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Molecular Dynamics Simulations of Iron-Joining Using Copper as a Filler Metal Munaji, Munaji; Buntoro, Ghulam Asrofi; Purniawan, Agung; Arifin, Rizal
Makara Journal of Science Vol. 22, No. 3
Publisher : UI Scholars Hub

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Abstract

The study of theliquid filler metal infiltration on the narrow channel of adjoining metal bears importance in understanding the mechanism of the metal brazing process. In this study, we employed the molecular dynamics simulation to understand the mechanism of Cu liquid infiltration through the narrow channel of Fe slabs. Our simulation showed that the wetting process of Fe surfaces by Cu liquid precedes the infiltration process. This study also revealed that the channel became narrower and blockages were found in the channel due to the deformation of Fe surface. In addition to the effect of viscous drag, this process should also contribute to the decreasing speed of the Cu liquid front.
THE EFFECT OF FILLER ON MORPHOLOGY AND ELEMENTS BIOCOMPOSITE PCL/PLLA/NHA Salsah, Rizka Putri; Purniawan, Agung; Sutarsis, Sutarsis
INFOKUM Vol. 10 No. 5 (2022): December, Computer and Communication
Publisher : Sean Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58471/infokum.v10i5.1123

Abstract

Implants are internal fixators that are implanted into the human body. Implantable materials that have biodegradable properties in recent years. This research aims to make a matrixed biocomposite of a mixture of polycaprolactone (PCL) and poly(l-lactic acid (PLLA) with a modified nano hydroxyapatite (nHA) filler of one of the silane coupling agents, namely 3-aminopropyltriethoxysilane (APTES) and analyze the effect of the addition of PLLA and nHA on morphology and elements. PCL was chosen as a matrix because it has biodegradable, ductile and low degradation rate properties and is mixed with PLLA because it has high biodegradable and mechanical properties but a high degradation rate. So, combining PCL and PLLA can make the mechanical properties of the polymer more optimized and promising for use in bone fixation devices. nHA was chosen because it has bone-like properties and has excellent biocompatibility. The variations used are PCl/PLLA composition ratios of 70:30, 80:20, 90:10 and the addition of nHA modified by APTES with variations of 10, 20, and 30%. The results of the SEM analysis show that with the addition of the percentage of PLLA and nHA 20% get optimal results. EDX results validate the elements or elements contained in the PCL/PLLA/nHA biocomposite.
FeCrMnNiCSi Coating on Grey Cast Iron FC 25 Variable Gas Pressure on Thermal Arc Spray Method Purwaningsih, Hariyati; Putra, Rifqi Tantyo; Raharjo, Slamet; Rochiem, Rochman; Purniawan, Agung
Jurnal ILMU DASAR Vol 19 No 1 (2018)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2693.648 KB) | DOI: 10.19184/jid.v19i1.6339

Abstract

One of the important components of motor fuel engine is cylinder liner. There is a compression and friction combustion process with a piston that produces mechanical energy in cylinder liner. This process introduced several problems that often arise, such as wear reducing because the piston is moving back and forth continuously causing gas leakage so that compression pressure is reduced. To prevent such damage it is necessary to coat the metal with other material that has better wear resistance. This study used FeCrMnNiCSi coating material deposited on Gray cast iron FC 25 by thermal arc spray method to analyze the influence of pressure air variation on morphology and mechanical properties. SEM analysis showed that the higher pressure on the coating process results smaller particles thereby decreasing the porosity. Roughness testing also showed a decrease in the higher pressure, at a pressure of 6 bar of 127.333 μm. Microhardness showed that the 6 bar pressure indicating hardness was 639.8 HV. At 6 bar pressure also obtained the highest abrasion resistance value is 29.66 rotation / mg. The value of adhesion strength in the 4 bar pressure variables shows the optimum value compared with other pressure variations of 15.02 MPa. Keywords: cylinder liner, thermal arc-spray, pressure ambient
PENGARUH REKAYASA PERMUKAAN TERHADAP NILAI KEKERASAN PADUAN MAGNESIUM AZ31 Mu'adz Abdullah Faqih; Purniawan, Agung; Rasyida, Amaliya; Susanti, Diah
MATHunesa: Jurnal Ilmiah Matematika Vol. 13 No. 1 (2025)
Publisher : Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/mathunesa.v13n1.p190-196

Abstract

Paduan magnesium AZ31 menawarkan prospek yang menjanjikan sebagai material implan biodegradable karena memiliki sifat mekanik yang menyerupai tulang manusia dan biokompatibilitasnya yang unggul. Namun, kelemahan utama material ini adalah laju korosi yang tinggi dapat mengakibatkan kegagalan material sebelum regenerasi jaringan selesai dan kekerasan yang rendah sebagai material implan tulang. Penelitian ini bertujuan untuk mengatasi permasalahan tersebut dengan melakukan rekayasa permukaan melalui metode Plasma Electrolytic Oxidation (PEO) dan Hydrothermal Treatment (HT). Studi ini melibatkan tiga spesimen: AZ31 tanpa perlakuan, AZ31 dengan lapisan PEO, dan AZ31 dengan lapisan PEO yang diberi perlakuan HT. Analisis difraksi sinar-X (XRD) menunjukkan pembentukan senyawa MgO, Mg(OH)₂, Mg₂SiO₄, dan hidroksiapatit pada permukaan lapisan. Intensitas puncak hidroksiapatit tertinggi ditemukan pada spesimen yang menjalani perlakuan HT, menandakan peningkatan kandungan hidroksiapatit yang dapat meningkatkan bioaktif implan. Uji kekerasan Vickers menunjukkan bahwa spesimen dengan lapisan PEO memiliki nilai kekerasan tertinggi sebesar 76,69 HV, meningkat 35% dibandingkan dengan spesimen tanpa perlakuan (56,60 HV). Setelah perlakuan HT, kekerasan menurun menjadi 68,94 HV, yang disebabkan oleh relaksasi tegangan internal saat proses hidrotermal. Hasil penelitian ini menunjukkan bahwa kombinasi metode PEO dan HT tidak hanya meningkatkan kekerasan permukaan, tetapi juga menghasilkan lapisan bioaktif dengan potensi biointegrasi yang lebih baik. Kombinasi ini menjadikan paduan AZ31 sebagai kandidat unggul untuk aplikasi implan biomedis. Penelitian lebih lanjut disarankan untuk mengoptimalkan parameter proses dan mengevaluasi kinerja biologis secara in-vitro dan in-vivo guna mendukung pengembangan aplikasi klinis.
The influence of Silane Coupling Agent and porogen ratio on 3D scaffold PCL/HA Faqih, Mu'adz Abdullah; Purniawan, Agung; Rasyida, Amaliya; Susanti, Diah
SINERGI Vol 29, No 3 (2025)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/sinergi.2025.3.016

Abstract

The design of scaffold based on polycaprolactone (PCL) and hydroxyapatite (HA) has attracted attention as a solution for bone tissue regeneration. However, the main challenge in its development is the difficulty in achieving an optimal balance between porosity and mechanical strength. Suboptimal porosity limits the scaffold ability to support cell proliferation, and weak mechanical properties result in the scaffold being less than optimal as a load-bearing implant material during the bone cell regeneration process. This study aims to address these issues by evaluating the effects of the silane coupling agent 3-aminopropyltriethoxysilane (APTES) and the porogen ratio (NaCl) on the mechanical properties, morphology, and biodegradation of PCL-HA-based 3D scaffold. The scaffold were synthesized using the solvent casting/particulate leaching (SCPL) method with varying APTES concentrations (1%, 3%, and 5%) and porogen ratios. (4:1, 6:1, and 8:1). The results of characterization show that the addition of 1% APTES increases compressive strength by 283% and tensile strength by 138% compared to scaffold without APTES. A higher porogen ratio (8:1) results in the highest porosity of 78.16%, but reduces mechanical strength by 84%. The optimal combination was found in scaffold with 1% APTES and a porogen ratio of 4:1, which have optimal mechanical strength, porosity of 69.65%, and a biodegradation time of up to 380 days. This research offers a comprehensive solution to enhance the properties of PCL-HA based 3D scaffold, making a significant contribution to the development of materials for bone tissue engineering applications. 
Synthesis of PLA/PLGA Biocomposite with Variation of Silane Coupling Agent as Reinforcement for Bone Plate Applications Hartanto, Denny; Purniawan, Agung; Sutarsis, Sutarsis
Syntax Literate Jurnal Ilmiah Indonesia
Publisher : Syntax Corporation

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36418/syntax-literate.v10i4.58624

Abstract

This research investigated the synthesis of polylactic acid (PLA) and poly(lactic co-glycolic acid) (PLGA) bio-composites with nano-hydroxyapatite (nHA) fillers for bone plate applications, focusing on the effects of different silane coupling agents and polymer ratios. The research analyzed how various silane coupling agents (3-MPS, APTES, Vinyl Silane) and PLA compositions influenced structural, morphological, mechanical, biodegradation, and biocompatibility properties. Materials were characterized using FTIR, SEM, tensile and compression testing, weight loss analysis, and MTT assay. FTIR confirmed successful nHA surface modification with silane agents through the presence of Si-O-Si and NH2 functional groups. SEM revealed that Vinyl Silane produced samples with fewer voids and better filler distribution, while increased PLGA content resulted in more homogeneous structures. Mechanical testing demonstrated that composites with Vinyl Silane exhibited superior tensile (6.98 MPa) and compressive strength (8.19 MPa), while samples with 20% PLGA content achieved the highest values (7.18 MPa tensile, 8.28 MPa compressive). Biodegradation analysis showed that PPnHA8020-APTS samples achieved optimal degradation time (5.1 months), aligning with bone healing timelines. All bio composites demonstrated cell viability above 80%, exceeding ISO 10993-5 standards, with PPnHA9010-APTS showing the highest biocompatibility (86.76%). The research established that optimized PLA/PLGA/nHA bio composites, particularly with Vinyl Silane coupling agent and 20% PLGA content, offer promising properties for biodegradable bone implant applications, combining adequate mechanical strength with appropriate degradation rates and excellent biocompatibility.
ELECTROCHEMICAL PERFORMANCES OF NITROGEN-DOPED CARBON/MNO2 COMPOSITE SUPERCAPACITOR ELECTRODE IN KI-ADDED NA2SO4 ELECTROLYTE Sutarsis, Sutarsis; Abyan, Demas Muhammad; Kussuma, Fahrul Ardian Firmanda; Pradesar, Yusuf; Purniawan, Agung
Jurnal Dinamika Vokasional Teknik Mesin Vol. 9 No. 2 (2024)
Publisher : Department of Mechanical Engineering Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/dinamika.v9i2.77816

Abstract

In this study, Nitrogen-doped Activated Carbons (NAC) with different Nitrogen concentrations (NAC1, NAC2, NAC3) and Manganese Dioxide (MnO2) were composited to make the hybrid active material for supercapacitor electrodes to improve the energy density of NAC by adding the pseudo-redox capacitive properties of NAC/MnO2 composite electrode. NAC active material was made from the pyrolyzing biomass carbon and Polyaniline mixture at 800 °C in a nitrogen atmosphere for 2 hours. NAC/MnO2 hybrid material was synthesized by heating NAC: MnO2 with a ratio of 5:1 at 400 °C for 2 hours. Peaks analysis of X-ray diffraction of NAC/MnO2 powder shows that the MnO2 phase was formed as a composite with NAC. The electrochemical performance of the NAC3/MnO2 electrode exhibited the highest capacitance of 168 Fg-1 at a scan rate of 5 mVs-1 in Potassium Iodide (KI)-added Na2SO4 electrolyte. According to the Cycle Voltammetry (CV) measurement, the NAC3/MNO2 composite electrode shows hybrid capacitive behavior consisting of pseudo-redox and double-layer electrostatic energy storage mechanisms in KI-added Na2SO4 electrolyte. NAC3/MnO2 composite electrode demonstrates a high energy density of 22 Whkg-1 at 5 mVs-1.