Komponen mesin dapat diproduksi dengan variasi metode manufaktur seperti, penempaan, permesinan, pengecoran, atau metode pengelasan. Pemilihan metode manufaktur berdasarkan biaya produksi untuk setiap bagian pada komponen tertentu. Friction welding sebagai proses produksi masal merupakan metode manufaktur yang diminati untuk penggabungan dua material. Proses friction welding pada baja AISI 1045 dilakukan dengan menggesekkan kedua permukaan baja. Variasi waktu gesek yang digunakan yaitu 25, 35, 45, dan 55 detik kemudian dilakukan pengujian tarik, kekerasan, dan metalografi. Kekuatan tarik tertinggi yaitu 703,84 N/mm2 pada waktu gesek 45 detik. Kekerasan yang terbaik didapat pada waktu gesek 55 detik dengan nilai kekerasan 270 BHN. Struktur kristal dengan butiran halus akan menghambat dislokasi, sehingga mendapatkan sifat mekanik baja yang baik.

No abstract

3D printing technology or additive manufacturing is manufacturing by adding materials to objects until it is shaped as expected. This technique is easy and cheap for printing polymer-based materials in the form of filament. Recently, some metal-containing filament has been introduced in the market, one of which is eSteel composed of 45% wt. steel and 55% wt. PLA. Due to its premature introduction, it is a minimal published paper discussing its mechanical properties and dimensional accuracy. This research aims to analyze the dimensional accuracy of 3D printed products of the fused deposition modeling (FDM) technique using eSteel filament. Taguchi method was used to design the experiments with orthogonal array L4 (23). There were three control parameters with two levels each, namely extruder temperature (220°C, 225°C), layer height (0.3 mm, 0.4 mm), and raster angle (0°/90°, 45°/45°). These parameters were selected based on initial trials. The specimens are in the form of an ASTM D790 flexural test with five replications in each combination. HE3D K200 3D printing machine was used for printing the filament. Analysis of variance indicated that raster angle has the most influence on dimensional accuracy by 32.09%, followed by extruder temperature with a contribution of 31.72% and layer height by 25.53%. The combination of control parameters to produce optimal dimensional accuracy was obtained when combining parameters: extruder temperature of 220°C, layer height of 0.3 mm, and raster angle of 0°/90°.

The engine movement mechanism is a system composed of machine elements that contact or rub against each other between these surfaces. Surfaces that rub against each other will cause a friction force that causes wear on the surface, so it requires energy to fight the friction force. Lubricants are needed to reduce friction and reduce wear rates, where lubricants are generally made of mineral materials. Lubricants made from synthetic materials are non-renewable and cause environmental problems. The development of biolubricants as lubricating materials based on animal fats or vegetable oils is continuously being carried out. This study aims to observe the potential of biolubricants based on reviews from various previous research journals. The use of additives in biolubricants is also studied whether the addition of these additives can improve the characteristics of biolubricants. This study shows that the addition of certain additives to biolubricants can improve the characteristics of biolubricants.

Wind energy has been developed and used as a source of electrical energy by converting wind energy into electrical energy using a generator. There are some wind turbine parameters that important for wind turbines design and model, includes the size of the rotor radius, airfoil selection, chord length, and pitch angle. The study aims to characterize the performance of a horizontal axis wind turbine using computational methods. The methods used a design and simulation of NACA 4412 and NACA 4712 airfoil using QBlade software using wind conditions in the region of Pancer, Jember. Results show that the maximum Cl value of NACA 4712 is higher than in NACA 4412. NACA 4712 has a maximum Cl value = 1.696 at α = 14 o while NACA 4412 airfoil has a maximum value of Cl = 1.628 at α = 15 o. NACA 4712 has the maximum value of Cl/Cd = 153 at α = 2 o , while the NACA 4412 has a maximum value of Cl/Cd = 133.5 at α = 5.5 o. The maximum value of Cl/Cd 4712 is higher than the NACA 4412. At 7.66 m/s of wind speed with 10% turbulence conditions, wind turbines with NACA 4712 airfoil have Cp turbine performance parameters of 0.49929 and obtain a power of 1.15 kW, while wind turbines with NACA 4412 have Cp turbine performance parameters of 0.395365 and obtained power of 0.889 kW at the same wind speed.