ARMATUR : Artikel Teknik Mesin & Manufaktur

Effect of Sputtering Time Variation on Mechanical Characteristics and Microstructural Evolution of AISI 4140 Steel

2026-04-27T12:24:02+07:00

AISI 4140 steel is a high‑strength, low‑alloy material commonly used in mechanical components subjected to high load and friction. Although its bulk properties are favorable, surface modification is often required to enhance wear resistance and prolong service life. This study investigates the influence of DC sputtering Titanium Nitride (TiN) deposition time on the mechanical performance and microstructural evolution of AISI 4140 steel. The experimental procedure varied sputtering times at 30, 60, 90, 120, and 150 minutes while maintaining constant processing parameters. Characterization techniques included Vickers hardness testing, wear testing, and SEM–EDX analysis to evaluate coating morphology and coating–substrate interface quality. The results indicate that TiN deposition significantly enhances surface hardness compared to the uncoated substrate. The maximum hardness value of 186.66 VHN was achieved at 60 minutes of deposition, corresponding to a dense, uniform coating with strong adhesion. Prolonged deposition times, however, led to decreased hardness and increased wear rate, attributed to excessive coating thickness, microstructural non-uniformity, and the formation of micro-defects. SEM observations corroborate these findings by revealing notable variations in coating morphology and interface integrity across deposition durations. Overall, the study concludes that sputtering time is a critical parameter in optimizing TiN coatings to improve the surface performance of AISI 4140 steel for engineering applications.

The Analysis of the effect of coating thickness and type on the adhesive strength of SA 516 Gr 70 steel plates

2026-05-04T00:33:59+07:00

SA 516 Gr 70 carbon steel is often used in pressure vessels, requiring a coating system with good adhesive strength to prevent failure due to corrosion. This study analyzes the effect of coating type and thickness on the adhesive strength of SA 516 Gr 70 plates using the pull-off test method in accordance with ASTM D4541. The two coating systems tested were Interbond 2340 (UPC) and Interline 399, with variations in dry film thickness (DFT) of 75 µm, 125 µm, and 175 µm. Surface preparation was carried out through an abrasive blasting process with a cleanliness level of Sa 2½, accompanied by control of roughness profile, salt contamination, dust cleanliness, and control of application environmental conditions to maintain coating quality. Test results show that Interbond 2340 produces higher adhesion values than Interline 399 across all thickness variations, confirming the influence of coating type on coating adhesion performance. A maximum adhesion value of 17.09 MPa was obtained for Interbond 2340 with a thickness of 125 µm, indicating the optimal thickness for increasing the bond strength of the coating to the steel substrate. All specimens met the ASTM D4541 requirements, with Interbond 2340 at a thickness of 125 µm showing the most superior adhesion performance and can be used as a technical reference in selecting a coating system for pressure vessel applications.

Analisis Sifat Mekanik Uji Tarik Material Komposit Serat Karbon–Epoksi 1011l dengan Metode Manufaktur yang Berbeda

2026-05-05T12:02:56+07:00

Carbon fiber reinforced polymer composites are widely used in structural applications due to their high strength-to-weight ratio. Manufacturing methods significantly affect fiber impregnation quality, void content, and mechanical properties. This study investigates the effect of different manufacturing methods on the tensile properties of carbon fiber–epoxy 1011L composites with 0° fiber orientation. Three manufacturing methods were used: hand lay-up (HLU), vacuum bagging (VB), and vacuum assisted resin infusion (VARI). A total of 21 specimens were tested using a Universal Testing Machine (UTM) at the National Research and Innovation Agency (BRIN) following ASTM D3039. The results show that The VARI method showed the best mechanical performance with an average maximum point stress (MPS) of 774,31 MPa and an elastic modulus (ME) of 39.313 MPa, followed by the vacuum bagging and hand lay-up methods. The hand lay-up method produced the lowest MPS and ME values, at 507,72 MPa and 20.401 MPa, respectively. The VARI method produces the best mechanical properties compared to the hand lay-up and vacuum bagging methods.

Evaluasi Kinerja Cooling Tower Tipe Counter Flow Mechanical Induced Draft pada Pembangkit Listrik Tenaga Panas Bumi (Studi Kasus: PT Pertamina Geothermal Energy (Tbk), Area Ulubelu, Unit 4)

2026-05-04T10:48:59+07:00

The cooling tower is one of the vital components in a Geothermal Power Plant (PLTP) system, functioning to cool the condensate water from the condenser before it is reused. This study aims to analyze the effectiveness of a counter flow mechanical induced draft cooling tower at PLTP Unit 4, PT Pertamina Geothermal Energy (Tbk), Ulubelu Area. The data were obtained from field measurements conducted over seven days at fourtime intervals each day. The parameters analyzed include range, approach, and effectiveness, calculated using inlet water temperature, outlet water temperature, and wet bulb temperature. The results show an average effectiveness value of 70.05%, with variations influenced by changes in range and approach values. This effectiveness is close to the design standards stated in the manufacturer’s specifications, indicating that the cooling tower operates with good performance. This analysis provides an overview of the actual equipment condition and can serve as a reference for maintenance and performance optimization in the future.

Studi komparatif variasi ketebalan pelat baja ASTM A36 main steel sebagai penopang baterai torpedo

2026-05-05T12:06:40+07:00

This simulation aims to conduct a comparative study of the thickness variations of ASTM A36 steel plates to determine the most optimal thickness for supporting the weight of torpedo batteries. The analysis focuses on the values of the von Mises stress, displacement, and safety factor parameters. Mechanical engineering in the field of maritime defense is an important aspect, one of which is torpedoes that use battery energy as their main energy source. The battery support is the main focus of this study, which will compare the optimal thickness variations for the battery. With the development of technology and the demands of manufacturing digitalization, the production process has begun to use simulations on Computer-Aided Engineering (CAE) software, making conventional testing more efficient. Through SolidWorks software simulation, a static study was conducted to analyze each variation. ASTM A36 steel plates measuring 1400 mm in length, 70.6 mm in width, and varying thicknesses of 1 mm, 2 mm, and 3 mm were adjusted to the weight of the battery. A total of three 5 kg battery blocks were used in this torpedo. ASTM A36 material was selected due to its high yield strength. The optimal strength of the battery holder was achieved through simulation in SolidWorks. The results of each thickness variation were then processed using a comparative study to obtain the optimal thickness based on a comparison of von Mises stress, displacement, and safety factor.

Perancangan Ulang Produk Kruk Dengan Metode Quality Function Deployment Untuk Memenuhi Kebutuhan Penyandang Disabilitas Kaki

2026-05-12T09:17:43+07:00

The population of persons with disabilities in Indonesia is currently estimated at approximately 22.97 million individuals, representing around 8.5% of the national population. Among this group, persons with lower-limb disabilities constitute the largest proportion, accounting for roughly 38% of all individuals with disabilities. This category of disability is frequently associated with significant challenges in mobility, including difficulties in walking, ascending stairs, and performing other related movements. Consequently, lower-limb disability users commonly depend on assistive devices such as crutches to support their daily activities. However, complaints often arise when using crutches, one of which is the difficulty of using crutches when traveling, whether by motorcycle or car, due to the elongated size of the device. To address these issues, a Quality Function Deployment (QFD) approach was employed to redesign the crutch in accordance with user needs. Based on this study, improvements were made in two aspects: economic and ergonomic. The product was adjusted to ensure that the price is acceptable to users. In addition, a redesign of the crutch dimensions was carried out, resulting in an increase in height. This modification aims to enhance ergonomic comfort and prevent potential secondary health problems for the users

Analisis Hidrodinamika dan Karakteristik Pressure Drop pada Fotobioreaktor Flat-Panel Sistem Closed-Loop Menggunakan Computational Fluid Dynamics

2026-05-18T09:40:21+07:00

Hydrodynamic performance plays a crucial role in determining flow distribution and hydraulic losses inside flat-panel photobioreaktor systems. This study aims to investigate the flow characteristics and pressure drop behavior of a closed-loop flat-panel photobioreaktor using a Computational Fluid Dynamics (CFD) approach. A three-dimensional steady and incompressible laminar model was employed with water as the working fluid. Inlet velocities of 0.01 m/s, 0.03 m/s, 0.05 m/s, and 0.1 m/s were applied to evaluate their influence on velocity distribution, streamline patterns, and pressure drop. A grid independence study was conducted using three mesh densities, and the final mesh with an element size of 0.015 m showed less than 1% variation in pressure drop, confirming mesh-independent results. The simulation results indicate that increasing inlet velocity significantly increases pressure drop and maximum velocity within the reaktor due to flow acceleration near the inlet region. Streamline analysis reveals the formation of recirculation zones in the lower section of panel.