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This study employed advanced statistical techniques to optimize pulse current gas tungsten arc welding orbital parameters on SS316L stainless steel pipes, a unique autogenous welding process. The experiment maintained an average peak current of 100 ± 0.5 A, and analysis of variance assessed the impact of welding parameters on tensile strength, distortion, ovality, tapers, and bead width. Despite a small dataset, the Taguchi technique revealed intricate interactions, identifying optimal settings for maximum tensile strength and minimal distortion. Response surface methodology created area plots, enhancing understanding of parameter-response relationships. The recommended specifications, determined through careful examination, achieved a working cycle of 66.5%, a peak current of 114.7 A, and impressive tensile strength of 661.4 MPa with minimal distortion. Experimental validation confirmed the model's credibility, offering valuable insights for practitioners to enhance welding quality, precision, and efficiency.

In this research, investigation of mechanical properties and microstructure on Pulsatile Current Gas Tungsten Arc Welding (PC-GTAW) was carried out. AISI 304L was chosen as a base material with autogenous welding and butt joint configuration. The dimension of the base material was 120 x 50 mm and the thickness of 3 mm. The welding with pulsatile current and constant current were used in the welding process in this study. In the pulsatile current, the mean current was made all the same with a constant current of 100 amperes. The peak current, base current and time of peak and base current were varied to make it the same. The welding speed used is constant at 2.0 mm/s. The result shows that the HAZ area will get shrinkage if welded using pulsatile current welding. The welding with a pulsatile current can produce more fine cellular dendritic structure than the welding with a constant current. The UTS in the welding with a pulsatile current was lower than the welding with constant current, while the impact toughness in the welding with a pulsatile current was higher than the welding with a constant current. The highest of the UTS and the impact toughness of 577.62 MPa on parameter 65-A and 27 J on parameter 65-C, respectively.

Micro-milling offers high flexibility by producing complex 3D micro-scale products. Weight reduction are one of the optimizations of the product that can make it stronger and more efficient nowadays. Titanium are the most commonly used for micro-scale products especially in biomedical industries because of the biocompatibility properties. Titanium alloys offers high strength with low density and high corrosion resistance that is suitable for weight reduction. This study aims to investigate the influence of high speed cutting parameters to the surface roughness in micromilling of titanium alloy Ti-6Al-4V as high speed cutting offers more productivity since producing more cutting length in the same time. experiments are carried out by micromilling process with variations in high speed cutting parameters of spindle speed and feed rate with a constant depth of cut using a carbide cutting tool of with a diameter of 1 mm. The machining results in the form of a 4 mm slot with a depth as the same as depth of cut, which then measures its surface roughness. It was found that higher feed rate that is followed by higher spindle speed will produce better surface roughness.

Micro products or micro components are commonly used in today’s world. Research around micromanufacture technologies to produce a better product quality has been going on extensively. Ultrasonic vibration assisted micromilling (UVAM) is one of the technologies that can give a better machining qualities over the conventional ones. One of the benefits UVAM can give is reducing the machined surface roughness. The purpose of this paper is to give an idea how vibration assisted micromilling can give a better surface roughness quality. The theoritical surface roughness geometry model is made using MATLAB software. The cutting tool used in the simulation is end mill. There is a feature of the cutting tool called bottom cutting edge angle. This feature will be considered on this paper. The effects of the bottom cutting edge on workpiece machined surface can be looked visually from the simulation. Thus, the effects of cutting process using UVAM on the workpiece surface can be looked as well through the simulation.

Vibration assisted machining (VAM) is a method that is widely used in improving the performance of machined products. External vibrations with high frequency to ultrasonic range along with an meso-micrometer amplitude are given to the cutting tool or workpiece. This will result in a periodic separation phenomenon, hence reducing the cutting force which has positive impacts on increasing tool life and machined surface quality. Among the high-precision machining processes, micro-milling which has the ability to produce complex components with 2D and 3D features, can also be applied with the vibration assisted method, known as vibration assisted micro-milling (VAMM). Based on the direction of vibration given in the machining process, there are 1D VAMM with linear vibrations and 2D VAMM with circular or elliptical trajectory vibrations. However to date, neither developed 1D nor 2D VAMM systems are still limited to the research of planar surfaces cutting using linear movement axes, meanwhile vibration assisted in inclination cutting of micro-milling using the rotational movement axes is still very rare. Therefore the purpose of this paper is to present the preliminary model in designing a 2D VAMM system for a 5-axis micro-milling machine. The system is powered using piezoelectric actuators as the vibration-producing actuators.

The development of micro-products in industry, like aviation, medical equipment, electronics, etc, has been increasing lately. The need for scaling down of product has been increasing to make the product simpler and complex. Micro-milling has capabilities in producing complex parts. In this study, mapping and comparing the result of the machining process of Inconel 718 and Aluminum Alloy 1100 was employed. In this experiment, Inconel 718 was used as workpiece material and the result of Aluminum Alloy taken from recent studies. Then, A cutting tool with a diameter 1 mm carbide coating TiAlN was used in this experiment. The machining process was performed with three varieties of spindle speed and feed rate with a constant depth of cut. After the machining is done, the mapping of the result surface roughness of Inconel 718 and AA1100 performed. It was found that Inconel 718 has poor machinability compared with AA 1100. Inconel 718 also has a high manufacturing cost compared to AA 1100 because the cutting tool was easy to wear.

This paper presents a novel implementation of digital twin (DT) technology in monitoring the wear condition of micro tool (TWM) during micro-milling process. The proposed DT is capable to predict the wear condition of micro tool using electric current data of spindle motor. This minimal setup of the system gives potential benefits for various deployment in real industrial practice. A miniaturized 5-axis micro-milling machine was used in the experiment to perform slot milling in micro-meter level. The proposed DT shows promising result of TCM in micro-milling within Industry 4.0 framework.

Aluminum and stainless steel are metals that have some mechanical property advantages. Welding technology has been developed to join both different and dissimilar metals applied in a construction. The property advantages have been used to improve the performance of a construction. However, welding performance still creates a problem as a result of properties’ differences in metals. This study investigated the mechanical properties of a steel-aluminum joint with the thickness of less than 1 mm, welded by resistance spot welding (RSW); it is called a micro-RSW. Mechanical properties of the joint were analyzed by tensile test and were measured at the fracture area on the tensile test specimen. Moreover, it also analyzed intermetallic microstructure in the nugget or welding joint. Welding time of 8 CT was an optimum parameter on a welding process to get the maximum load. The fractographic structure of a stainless steel-aluminum joint showed a brittle nugget. Moreover, the fracture area on the aluminum side was larger than that of the stainless steel. Intermetallic compound (IMC) was created by melting and joining it through the heat input in the welding process. IMC in SS301-AA1100 nugget affected a brittle joint.

Micro-metal forming that offers solutions for micro-part manufacturing has developed rapidly over many years. In this paper, research clustering on mechanical micro-sheet-metal forming system is described, and a review is presented. Trending research topics in recent years are then discussed. The process forming investigation is more interesting than other aspects, as size effect phenomena at the micro-level influence the quality of the micro-product. It is concluded that more efforts are still needed to fill the gap in developing micro-forming technology to meet the industrial application requirements, especially in producing final products with good quality, which can be achieved only with good material properties, high tooling technology, proper working parameters and sophisticated material handling in precision forming machines. [Submitted 19 December 2017; Accepted 31 May 2018]

Quality of recycled plastic is usually below than its virgin material. Status of quality compared to its virgin material quality helps producers and consumers to ensure viability of the material both as a manufacturing product as well as a raw material. A set of material testing result table accompanied with radar chart of its ratios proposed as a tool in representing quality indicator of a recycled plastic. An easy identification of lower and lowest quality and also better quality in certain material characteristics help producers and consumers to make a fast evaluation and further decision related to recycled plastic quality improvement and its proper utilization as raw material.

Nowadays micro fabrication technology is very varied and being continuously developed. One of them uses bacteria as tools that known as biomachining. Acidithiobacillus ferooxidans is a one of bacteria which can do metal removal as a source of energy. The previous research has proven the ability of Acidithiobacillus ferooxidans for material removal process. In this research, biomachining process was added by angle of inclination parameter to know the effect on copper surface profile and roughness. This method was used to get profile shape result of multi-axis in biomachining. Workpieces were patterned by photolithography method and put in the bacterial culture medium, which was inclined 20° and 30° on inclinator. Profile shape and the surface roughness measurement data were taken by SURFCOM machine. The results of this research showed that by inclining 20° and 30° of biomachining sample produced different profile shapes and surface roughness.

The challenge for engineer’s orthopedic prosthetic rehabilitation is to find a state of the art in the field, technical or otherwise, that will help their clients who have disabilities. Organ replacement with prostheses is one of the most successful procedures until now. However prostheses are still using standard geometry that has been determined by the manufacturer of the prostheses and it becomes a problem. In addition to the design size that does not fit, long manufacturing process takes time and is expensive also being a problem. Suitability of the prostheses with the patient's body anthropometry and speed of production in the manufacture of the prostheses is very important. In manufacturing, precision and speed of manufacture of the product is something that is possible but requires a high cost, especially in the manufacture of prostheses. By using rapid prototyping technology are available, this research try to develop the customized and rapid manufacturing systems for the manufacture of prostheses, especially for Total Knee Replacement (TKR).

Cut geometry data is an essential information in current machining simulation and optimization. The tool orientation changed continuously during free-form machining become a challenge in predicting cut geometry in 5-axis milling. This paper present an extended analytical method to define cut geometry during semi-finish milling. The algorithm was developed by taken into account the existence of helical angle. The developed model was successfully implemented to generate the shape and the length of cut. From the test it was found that helical angle gives significant effect to the cut geometry.

Technology of Friction Stir Welding (FSW) is a relatively new technique for joining metal. In some cases on Aluminum joining, FSW gives better results compared with the arc welding processes, including the quality of welds and less distortion. The purpose of this study is to analyze the parameters effect of high speed tool rotation on micro Friction Stir Spot Welding (μFSSW) to the shear strength of welds. In this case, Aluminum material A1100, with thickness of 0.4 mm was used. Tool material of HSS material was shaped with micro grinding process. The spindle speed was fixed at 30000 rpm. Tool shoulder diameter was 3 mm, and a length of pin was 0.7 mm. The parameter variations used in this study were the variable of pin diameter (1.5 mm, 2.0 mm, and 2.5 mm), a variable of plunge speed (2 mm/min, 4 mm/min, 6 mm/min), and the variable of dwell time (2 seconds, 4 seconds, 6 seconds). Where the variation of these parameters will affect to the mechanical properties of welds (as response) was the shear strength. Response Surface Methods (RSM) was used to analyze μFSSW parameters with the shear strength of welds. From the result of experiment and analysis, it is shown that the important welding parameters in high speed μFSSW process are pin diameter and plunge speed.

It is a phenomenon that an experience mechanical/ design engineer with years of experience in mechanical parts design, still must to improve the knowledge about process design. This phenomenon will be different with other fields but common in process design because design is continuous process. The automotive industry is expected to be one of the driving factors for economic growth in Indonesia in 2025. It is shown by research firm (Frost & Sullivan) that estimates this year's car sales in Indonesia will rise moderately by 6.5% from a year earlier to 948,500 units and the real car sales in Indonesia rose to 43% in April 2012. Development should be increased because the government provides to industrial facilities that conduct research, development and innovation. Therefore the design process until production is expected to be rapid and immediate product can be enjoyed by society. To speed up the production process, the design process should be faster, and account how the next process that is the production. This research useds the form of the usual features carried with three machining processes are widely used in the world of mechanical component industries. The processes are turning (around 24.9% of machining process), milling (around 20.2% of machining process) and drilling (around 28.2% of machining process). The overall mean of the three processes around 73.3% of the portion of the machining process (survey conducted by PERA).

Technology of Friction Stir Welding (FSW) as a technique for joining metal is relatively new. In some cases on Aluminum joining, FSW gives better results compared with the Arc Welding processes, including the quality of welds and less distortion. FSW can even use milling machine or drilling machine, by replacing the tools and the appropriate accessories. The purpose of this study is to analyze the effect of process parameters on micro Friction Stir Lap Welding to the tensile load of welds. In this case, Aluminum material A1100, with thickness of 0.4 mm was used. Tool material of HSS material was shaped with micro grinding process. Tool shoulder diameter was 3 mm, while the diameter pin was 2 mm and a length of pin was 0.7 mm. The parameter variations used in this study were the variable of spindle speed (2300, 2600, and 2900 rpm), variable of tool tilt angle (0, 1, 2 degree) and a variable of Feed rate (50, 60, 70 mm/min). Where the variation of these parameters will affect to the mechanical properties of welds (as response) was the tensile load. Analysis and optimization parameters between the micro FSLW parameters with the tensile load of welds, is used a Response Surface Methods (RSM). From the result of experiment and analysis, it is shown that the important welding parameter in Micro Friction Stir Lap welding process is tilt angle.

This research describes the scope of design and test a traction controller to combine a 6.54 kW gasoline engine power and 2x48VDC/0.5 kW electrical brushless motors in a serial-parallel type of small hybrid electric vehicle. A central control system was designed to operate the engine which is equipped with continuous variable transmission and electric motor on rear wheel side in order to select the optimal torque in normal driving condition. The battery charging system draws its energy from the engine using two alternators: 80 Watt built-in alternator and 300 Watt additional alternator which is driven using a power take-off unit. To increase the electric charging capacity, the electric motor is able to operate as a generator during acceleration or deceleration condition (regenerative system). The static preliminary testing shows that the electric motor can generate about 38% of nominal motors power at 730 rpm of wheel rotation.

Five-axis milling is used in the machining of complex shaped surfaces in a wide range of industries. In five-axis milling, one can adjust inclination angle to adapt such machining condition, e.g. to give high material removal and/or to avoid gouging. Choosing an appropriate inclination angle is difficult especially for complex parts with varying surface curvature. On the one hand, a small inclination angle is recommended to have good surface roughness and small scallop height. On the other hand, some regions may need much larger minimum inclination angle compared to the others to avoid gouging. The trade off for this is to have, in practice, a varying minimum (which is considered to be optimal) inclination angle along the tool path, so that while machining, the tool is dynamically adapted to be as close as possible to the surface without gouging. However, applying inclination angle change over some distances influences the quality of machined surface. This paper presented a method to control such inclination angle change to improve part accuracy. Some experimental were conducted to see the results and compared with the one when inclination angle change is not controled. The propose method effectively reduces the surface deviation thus improve part accuracy. More details about this study are presented in the paper.

The needs of miniaturized products have increased a lot in this ever-changing world. This makes the micromanufacturing technologies develop fast in order to keep up with this higher needs and to meet the required quality of a product. One of the developed technologies is ultrasonic vibration assisted machining (UVAM). UVAM is different than conventional machining because of the way the cutting tool move relative to the workpiece. This different cutting phenomenon produces a different chip geometry than the conventional machining. The purpose of this paper is to give an understanding through chip geometry models about how UVAM can be a better cutting method rather than conventional milling. MATLAB is used in order to do the modelling of theoretical chip geometry. The approach used in this study is by calculating where the cutting tool edge is in a given unit of time before and after the ultrasonic vibration is induced to the workpiece in X-Y dimension. A characteristic in the cutting edge called the bottom cutting edge angle is also considered. By comparing the two chip geometries, some benefits that UVAM gives are explained.

In recent years, the rapid technology development in industry sector, especially in aviation industry has been increasing. So that we need more capabilities in the micro-scale manufacturing process, especially micro-milling process which can produce good surface roughness and high complexity parts. In this study, the effect of machining parameters to the surface roughness investigated by using Inconel 718 material with cutting tool diameter 1 mm, carbide material with coating TiAlN. The machining process was performed in low speed machining category. There are three variations of spindle speed (3.000, 7.000, 10.000 RPM) and also feed rate (0.5, 1, 2 mm/s) with constant depth of cut 10 um. The relationship between machining parameters and surface roughness was obtained. The higher the feed rate, the higher the surface roughness produced. On the other hand, the higher the spindle speed the smaller the surface roughness. It also found that the machining process with low spindle speed, below 10.000 RPM, successfully carried out on hard-to-cut material, Inconel 718, that will be increasing the flexibility of machining parameters.

The demand for micro-scale products is increasing rapidly in various fields of industries such as electronics, bio-medical, optical industry, and so on. Titanium alloys especially Ti-6Al-4V is one of the commonly used in bio-medical industries because of its biocompability properties. However, poor surface quality in terms of surface roughness commonly occurs because of unappropriate cutting parameters to machine this hard to cut material. This study aims to investigate the influencing machining parameters to produce micro-products with a low level of surface roughness in Titanium Alloy (Ti-6Al-4V) material using a miniaturized micro-milling machine. Experiments carried out by micromilling process with variations in low rpm spindle speed and feed rate with a constant depth of cut using a carbide cutting tool of with a diameter of 1 mm. The machining results in the form of a 4 mm slot with a depth of 10 um, which then measures its surface roughness. It was found that as the feed rate increases, the surface roughness also accordingly increases. On the other hand, the surface roughness decreases as the spindle speed increases.

The purpose of this study is to design and develop a Two-Dimensional Ultrasonic Vibration Assisted Micro-milling (2D UVAMM) system. Two-dimensional ultrasonic vibrations produced by 2D UVAMM are used to vibrate the workpiece in the micro-milling process. The system is developed using the principle of two Langevin piezoelectric transducers which have the ability to produce ultrasonic vibrations with small vibration amplitude. Process of 2D UVAMM design optimization was done by modal simulation using Finite Element Analysis method. Both Langevin piezoelectric transducers are designed to have symmetrical and asymmetrical vibration modes with the same natural frequency, so that elliptical pattern vibrations can be generated on the workpiece. The 2D UVAMM system operates at a natural frequency of 24 kHz and has an estimated total displacement on the normal and tangential axes respectively 0.766 um and 0.382 um. Two power sources with frequency of 24 kHz, phase difference of 90 degrees, and peak-peak voltage of 212 volt were supplied by an ultrasonic generator to excite both of the Langevin piezoelectric transducers. To confirm the developed 2D UVAMM system, experiments were conducted to compare the surface roughness of Aluminum 6061-T6 through micro-milling with conventional method and with additional of the 2D UVAMM system.

Sustainable development for machining strategies, process, and technologies, is compulsory in the industries. Machining surface quality improvement and the extension of tool life-time are commonly set as goals by many researchers, in the fulfilment of that sustainable development. Unforeseen and uncontrollable vibration or known as passive vibration is an unavoidable effect and a menace in machining. However in contrary, adding active vibration with stable frequency and amplitude, and small depth of cut during machining, give positive impact toward machine performance and surface quality. Vibration Assisted Machining (VAM) generates active vibration on the tool or workpiece. That vibration repeatedly causes tool-workpiece separation for a period of time during machining. The tool-workpiece separation is the main reason of VAM advancements. Adding VAM to conventional machining requires further consideration in term of design and cutting method, which are investigated in this comprehensive literature review. Critical aspect in adding VAM to micro milling machine was also discussed.

The rough machining is aimed at shaping a workpiece towards to its final form. This process takes up a big proportion of the machining time due to the removal of the bulk material which may affect the total machining time. In certain models, the rough machining has limitations especially on certain surfaces such as turbine blade and impeller. CBV evaluation is one of the concepts which is used to detect of areas admissible in the process of machining. While in the previous research, CBV area detection used a pair of normal vectors, in this research, the writer simplified the process to detect CBV area with a slicing line for each point cloud formed. The simulation resulted in three steps used for this method and they are: 1. Triangulation from CAD design models, 2. Development of CC point from the point cloud, 3. The slicing line method which is used to evaluate each point cloud position (under CBV and outer CBV). The result of this evaluation method can be used as a tool for orientation set-up on each CC point position of feasible areas in rough machining.

The difficulties of tool fabrication in micro level provide an enormous challenge due to the dimension limitation. Reducing the difficulty and tool cost fabrication should always be considered by determining the simplicity of tool geometry, precision tolerance, and an appropriate material selection. This paper study about the manufacturing of micro-blanking punch-die. The mechanical material removal method was chosen to fabricate punch-die since this is a single piece production and intended for small-scale production of micro parts. The manufacturing process consists of punch-die design and fabrication, tool assembly, and clearance measurement. The stress analysis is also conducted to ensure the strength of the punch-die. A micro-blanking experiment was held to observe the tool performance. The result showed that micro-blanking tool can be manufactured successfully and used well to conduct the micro-blanking experiment.