมความแข็งแรงด้วยเส้นใยไฟเบอร์ มีโครงสร้างภายในเป็นทรงกระบอกเรียงตัวขนานกัน สามารถควบคุมค่าความแข็งผ่านการควบคุมค่าความดันโดยใช้ปั๊มเข็มฉีดยาร่วมกับตัวควบคุมแผนเลื่อน จากการทดลองประยุกต์ใช้ VSPs ร่วมกับมือจับแข็งเกร็งพบว่า VSPs ช่วยเพิ่มความปลอดภัยและความยืดหยุ่นในการทำงาน เนื่องจากสามารถปรับค่าความแข็งให้เหมาะสมกับการทำงานนั้น ๆ ได้ โดยการปรับค่าความแข็งเพิ่มจะช่วยลดระยะเวลาในการทำงาน หากลดค่าความแข็งจะช่วยเพิ่มความปลอดภัยและความเสถียรในการทำงานแทน

การระบายความร้อนของเเผ่นเรียบด้วยโครงสร้างเชือกดูดซับน้ำ, ชลธิชา แกล้วทนงค์

Chulalongkorn University Theses and Dissertations (Chula ETD)

การศึกษาครั้งนี้มีวัตถุประสงค์เพื่อศึกษาการประยุกต์อุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์ งานวิจัยนี้ได้แบ่งการศึกษาออกเป็น 2 ส่วนด้วยกันคือ การศึกษาส่วนแรกเป็นการทดสอบผลของอุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์จำลอง และการศึกษาในส่วนที่ 2 เป็นการเสนอการประยุกต์อุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์ ซึ่งได้นำเสนอต้นแบบการประยุกต์อุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์โดยมี 3 รูปแบบ รูปแบบที่ 1 คือกรณีติดตั้งบนดาดฟ้าอาคารเรียบโดยใช้ระบบน้ำร่วมกับอาคาร รูปแบบที่ 2 คือกรณีติดตั้งบนดาดฟ้าอาคารเรียบโดยแยกระบบน้ำกับอาคาร และรูปแบบที่ 3 คือกรณีติดตั้งบนหลังคาที่มีความลาดเอียงโดยแยกระบบน้ำกับอาคาร และวิเคราะห์ความคุ้มค่าทางเศรษฐศาสตร์ โดยวิเคราะห์มูลค่าปัจจุบันสุทธิ (NPV) อัตราผลตอบแทนภายใน (IRR) วิเคราะห์ระยะเวลาคืนทุน (Payback Period) และวิเคราะห์ความอ่อนไหวของโครงการ การทดสอบอุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์จำลองแสดงให้เห็นว่าสำหรับกรณีฟลักซ์ความร้อน 205.8, 483.8 และ 661.8 W/m2 สามารถลดอุณหภูมิของแผงได้ถึง 5.9, 8.3 และ 11.3°C ซึ่งประมาณได้เป็นการเพิ่มประสิทธิภาพเซลล์แสงอาทิตย์ 2.95, 4.15 และ 5.65% ตามลำดับ และผลการวิเคราะห์ความคุ้มค่าทางเศรษฐศาสตร์ของประยุกต์อุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์ตัวอย่างที่ขนาดการติดตั้ง 6.6 kW ตลอดอายุโครงการ 25 ปี แสดงให้เห็นว่าการติดตั้งในรูปแบบที่ 1 คือกรณีติดตั้งบนดาดฟ้าอาคารเรียบโดยใช้ระบบน้ำร่วมกับอาคาร มีค่า NPV สูงสุด IRR มากสุด และระยะเวลาคืนทุนน้อยสุด ได้แก่ 109,112.11 บาท, 255.33% และ 0.39 ปี ตามลำดับ ในการวิเคราะห์ความอ่อนไหวโครงการที่พิจารณาผลกระทบจากการเปลี่ยนแปลงค่าไฟฟ้า ค่าน้ำ และค่าผลกระทบของอุณหภูมิต่อประสิทธิภาพเซลล์แสงอาทิตย์ พบว่า ค่าผลกระทบของอุณหภูมิต่อประสิทธิภาพที่เปลี่ยนไปส่งผลต่อ NPV, IRR และระยะเวลาคืนทุนมากที่สุด โดยที่การเปลี่ยนแปลงค่าน้ำมีผลกระทบน้อยที่สุด

A Numerical Study Of Flow Past Arrays Of Cylinders At Low Reynolds Number, Woraphon Wannaviroj

Chulalongkorn University Theses and Dissertations (Chula ETD)

Coastal erosion along shorelines has increasingly been prevalent. A popular method for alleviating this problem is to use breakwaters, made of bamboo, known as “bamboo fencing”. The thesis numerically investigates steady, low-velocity flow past several geometrical configurations of bamboo fencings, modelled as array of cylinders using the ANSYS®-Fluent software. The Reynolds number based on incoming flow velocity (U∞), cylinder diameter (D), and fluid kinematic viscosity is Re = 100. Validation is done for mesh convergence and time-step size for the two-dimensional flow past a circular cylinder. For a pair of side-by-side arranged cylinders, it is found that the effect of …

Using Machine Learning To Interpret Dice Rolls, Hunter Wimsatt, Aarohi Panzade, Kaaustaaub Shankar, Warren Campbell

SEAS Faculty Publications

Gamers use polyhedral dice that come with 4 sides (D4), 6 sides (D6), 8 sides (D8), 10 sides (D10), 12 sides (D12) and 20 sides (D20). All dice are unfair, some more than others. The goal of this project was to develop a machine learning and computer vision solution for the interpretation of dice rolls. When combined with an automated dice roller it would facilitate the study of dice unfairness. In the machine learning literature, Convolutional Neural Networks (CNNs) are the preferred method of computer classification of images. The CNN convolves images with different weights and biases through multiple layers …

Preperitoneal Insufflation Pressure Of The Abdominal Wall In A Porcine Model, Riley E. Reynolds, Benjamin Wankum, Sean J. Crimmins, Mark A. Carlson, Benjamin S. Terry

Department of Mechanical and Materials Engineering: Faculty Publications

Background Most complications and adverse events during laparoscopic surgery occur during initial entry into the peritoneal cavity. Among them, preperitoneal insufflation occurs when the insufflation needle is incorrectly placed, and the abdominal wall is insufflated. The objective of this study was to find a range for static pressure which is low enough to allow placement of a Veress needle into the peritoneal space without causing preperitoneal insufflation, yet high enough to separate abdominal viscera from the parietal peritoneum.

Methods A pressure test was performed on twelve fresh porcine carcasses to determine the minimum preperitoneal insufflation pressure and the minimum initial …

Lightning Strike Response Of Composite Structures: A Review, Akhileshwar Pandey, Ashutosh Kumar Upadhyay, Karunesh Kumar Shukla

Journal of Metals, Materials and Minerals

Wind turbines and aircraft are generally made of less conductive carbon/glass composites. Significant damages may occur to these materials if they are struck by high energy lightning strikes. Damage and structural response of composites is essentially a multiphysics domain, involving thermal, electrical, magnetic and structural analysis. In this article, the fundamental physics of lightning, multiphysics analysis, numerical implementation and experimental studies about composite materials are reviewed. The relevant international standards and possible characterization methods of lightning strike damage are also reproduced in this article. In addition to this, the current and prospective technologies, to protect composite from lightning strikes are …

Wear Behavior Of Aluminium 6061 Alloy Reinforced With Coated/Uncoated Multiwalled Carbon Nanotube And Graphene, Vijee Kumar, Kempaiah Ujjaini Nagegowda, Satish Babu Boppana, Ramesh Sengottuvelu, Palanikumar Kayaroganam

Journal of Metals, Materials and Minerals

The current study deals with the fabrication and investigation of wear characteristics of Aluminium 6061(Al6061) hybrid metal matrix composites (MMCs) processed through powder metallurgy technique. Al6061 hybrid MMCs involving fixed 2 wt% of coated/uncoated multiwalled carbon nanotubes (MWCNTs) and varying weight percentages of graphene were fabricated through ball milling procedure. To enhance the scattering of MWCNTs in the matrix, MWCNTs were coated by means of copper through electroless deposition method. Dry sliding wear conduct of Al6061 MMCs was investigated using a pin-on-disc wear testing machine. It was found that at lower load, composites exhibited lower wear resistance than base alloy …

Improvement On Cost-Performance Ratio Of Fiberglass/Carbon Fiber Hybrid Composite, Nathawat Poopakdee, Warut Thammawichai

Journal of Metals, Materials and Minerals

Fiberglass composite (FG) is widely used as a metal substitute in general applications due to its corrosion and chemical resistance, relatively high strength, and low cost. Still, the FG is deficient in performance and relatively heavy for airframes. Carbon fiber composite (CF) is utilized instead as it has greater performance and lower weight. However, the CF is brittle and expensive. Thus, in this work, we combine FG and CF into two types of hybrid composites to achieve a cost-effective solution with greater or comparable mechanical properties to those of CF. The first one uses FG as core and CF as …

Efficiency Of Tri-N-Octylamine For The Liquid-Liquid Extraction Of Co (Ii) From Acidic Chloride Medium, Aishwarya Mishra, Nilam Swain, Sanghamitra Pradhan, Sujata Mishra

Journal of Metals, Materials and Minerals

Cobalt criticality is increasing as a function of time and this concern has impelled researchers to ascertain efficient recovery schemes of cobalt. In this paper, an extraction strategy for cobalt utilizing tri-n-octyl amine (TOA) in kerosene from acidic chloride media has been developed. The extraction percentage was found to be 76.7 using 1.5M TOA. The extracted species has been formulated as (R3NH) CoCl3 based on the findings of slope analysis. Influence of various salting out agents like NH4Cl, KCl, and NaCl on the percentage extraction has been analysed and KCl emerged as beneficial for extraction. The estimated values of enthalpy …

Microstructure And Properties Of Zirconia-Alumina Composites Fabricated Via Powder Injection Molding, Nalattaporn Saelee, Nutthita Chuankrerkkul, Panitarn Wanakamol

Journal of Metals, Materials and Minerals

This study aimed to fabricate zirconia-alumina composites via powder injection molding and investigated the effects of alumina addition on microstructure as well as physical properties of the composites. Zirconia-alumina composites were prepared using polyethylene glycol (PEG) and polyvinyl butyral (PVB) as binders.  The powder loading was fixed at 38 vol%, and PEG: PVB binder weight ratio was fixed at 80:20.  Alumina content within ceramic component was varied at 0, 10, 20, 30, 40 and 50 vol% to observe the effect of alumina on the composite structures and properties. The injection molding was done at 190℃ followed by water debinding of …

Enhancing Stability And Antioxidant Efficacy Of Fisetin By Encapsulating As Β-Cyclodextrin Inclusion Complex With Porous Polylactic Acid Film From Breath Figure, Charasphat Preuksarattanawut, Warinyupa Mangmee, Munchumas Prousoontorn, Ekasit Nisarattanaporn, Krisana Siraleartmukul

Journal of Metals, Materials and Minerals

This research aims to investigate the scope of fisetin (FIT)/β-cyclodextrin (β-CD) inclusion complexes with the ratios of 1:2 and 2:1 mole by means of freeze-drying, kneading and physical mixing methods (controlled process). Moreover, the complex compounds are analyzed by Fourier-Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). The results show that the most suitable preparation method of fisetin (FIT)/β-CD complex is the freeze-drying method with the fisetin (FIT) to β-CD ratio at 1:2. The emission of FIT/β-CD was investigated and it is found that the emission rate of freeze-dried FIT/β-CD in 1:2 ratio by freeze-drying method is lower than …

Study Of Mechanical Properties And Characteristics Of Eco-Fibres For Sustainable Children's Clothing, Siti Shukhaila Shaharuddin, Marzie Hatef Jalil, Kaveh Moghadasi

Journal of Metals, Materials and Minerals

The aim of this paper is to study the application of eco-fibres as a new approach to achieve the multifunctional design for children’s clothing toward sustainability in the clothing industry. In this regard, this study focuses on the evaluation of the fabrics’ mechanical properties including tensile strength and microstructural details as critical points for multifunctional children's clothing purposes. The eco-fibre fabrics studied are organic cotton twill and recycled polyester. Studies have proven that frequent laundering and dry-cleaning result in increased pilling. Furthermore, high quality of colour fastness properties was found in 100% organic woven cotton fabric and recycled polyester fabric …

Effect Of Micro Graphite Particles On The Microstructure And Mechanical Behavior Of Aluminium 6061 (Al-Mg-Si) Alloy Composites Developed By Novel Two Step Casting Technique, Madeva Nagaral, Raghavendra Pai K., V. Auradi, Bharath V., Shanawaz Patil, Mahantesh S. Tattimani

Journal of Metals, Materials and Minerals

In the present research, the effect of micron sized graphite addition on the microstructure and tensile failure of Al6061 alloy has been studied. The Al6061 alloy metal matrix composites reinforced with 6, 9 and 12 varying weight percentages of graphite particles were fabricated by novel two step stir cast route which helps in improving the wettability of Al6061 alloy matrix with graphite particles. The synthesized composites were subjected to microstructural studies, density, hardness and tensile properties testing. Microstructural characterizations of obtained samples were carried out by SEM microscopy, EDS and XRD patterns. The occurrence of graphite particles were confirmed by …

Sustainable Valorization Of Sugarcane Leaves For Succinic Acid And Biochar Production, Nuttaporn Chokesawatanakit, Pasakorn Jutakridsada, Khanita Kamwilaisak

Journal of Metals, Materials and Minerals

The leaves of sugarcane (Saccharum officinarum) are agricultural waste that is burnt before harvesting. This project aims to find an alternative way to increase the value of sugarcane leaves and decrease air pollution by using the leaves as raw material to produce succinic acid and biochar. Reducing sugars were extracted from the leaves by H2SO4 hydrolysis. The sugars were then fermented by Yarrowia lipolytica TBRC 4417 to produce succinic acid. The solid residue was used as the raw material for biochar production by pyrolysis. The effects of pyrolysis temperature (350, 400, and 450℃) and nitrogen gas flow rate (5, 10, …

Assessment Of Hydrothermal Parameters On Alkaline Activation Of Fly Ashes Using A Central Composite Design, Ivan Supelano García, César Armando Ortíz Otálora, Carlos Arturo Parra Vargas, Julieth Alexandr Mejía Gómez

Journal of Metals, Materials and Minerals

Coal fly ash (CFA) is a powder generated during combustion of coal; its improper disposal constitutes an environmental issue. To minimize this problem, one of the uses of CFA is as feedstock for production of zeolite. Different studies have shown that zeolites may be easily obtained from CFA by relatively cheap and fast conversion processes. Most of these studies have been focused on the study of the zeolite synthesis using classical methods through changing one factor per time and fixing the other factors, where it illustrates the impact of each variable individually via a huge number of experiments, however it …

Debinding Behaviour And Sintering Temperature-Dependent Features Of Coloured Zirconia Fabricated By Ceramic Injection Moulding, Wantanee Buggakupta, Thanakorn Wasanapiarnpong, Nutthita Chuankrerkkul

Journal of Metals, Materials and Minerals

Zirconia (ZrO2) is one of ceramic materials that has very good mechanical and chemical properties suitable for biomedical applications as well as other industrial applications. ZrO2 ceramics, in fact, has been used in orthodontic dentistry. Nowadays, ZrO2 has been played its role in decorative and jewelry purposes, such as watchcases and artificial stones. Ceramic injection moulding (CIM), a near-net shape manufacturing process that can produce small, complex-shaped components and is suitable for large volume production, is one of the best powder fabrication methods. In this work, CIM was carried out in order to form the coloured-ZrO2 specimens. Binders used in …

Effects Of Annealing Treatment On Microstructure And Hardness In The 28 Wt% Cr Cast Iron With Mo/W Addition, Kittikhun Ruangchai, Ruangdaj Tongsri, John Thomas Harry Pearce, Torranin Chairuangsri, Amporn Wiengmoon

Journal of Metals, Materials and Minerals

In this study, the effects of annealing on the hardness and microstructure of 28 wt% Cr-2.6 wt% C iron with 1.4 wt% Mo/1 wt% W addition have been investigated. The as-cast samples were heated to 800℃ and held for 4 h followed by slow cooled with a cooling rate of 20℃h-1 to 500℃. Microstructures were characterized by X-ray diffractometry, optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Vickers macro-hardness and micro-hardness were measured. It was found that the as-cast microstructure in the hypoeutectic 28 wt% Cr iron without Mo or W addition consisted of primary austenite dendrite, eutectic M7C3 …

Mechanical Properties And Ionic Conductivity Of Biodegradable Materials In Solid Polymer Electrolyte, Fatin Arhana Awang, Mohd Faiz Hassan, Khadijah Hilmun Kamarudin

Journal of Metals, Materials and Minerals

No abstract provided.

Electrochromic Property Of Tungsten Trioxide Films Prepared By Dc Magnetron Sputtering With Oblique Angle Deposition And Thermal Oxidation, Chantana Aiempanakit, Areeya Chanachai, Nattaya Kanchai, Montri Aiempanaki, Kamon Aiempanakit

Journal of Metals, Materials and Minerals

In this work, WO3 thin films were prepared in two steps: First, tungsten (W) films with thickness of 100-300 nm were deposited by DC magnetron sputtering with oblique angle deposition (OAD) technique at 0 and 85. Second, sputtered W films were annealed under air atmosphere at a temperature of 500℃ and different oxidation times for 1-3 h. The structure of WO3 thin films were examined by X-ray diffraction and field emission scanning electron microscope. In addition, the optical and electrochromic properties of the WO3 thin films were measured by a spectrophotometer before and after testing in potassium hydroxide electrolytes. The …

Improvement Of Alkali Resistance Of Glass Fiber From Basalt And Lignite Bottom Ash Mixture By Addition Of Zro2 Content, Apirat Theerapapvisetpong, Phraethong Kwanpanngam, Thanapat Tamrongwongwi

Journal of Metals, Materials and Minerals

No abstract provided.

New Views On The Ingenious Applications Of Ag Nanoparticles As A Sensor For Antibiotic Detection And As A Potent Antimicrobial Agent, Keyur Bhatt, Anita Kongor, Mohd Atharb, Vinod Jain

Journal of Metals, Materials and Minerals

Nanotechnology uses exceptional approaches for the control of bacterial infections which uncovers the potential function of bio-systems at nano-scale level. Compared to silver ions, silver nanoparticles possess enhanced physicochemical stability and low bio-toxicity properties. The intrinsic chemical framework of silver nanoparticles is prone to exhibit a significant chemistry when used as sensor and as therapeutic. Nowadays, silver is used in (nano-) medicine, in the form of nanoparticles to optimize its therapeutic property for controlling infections caused by multidrug-resistant bacteria. Exclusive use of antibiotics as medicines and its discharge from the body of the infected person or animals into the sewage …

Investigations On Phase Coexistence And Functional Properties Of Bczt Lead-Free Piezoceramic, Jirapa Tangsritrakul, Thiyanee Sonkami, Chumpon Wichittanakom, Chotiros Dokkhan, Panithi Wiroonpochit

Journal of Metals, Materials and Minerals

Large piezoelectric properties was observed in (1-x)BZT-(x)BCT where x=0.5 or Ba0.85Ca0.15Ti0.9Zr0.1O3 (denoted as BCZT), leading to a promising candidate for lead-free piezoelectric materials. However, phase formation of the BCZT is controversial and still unclear since various phase coexistences were identified in the literatures, for instances, the mixed phases of rhombohedral-tetragonal (R-T), ortho-rhombic-tetragonal (O-T) or rhombohedral-orthorhombic-tetragonal (R-O-T). Additionally, it is well known that the crystal structure plays a crucial role on the occurrence of polarization in the piezoceramics. Therefore, this work aims to investigate the coexistence of phase formation at room temperature for the BCZT powder and ceramic. Moreover, the electrical …

Influence Of Precursor Preparation On The Synthesis Of Boron Carbide From Glutinous Rice Flour, Kannigar Dateraksa, Sujarinee Sinchai

Journal of Metals, Materials and Minerals

Boron carbide is a promising candidate for a variety of applications, including blasting nozzles, neutron moderators, and lightweight armor. Using of inexpensive and readily available starting materials which can react with boric acid to form B-O-C bonds, e.g., glutinous rice flour, is one of alternative means to produce high purity boron carbide powder at low temperature. In this study, boric acid and glutinous rice flour, boron and carbon sources, were used for synthesizing B4C powder by the carbothermic reduction. The mole ratios of boric acid to glutinous rice flour ranging from 1:1 to 2.5:1 were formulated and mixed by continuous …

Effect Of Zinc-Hydroxo Species On The Growth Of One-Dimensional Zno Nanostructures, Nontakoch Siriphongsapak, Somyod Denchitcharoen

Journal of Metals, Materials and Minerals

One-dimensional ZnO nanostructures were grown on ZnO seed layer by hydrothermal method using zinc nitrate (Zn(NO3)2) and sodium hydroxide (NaOH) as precursors. The concentrations of NaOH and Zn(NO3)2 were varied from 40 mM to 680 mM and kept constant, respectively. Effects of increasing the hydroxide ions on the concentration of zinc-hydroxo species in the solution were studied using thermodynamic simulation software. The simulated results showed that Zn(OH)2 and Zn(OH)3- concentrations tended to decrease but Zn(OH)42- was non-linearly increased when the concentration of NaOH at room temperature was increased. After the growth of ZnO, the samples were characterized by FESEM and …

Experimental And Numerical Characterization Of Fatigue Crack Propagation In High-Speed Railway Wheel Er8 Steel, Chaichayo Suetrong, Vitoon Uthaisangsuk

Journal of Metals, Materials and Minerals

In this work, characteristics of fatigue crack growth in the Paris regime of the rail wheel steel grade ER8 were investigated. Experimental crack growth tests under different cyclic loads of a compact tension (CT) specimen and corresponding FE simulations were carried out. The extended FE method (XFEM) coupled with damage evolution based on the strain energy release rate or the Paris law was applied to describe the crack propagation mechanism in the tested CT samples. Hereby, the fatigue fracture model parameters were firstly determined from the experimental data. It was found that the predicted crack growth rates agreed well with …

Effect Of Cladding Of Stellite-6 Filler Wire On The Surface Of Ss316l Alloy Through Cold Metal Arc Transfer Process, Thinesh Babu Thiagarajan, Sengottuvel Ponnusamy

Journal of Metals, Materials and Minerals

In this work, Cladding was done on SS316L alloy through the CMT process using Stellite-6 filler wire. 31 experiments were done at different welding conditions as per CCD matrix. The cladding specimens were characterized by macro and micro-study, Vickers microhardness evaluation and corrosion resistance analysis. An optical microscope, SEM-EDAX, and XRD were used to predict the structural characterizations, presence and the distributions of the elements. Based on the study higher voltage & welding speed showed appreciable hardness at the interface & cladding regions. The thickness of the interface was noted at a maximum of 190 μm. The EDS spectra showed …

Development And Characterization Of Sic Fiber Reinforced B4c Composite, Jitendra Kumar Sonber, Sanjib Majumdar, Vivekanand Kain

Journal of Metals, Materials and Minerals

This study is conducted to investigate the effects of silicon carbide short fiber (SiCf) reinforcement on processing and properties of boron carbide ceramic. Studies have been carried out on the hot pressing, mechanical property measurement, microstructure evolution and oxidation study of SiCf reinforced B4C composite. B4C-SiCf composites have been prepared by hot pressing at 1950℃ with varying SiCf content in the range of 10 vol% to 30 vol%. All the composites are densified to near theoretical density. It is noticed that hardness of composite is decreased and fracture toughness of composite is increased by addition of SiC fiber. Hardness of …

Facile Purification Of Locally Mined Gypsum And Its Use For Preparing Nano-Hemihydrates, Luqman Ayodeji Adams, Enobong Essien, Taiwo Aiyeloro, Stella Oseyomon, John Makanjuola

Journal of Metals, Materials and Minerals

Gypsum has a wide range of applications, in interior decorations, building construction, supplements or implants in orthopaedics to mention a few. However, in many developing countries including Nigeria, there is still a large-scale importation despite huge available natural deposits. In this study, a facile method to purify locally-mined gypsum has been explored based on the mineral retrograde solubility in water. The purified gypsum was investigated for its elemental composition in comparison to the crude sample and a commercially obtained medical-grade gypsum using X-ray fluorescence (XRF). The results showed that the purified gypsum contained 94.05% CaSO4 compared with the crude which …

Efficiency Of 2-Dodecylaminopyridine For The Liquid-Liquid Extraction Of Gold(Iii) From Succinic Acid Medium, Umrao Shep, Rucha Pawar, Balasaheb Arbad

Journal of Metals, Materials and Minerals

Extractive recovery of gold(III) from succinic acid solution with high molecular weight amine: 2-dodecylaminopyridine (2-DDAP) as a new extractant in xylene has been investigated. Extraction data indicates that 5 × 10-4 mol⋅L-1 2-DDAP is a very efficient and fast extractant. Gold(III) can be effectively extracted (D = 414.16) with 2-DDAP from 0.04 M succinic acid solution. The equilibrium of gold(III) from aqueous phase of succinic acid with 2-DDAP is achieved within 60 sec. The extraction of gold(III) with 2-DDAP proceed at the interface according to ion pair formation mechanism. The best stripping solution from among the studied ones is the …

Effect Of Dc Power On The Thickness, Hardness And Adhesion Strength Of Ti-51 At% Ni Coated Ti/Tin, Ishiaka Shaibu Arudi, Esah Hamzah, Muhammad Azizi Mat Yajid, Bushroa Abdul Razak

Journal of Metals, Materials and Minerals

The coating of Ti/TiN was successfully deposited on Ti-51 at% Ni substrates by using direct current (DC) magnetron sputtering technique and the effect of different sputtering power on the thickness, surface hardness and adhesion strength of the coatings were studied. The microstructural characterization was carried out using scanning electron microscope (SEM), energy-dispersive X-ray (EDX) and X-ray diffractometer (XRD). The coating thicknesses were detected and measured using SEM. The surface hardness test was performed using microhardness tester, and the adhesion strength was carried out by scratch testing. The results showed that the TiN crystallites growth orientation, thickness, surface hardness and adhesion …