Muhammad Waziz Wildan

Universitas Gadjah Mada | UGM · Department of Mechanical and Industrial Engineering

This study aims to determine the effect of the sintering temperature of nanosilica on physical, mechanical, dielectric, and output voltage properties. The nanosilica particles used in this experiment were produced using the alkaline fusion method from natural sand. The green bodies were uniaxially formed with a pressure of 75 MPa and then were pres...

In this work, the composite filaments containing different cellulose nanocrystals (CNCs) were successfully fabricated by using a single screw extruder and used to 3D print. The influence of CNCs contents (0, 0.75, 1, and 2 wt%) on the properties of the filaments and 3D printed samples were evaluated. The properties of the filaments and 3D printed s...

Generally, glass fiber-reinforced polymer composites are made in the form of laminated composites. Due to the weak adhesion between the fiber and the polymer matrix, failure in the form of delamination often occurs. To overcome delamination, the incorporation of very low content of nanomaterials has been considered. The effect of cellulose nanofibe...

Hydroxyapatite/zirconia (HAp/ZrO2) composites have been developed for potential application in tooth crown. The aim of this analysis is to examine and evaluate the compressive strength, Vickers hardness, and the diametral tensile strength of different HAp/ZrO2 compositions. Physical observation and characterization were also performed in this study...

Pada proses pengelasan dalam kondisi pipa dengan aliran dan tekanan didalamnya (in-service welding) ada dua risiko yang perlu dipertimbangkan yaitu burnthrough di mana busur pengelasan menyebabkan dinding pipa terbuka sehingga isi pipa dapat keluar dan yang berikutnya adalah retak hidrogen yaitu terjadinya retak pada daerah Heat Affected Zone (HAZ)...

Cellulose nanocrystal (CNC)-reinforced bio-composite films containing glycerol were produced using the solution casting technique. The influences of the addition of CNC (2, 4, and 8 wt%) and glycerol (10, 20, and 30 wt%) on the properties of the bio-composite films were studied in the present work. The resulting films were characterized by X-ray di...

Cellulose nanocrystals (CNCs) were isolated from ramie fibers through chemical pretreatments accompanied by sulfuric acid hydrolysis. The influences of both temperature and hydrolysis time on the properties of CNCs were discussed in the present study. The characterization of CNCs was conducted using FT-IR, XRD, TEM, and TGA. The results showed the...

The present study investigates the structural, crystallinity index, crystallite size, morphological, and the dimension of Nanocrystalline Cellulose (NCC) extracted from ramie fiber by hydrochloric acid-hydrolysis. NCC was chosen because it has high strength and modulus compared to other natural materials. Ramie fiber was chosen because it has high...

Nanocrystalline Cellulose (NCC) is a nano-sized material produced by the removal of amorphous regions on cellulose fibers through acid hydrolysis. In recent years, NCC has gained increasing attention because it has superior properties such as high strength, high modulus, high surface area and biocompatible. In the present study, sulphuric acid hydr...

Nanocrystalline cellulose (NCC) is today’s one of rapidly growing nanocomposite reinforcing materials. This is thanks to some advantages that come with it over anorganic nanocomposite reinforcing materials, for example, nanoclay, nanosilica, nanoalumina, carbon nanotubes, among others. Some of the advantages of NCC are environment-friendliness due...

Porous ceramics are a form of ceramic material with widespread applications, such as filters, isolators, and acoustics. This research aimed to investigate the compressive strength and thermal conductivity of porous mullite ceramics (3Al2O3.2SiO2 or Si2Al6O13) produced using dry yeast powder as a PFA (pore-forming agent). Kaolin powder (Al2O3.2SiO4....

The extraction of microfibers from plant fibers can be obtained through specialized, expensive equipment that demands high energy input but delivering low production yields, resulting in highly costly microfibers. This situation confines the use of cellulose microfibers to the laboratory and not for industrial applications. The goal of this study i...

PRODUCTION OF URANIUM−MOLYBDENUM ALLOY AS A CANDIDATE FOR NUCLEAR RESEARCH REACTOR FUEL. Research and development on high density uranium for nuclear research reactor fuel is still in progress. Uranium-molybdenum alloy is one of the strongest candidates of nuclear research reactor fuel material. The properties and characteristics of U-Mo alloy is o...

Ceramic magnets with the chemical composition of barium hexaferrite (BaFe12O19) were obtained through the synthesis of magnetite powder from iron sand taken from the Southern Coast of Yogyakarta in Indonesia. The iron sand was dissolved and then synthesized to produce magnetite powder. Subsequently, the magnetite powder was oxidized at temperatures...

Nanoparticles of magnetite (Fe3O4) are synthesized by co-precipitation in an aqueous solution containing ferrous and ferric salts from dissolved iron sand. Subsequently, the synthesis process is assisted by mechanical vibrations through various frequencies of (0, 100, 200 and 500 Hz). It is found that various frequencies of mechanical vibration upo...

The aim of this research is to optimize of stir casting process parameters to minimize the specific wear of Al-SiC composites by Taguchi method. Composite material used in this research was Al- Si aluminum alloy as the matrix and SiC (silicon carbide) particles size 400 mesh as the reinforcement. Experimental design used L16 orthogonal arrays Taguc...

Pengaruh gaya sentrifugal pada pengecoran sentrifugal adalah mampu menghasilkan coran yang lebih padat dan beberapa sifat yang unggul lainnya dibanding pengecoran konvensional. Tetapi kelemahannya adalah distribusi ketebalan dan kepadatan coran cenderung tidak merata, segregasi dan struktur yang tidak homogen akibat laju pembekuan yang tidak seraga...

The objective of this research is to optimize the process parameters of stir casting by Taguchi method for maximizing the hardness of Al-SiC composites. Composite materials used Al-Si alloy as matrix and SiC (silicon carbide) particles of 400 mesh size as reinforcement agent. Experimental parameters were SiC content, melting temperature of the matr...

Tujuan penelitian ini adalah untuk menganalisis pengaruh kandungan SiC, temperatur cairan, kecepatan putar dan durasi waktu pengadukan pada kekuatan tarik komposit Al-SiC menggunakan metode Taguchi. Material komposit yang digunakan adalah aluminium paduan Al-Si sebagai matrik dan partikel SiC (silicon carbide) ukuran -400 mesh sebagai penguat. Spes...

This study prepared porous hydroxyapatite (porous HA) as synthetic scaffold and find out chemical properties, porosity, compressive strength and cytotoxicity properties. Porous HA was prepared by powder deposition and sintering from HA-PMMA mixed powder. Porous HA characterizations were conducted by XRD, XRF, SEM-EDX and mercury porosimetry analysi...

The clay-reinforced epoxy nanocomposite was prepared by the polymerization method. The effect of clay addition on the mechanical properties of epoxy/clay nanocomposites was studied through tensile, flexural, impact strength, and fracture toughness tests. The morphology and tribology behavior of epoxy/clay nanocomposites were determined by X-ray dif...

The demand of magnets increases with the increasing development of electronic industry in Indonesia, but it was still imported from abroad. While the magnetic materials as iron oxide are quite a lot in Indonesia, one of deposits area of iron sand is Southern coast of Bantul Yogyakarta. The sand contained of the mineral magnetic, these minerals were...

In the present study, hydroxyapatite was synthesized from local gypsum by microwave-hydrothermal method. Different percentage amounts of zirconia (0, 20, 30 and 40 wt.%) and poly-methyl methacrylate (40, 50 and 60 wt.%) mixed with hydroxyapatite (HA) for six hours. These powder mixture were deposited using deposition machine to produce specimens. T...

A novel process for increasing β-SiC yield on solid state reaction of coal fly ash and micro powder activated carbon powder has been proposed. β-SiC powder was synthesized at temperature 1300°C for 2 h under vacuum condition with 1 l/min argon flow. Cycling synthesis process has been developed for increasing β-SiC yield on solid state reaction of c...

The bending strength of composite made from fly ash and glass waste can be improved by controlling chemical composition of the raw materials and sintering temperatures. In this study, the composites made from mixture of various weight fractions between fly ash (FA) and glass waste (GL). Each mixture was uni-axially pressed with various compacting p...

The addition of fly ash into aluminum as reinforcement can potentially reduce the production cost and density of aluminum. However, mechanical properties of aluminum matrix composite reinforced by fly ash (MMC ALFA) have some limitations due to the characteristic of fly ash. In this study, a carbothermal reduction process of fly ash and activated c...

Fly ash particles are potentially used in metal matrix composites, since they are low-cost, low-density and available in large quantities as a waste by-product in thermal power plants. The addition of fly ash into aluminum as reinforcement can potentially reduce the production cost and density of aluminum. However, mechanical properties of fly ash...

This research aims to investigate mechanical properties of aluminum matrix composites reinforced with fly ash (AMC/Fly ash) produced using hot extrusion.AMC/Fly ash was prepared from aluminum fine powder as matrix and fly ash as reinforcement. The various amount of fly ash of 5%; 7.5%; 10%; 12.5% and 15% wt were added to the aluminum fine powder. E...

This research aims to utilize fly ash which is obtained from waste of combustion of coal in steam power plant as a reinforcement of aluminum matrix composite (AMC). The amounts of fly ash of 2.5%, 5%, 7.5% and 10% wt were added to fine aluminum powder (dimension of particles are smaller than 40 µm). Each composition was mixed using a rotary mixer f...

On the sintering characteristic of hydroxyapatite (HA), the resulting microstructure and properties are influenced not only by the characteristic and impurities of materials but also are found to be dependent on the thermal history during the fabrication process. This research is concerned with the effect of sintering temperature on the relative de...

The production of natural hydroxyapatite (HAp) specifically from cortical bovine bones and natural calcite was studied in this paper. Bovine hydroxyapatite (BHA) was produced from bovine bone in bulk form by de-fatting continued with calcination at 900°C. Natural calcite hydroxyapatite (CHA) was produced by hydrothermal method. It was confirmed fro...

The production of hydroxyapatite (HA) from bovine bones was studied in this paper. Bovine hydroxyapatite (BHA) was produced from bovine bone powders by calcination without compaction. The powders were calcined at temperatures ranging from 700–1100°C. It was discovered that sample preparation has some influence on the calcination behavior of the bov...

The production of natural hydroxyapatite (HA) especially from cortical bovine bones and natural gypsum were studied in this paper. Bovine hydroxyapatite (BHA) was produced from bovine bone in bulk form by defating process continued with calcination at temperature 900 degree C. Natural gypsum hydroxyapatite (GHA) was produced using hydrothermal meth...

The behaviour of commercial zirconia ceramics containing metal particles is of interest in the development of anodes for solid oxide fuel cells. The present work describes a study of zirconia reinforced with iron, chromium and stainless steel particles in which the electrical and thermal conductivity have been measured. Both of these properties inc...

Hydroxyapatite (HA) based biomaterials are being increasingly used as bone substitutes in dentistry and in reconstructive and orthopedic applications because of their good biocompatibility, osteoconductivity and/or bone-bonding properties. In this study, cytotoxicity of the hydroxyapatite synthesized from local gypsum (HA-KP) and HA-200 (Waco,Japan...