Article Per Year (5 Year)
p-Index From 2021 - 2026
1.197
P-Index
This Author published in this journals
All Journal Proceedings Series on Physical & Formal Sciences Jurnal Ilmiah Teknik dan Sains (JITS) Konstruksi: Publikasi Ilmu Teknik, Perencanaan Tata Ruang dan Teknik Sipil Manufaktur: Publikasi Sub Rumpun Ilmu Keteknikan Industri Venus: Jurnal Publikasi Rumpun Ilmu Teknik Scientific Contributions Oil and Gas Jurnal Kendali Teknik dan Sains
Venty Lestari
Universitas Sriwijaya
Aerospace Engineering Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Electrical & Electronics Engineering Energy Engineering Mechanical Engineering

Published : 7 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 7 Documents
Search

 1 
Karakterisasi Komposisi Kimia dan Homogenitas Paduan Al–Mg–Si Hasil Squeeze Casting untuk Aplikasi Pertambangan Venty Lestari
Jurnal Ilmiah Teknik dan Sains Vol. 3 No. 2 (2025): Desember: Jurnal Ilmiah Teknik dan Sains (JITS)
Publisher : Lembaga Penelitian dan Pengabdian Masyarakat AKIPBA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62278/jits.v3i2.80

Abstract

Paduan aluminium Al-Mg-Si dikenal sebagai material struktural ringan dengan ketahanan korosi yang tinggi dan kemampuan penguatan melalui mekanisme presipitasi. Penelitian ini bertujuan untuk menganalisis komposisi kimia aktual serta implikasi metalurgi dari paduan Al–Mg-Si yang diproduksi menggunakan metode squeeze casting. Proses pengecoran dilakukan pada temperatur peleburan 850 °C, temperatur cetakan 300 °C, dan tekanan 76 MPa selama 10 menit, kemudian dilakukan perlakuan homogenisasi. Pengujian komposisi kimia menggunakan metode Optical Emission Spectroscopy (OES) dilakukan pada dua titik sampel (atas dan bawah) untuk menilai keseragaman distribusi unsur. Hasil analisis menunjukkan bahwa kandungan Mg (1,06%) dan Si (0,63%) berada dalam rentang nilai yang ditargetkan, menandakan tingkat homogenitas yang baik. Kandungan unsur pengotor seperti Fe, Cu, dan Mn berada di bawah 0,1 %, yang mengindikasikan rendahnya risiko pembentukan fasa intermetalik getas seperti Al₅FeSi. Komposisi ini memungkinkan terbentuknya fasa Mg₂Si sebagai presipitat penguat utama dan memberikan stabilitas mikrostruktur yang diperlukan untuk aplikasi struktural. Dengan karakteristik tersebut, paduan ini berpotensi diterapkan pada aplikasi struktural di lingkungan ekstrem, seperti industri pertambangan, di mana dibutuhkan material yang ringan, tahan korosi, dan memiliki kestabilan mekanik jangka panjang. Hasil penelitian ini diharapkan dapat menjadi dasar bagi pengembangan paduan aluminium melalui teknik squeeze casting untuk memenuhi kebutuhan material pada sistem monitoring tambang, casing instrumen, serta komponen ringan di lingkungan kerja yang ekstrem.
Optimalisasi Deformasi Canai Dingin untuk Meningkatkan Sifat Mekanik Paduan Al-Mg-Si Venty Lestari
Venus: Jurnal Publikasi Rumpun Ilmu Teknik  Vol. 3 No. 5 (2025): Venus: Jurnal Publikasi Rumpun Ilmu Teknik
Publisher : Asosiasi Riset Ilmu Teknik Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61132/venus.v3i5.1216

Abstract

The demand for lightweight materials with high mechanical strength has driven the development of aluminum alloys, particularly Al-Mg-Si, through deformation processes such as cold rolling. This study aims to analyze the effect of varying degrees of cold rolling deformation on the grain aspect ratio and macrohardness of homogenized Al-Mg-Si alloys. Deformation was applied at three thickness reduction levels—5%, 10%, and 20%—followed by microstructural characterization using optical microscopy and macrohardness testing in accordance with ASTM E-18 standards. The results show that increasing deformation levels lead to elongated grain morphology, with the grain aspect ratio rising from 1.16 to 2.07 and macrohardness increasing from 46.64 HRE to 62 HRE. The emergence of slip lines and grain flattening indicates the occurrence of intense plastic deformation, while work hardening results from dislocation accumulation that impedes further slip motion. These findings confirm a strong correlation between microstructural evolution and mechanical property enhancement in cold-deformed Al-Mg-Si alloys. This research contributes to the optimization of cold rolling parameters to produce engineering materials with a desirable balance of strength, formability, and fatigue resistance for applications in the mining and heavy manufacturing industries.
Karakterisasi Struktur Mikro dan Sifat Mekanik Paduan Al-Mg-Si Hasil Squeeze Casting Setelah Perlakuan Homogenisasi Lestari, Venty
Manufaktur: Publikasi Sub Rumpun Ilmu Keteknikan Industri Vol. 3 No. 3 (2025): Manufaktur : Publikasi Sub Rumpun Ilmu Keteknikan Industri
Publisher : Asosiasi Riset Ilmu Teknik Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61132/manufaktur.v3i3.1192

Abstract

Al–Mg–Si aluminum alloys are widely utilized in engineering applications due to their low density, excellent corrosion resistance, and mechanical properties that can be modified through heat treatment. This study investigates the effect of homogenization on the microstructure and hardness of Al–Mg–Si alloys produced by the squeeze casting process. The experimental procedure involved alloy melting, squeeze casting at 76 MPa using preheated metal molds, followed by homogenization at 400 °C for 4 hours. Microstructural characterization was performed using optical microscopy to examine the dendritic morphology and measure the secondary dendrite arm spacing (SDAS). Mechanical properties were evaluated through Vickers microhardness and Rockwell macrohardness testing. The results show that homogenization increases the SDAS from 32.59 μm to 36.88 μm and decreases the volume fraction of interdendritic phases from 15.51% to 13.57%. Furthermore, microhardness decreased from 50.22 VHN to 38.58 VHN, while macrohardness decreased from 54.60 HRE to 46.64 HRE. These reductions are attributed to the partial dissolution of Mg₂Si precipitates into the aluminum matrix during homogenization. Overall, this research provides valuable insight into the optimization of initial heat treatment parameters for Al–Mg–Si alloys produced by squeeze casting. The findings highlight the role of homogenization in improving microstructural uniformity and preparing the alloy for subsequent deformation processes such as cold rolling and extrusion, particularly for structural components used in mining and heavy transportation industries.
Impact Assessment of Wax Gelation Fluid Pressure and Temperature: Designing Long-Term Preventive Solutions Hasan, Meutia Fitri; Lestari, Venty; Budiman, Hendra; Setiawan, Aldo; Pamungkas, Mohd Wirawan Putra
Scientific Contributions Oil and Gas Vol 48 No 4 (2025)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/scog.v48i4.1932

Abstract

Paraffinic precipitation presents a pervasive flow challenge, specifically impacting this light crude oil (API 34.85 °) system, particularly within a pipeline (length 1153 m) operating in cold environments. This study first rigorously assessed the critical impact of flow parameters, confirming the fluid’s thermal profile drops below the pour point (31.67 oC) at a crucial distance of 439.24 m from the wellhead, initiating severe wax gelation. Flow analysis further confirms a detrimental laminar flow regime (NRe = 1262), which, coupled with a significant total pressure drop of 0.155 psia/100 ft along the pipeline, exacerbates the tendency for solidified paraffins to accumulate due to insufficient shear stress. To address this, the research successfully validated a cost-effective, long-term preventative solution: a locally fabricated sand heater with an energy capacity of 175,000 kcal/h. Empirical field testing confirmed the intervention provides a substantial net thermal elevation of 8.5 oC. Subsequent thermal modeling for long-term operational reliability identified the optimal sand-heater placement distance to be within 300 m of the wellhead. This strategic placement ensures the fluid temperature consistently remains safely above the pour point, effectively mitigating the risk of premature wax gelation and guaranteeing uninterrupted system integrity and sustained hydrocarbon production.
Pemanfaatan Limbah Pertambangan dan Industri Mineral sebagai Material Geopolimer untuk Aplikasi Konstruksi Tambang Berkelanjutan: Kajian Literatur Berbasis Studi Eksperimental Venty Lestari; Andrawina Andrawina
Konstruksi: Publikasi Ilmu Teknik, Perencanaan Tata Ruang dan Teknik Sipil Vol. 4 No. 3 (2026): Juli: Konstruksi: Publikasi Ilmu Teknik, Perencanaan Tata Ruang dan Teknik Sipi
Publisher : Asosiasi Riset Ilmu Teknik Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61132/konstruksi.v4i3.1467

Abstract

Mining and mineral processing wastes, such as tailings, fly ash, red mud, slag, and coal gangue, have the potential to be utilized as geopolymer materials to support sustainable mine construction. This article aims to review the utilization of mining and mineral processing wastes as geopolymer materials based on experimental research articles. The review was conducted by searching and analyzing 15 research articles that discuss material characteristics, compressive strength, microstructure, reaction products, heavy metal leaching, and the applications of waste-based geopolymers. The findings show that aluminosilicate-based wastes can be used as precursors, substitution materials, fillers, or supporting components in geopolymer systems. Reaction products such as N-A-S-H, C-S-H, and C-A-S-H play an important role in forming the binding matrix, increasing microstructural density, and improving material strength. Waste-based geopolymers also have potential applications as building materials, mortars, road subgrade materials, cemented paste backfill, and hazardous waste stabilization materials. In addition, the geopolymerization process can support heavy metal immobilization through physical encapsulation, chemical binding, adsorption, precipitation, and ion substitution mechanisms. However, its application in Indonesia still requires further studies related to local waste characterization, mix optimization, long-term durability, leaching behavior, technical standards, and economic and environmental feasibility.
Studi Perbandingan Penguatan Paduan Al-Mg-0,5Si Melalui Perlakuan Panas T6, T5, dan T8 untuk Aplikasi Body Kendaraan Taktis Absaralita Sabarati; Teguh Budiyanto; Venty Lestari; Muhammad Pasha Arrighi Effendi; Ariq Fakhri; Fauzan Hasan; Bondan T. Sofyan
Proceedings Series on Physical & Formal Sciences Vol. 9 No. 1 (2026): Seminar Nasional Teknik (SENATEK)
Publisher : UM Purwokerto Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30595/pspfs.v9i1.2172

Abstract

Tactical vehicle bodies require materials with high strength, lightweight properties, and resistance to extreme conditions. This study examined the effects of homogenization, deformation, and artificial ageing on the microstructure, hardness, and potential application of Al-Mg-0.5Si (wt.%) alloy as a tactical vehicle body material. Four different treatments were applied: cold deformation + annealing, T6 (precipitation), T5 (hot deformation + precipitation), and T8 (cold deformation + precipitation). The results showed that homogenization at 400 °C for 4 hours increased the secondary dendrite arm spacing (SDAS) by 13–18% and reduced hardness from 54.6–60.7 HRE (as-cast) to 43.2–53.4 HRE (as-homo). After quenching (as-quenched), the highest hardness was observed in the T5 treatment at 98.5 HRE, followed by T8 (87.6 HRE) and T6 (71.8 HRE). Under peak aging conditions, T5 treatment achieved the highest hardness of 51.16 HRB after 18 hours of aging at 180 °C, while T6 and T8 reached 45.98 HRB and 44.6 HRB, respectively. These differences were attributed to a combination of strengthening mechanisms: strain hardening, grain boundary strengthening, and precipitation hardening, with Mg?Si as the primary precipitate. The Al-Mg-0.5Si alloy with T5 treatment exhibited a higher specific hardness compared to HSLA steel, 18.9 versus 8.5, respectively. With superior mechanical properties and a lighter weight, this alloy showed great potential as a tactical vehicle body material. However, additional tests, such as ballistic and dynamic deformation tests, are necessary for further validation.
Penaksiran Cadangan Batu Gamping Menggunakan Metode Cross Section di Kalirejo, Kulonprogo, Daerah Istimewa Yogyakarta Andrawina Andrawina; Venty Lestari
Jurnal Kendali Teknik dan Sains Vol. 4 No. 2 (2026): April: Jurnal Kendali Teknik dan Sains
Publisher : International Forum of Researchers and Lecturers

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59581/jkts-widyakarya.v4i2.6251

Abstract

Reserve estimation is a critical stage in mine planning that determines the economic feasibility of a mining project. This study aims to estimate the volume and tonnage of limestone reserves in Kalirejo Village, Kulon Progo District, Special Region of Yogyakarta, using the cross section method within a 5 hectare concession area. Primary data were collected through theodolite and GPS measurements, resulting in 29 coordinate points. Three cross sections, namely the red, blue, and pink cross sections, were created based on topographic data processed using ArcGIS. The area of each cross section was calculated using the graphical square method at a scale of 1:2000, where one grid square represents 100 m². The calculated areas were 33,940 m² for the red cross section, 36,645 m² for the blue cross section, and 31,947 m² for the pink cross section. The total reserve volume was calculated using the prismoidal formula, yielding 6,862,853 m³, with an error rate of 0.28% compared to the ArcScene calculation. With a limestone density of 2.5 tons/m³, the total reserve tonnage that can be produced over a 10-year mine life is 17,157,132.625 tons. The stripping ratio value of 0.00305 indicates highly favorable conditions for open-pit mining operations. The production target is set at 1,039,596.65 tons/year, equivalent to 193 tons/hour. This study validates the accuracy of the manual cross-section method combined with GIS software for limestone reserve estimation at the exploration scale.
Co-Authors Absaralita Sabarati Andrawina, Andrawina Ariq Fakhri Bondan T. Sofyan Fauzan Hasan Hasan, Meutia Fitri Hendra Budiman Mohd Wirawan Putra Pamungkas Muhammad Pasha Arrighi Effendi Setiawan, Aldo Teguh Budiyanto