IRANIAN JOURNAL OF MANUFACTURING ENGINEERING
Year:2023 | Volume:10 | Issue:7|Papers Count:6

The results of the research conducted by the researchers have shown that the application of electric current to the metal during deformation can lead to the improvement of the plasticity of the material. This method is known as forming with the help of electricity. In this article, the electro plastic effect on the strain behavior of a 6061-T6 aluminum alloy sheet has been investigated experimentally through the uniaxial tensile test. For this purpose, tensile test samples were cut from a 6061-T6 aluminum alloy sheet with a thickness of 1 mm according to ASTM E8/E8M standard. Then it was examined in the state of no current and in the intensity of currents of 260, 360 and 460 amperes until the appropriate intensity of current is obtained. The results have shown that at a current intensity of 360 amps, the amount of extension in the sample increases compared to the state without current. In addition, a comparison was made between the results of two square and sinusoidal waveforms and it was shown that the sinusoidal waveform has a greater effect on increasing formability. The on and off time of the pulse was also investigated and it was determined that the maximum extension is created in the off time of 20 ms and the on time of 120 µs. Finally, the sample was annealed and the test was repeated with the obtained parameters. The results showed that by applying an electric pulse with appropriate parameters, the formability of 6061-T6 aluminum samples is improved by 23%.

Polymeric foams are of great importance due to their special features such as lightweight, heat, and sound insulation properties. Also, production of polymeric foams saves the consumption of materials due to the use of less raw materials. As a result, it reduces the pollution in the environment. Researchers have shown that by increasing the cell density and decreasing the cell size, better properties of polymeric foams can be achieved. It is accessible by increasing the pressure drop rate of the system with changes in the geometry of the extrusion mold. In this research, the effect of mold geometry, including mold diameter, was assessed on the structural properties of polyethylene foams produced by the physical foam extrusion method with carbon dioxide foaming agent at a process temperature of 130 °C and 2 wt% of nucleating agent. The diameter of the mold was set at 1, 2, and 3 mm to create different pressure drop rates. The results showed that the decrease in the diameter of the nozzle caused an increase in the system pressure. This increase of 1 mm resulted in the system pressure prevailing over the gas injection pressure and caused insufficient gas to enter the system. In the sample with a 2 mm, the pressure of the gas entering the system was higher and the expansion was about 2.25 times, which is more than the 1 and 3 mm molds.

This research is focused on the examination of laser and its application in additive manufacturing. Additive manufacturing is a process in which a three-dimensional model is manufactured layer by layer and from the bottom up. Advances in this powerful and promising process have resulted in a rise in the demand for its applications in the industry. However, controlling the geometry of the deposited material throughout the additive manufacturing process remains a significant challenge. Geometric control and correspondence with the target geometry are key subjects in the additive manufacturing process. This research aims to obtain geometric data of the three-dimensional profile in deposition using the Direct Energy Deposition (DED) method. By imaging the interface of a laser line and the surface of the coating and extracting the resulting line using image processing methods, the profile of one section of the coating is obtained. By applying the same steps to all of the coating's sections and stacking the images, a three-dimensional profile of the coating's profile is constructed. By checking the correspondence between the proposed algorithm's output image and a microscopic image of the same section, the accuracy of this method is assessed. The result of the comparison between these two images indicates an error of 0.29 mm in width and -0.07 mm in height, falling within the range of error defined by ISO guidelines.

Nowadays, Aluminum alloys are chosen for various industrial applications due to their special properties and high corrosion resistance. By optimizing the surface properties of Aluminum alloys, the performance and reliability of using these materials can be effectively improved. Therefore, investigating the surface mechanical treatment has been the focus of researchers and various mechanical methods have been used to improve the surface characteristics of Aluminum alloys. Among these methods, ultrasonic hammer peening is a cold work process in which many impacts are applied to the surface of the sample in a short period with high frequency. In this research, the effect of ultrasonic hammer peening on the wear properties of Aluminum alloy Al6061-T6 has been investigated. To carry out the process of ultrasonic hammering, three parameters of vibration amplitude, rotational speed of the work piece, and feed rate of the tool were selected and their effect on the wear resistance was investigated. The obtained results showed that the ultrasonic hammer peening increased the surface hardness by about 141.4%. With the increase of the vibration amplitude and the feed rate, the wear resistance increased and the increase of the rotational speed decreased the wear resistance. The highest wear resistance has been obtained in the vibration amplitude of 11 µm, rotational speed of 500 rpm, and feed rate of 0.8 mm/rev. As a result, the wear resistance has increased by about 46% compared to the raw material in these conditions.

In this article, a new sensor is presented that measures the shear stress based on the phase difference. In this method, first, using a spring, the force resulting from the shear stress is converted into displacement, and then the displacement is measured. The basis of displacement measurement is the induction of current between two flat coils that are opposite each other. One of these coils is fixed and the other is movable. Each step that the moving coil moves on the fixed coil, its output voltage changes its phase by 2 V Because the resulting phase difference is proportional to the displacement, the amount of movement of the moving coil can be obtained from the measurement of the phase difference. Based on this, a two-dimensional sensor has been designed and simulated that can measure in both x and y directions. The simulation has been done mechanically-magnetically, that is, for moving the electrodes, the output phase difference has been obtained separately in both x and y directions.

Today, micro fluidic devices offer the potential to automate a wide range of chemical and biological operations used for diagnostic and therapeutic applications. In the micro-fluidics, the micro-pump is an essential equipment to control the micro volume of fluid in scale of micro-liter , so the development of the micro-pump has recently received much attention.Many research work are being developed in the field of micro-fluidic devises, which are used in various fields such as biology, chemistry, and clinical medicine. In micro-fluidic applications, the most important elements is declared to the micro-pump. Micro pumps play a key role in these applications. Recently, the design and construction of micro pumps have been developed and various types of these pumps have been designed, and the most important challenges of these pumps are cost,, injection/suction accuracy, and the uniformity of movement. In this research, a syringe micro-pump is designed and manufactured. In addition, the kinematic algorithm of movement with constant acceleration is thoroughly explained. One of the achievements of this pump is high accuracy in injection and uniformity in movement, which creates a uniform flow in fluid injection.