Sand casting is one of manufacturing process that still exist today. Numerous products are produced to serve industrial and domestic use. Defect could lead to product performance, and unfortunately ...inevitable in a casting process. This paper aim to investigate typical defect resulted from sand casting process. An aluminum cooling fan was selected as the model since it has complicated shape with different thicknesses. The casted fan was investigated under photo micro for defect analysis. Porosity, gas inclusion, pinhole, and shrinkage were found as the common defects occured at different part of the fan.
One of the surface treatments to improve the hardness of the surface is by ion implantation process. This paper presents an equation to predict the surface hardness with the variable of the process ...time in ion implantation surface treatment. The hardness of three surfaces data were collected experimentally from various process times, i.e. 140 minutes, 280 minutes and 560 minutes. Lagrange polynomial interpolation was then used to generate quadratic mathematical formula of the surface hardness based on experimental data. The verification results show that the proposed equation accurately predict the surface hardness of commercially pure (cp) titanium under ion implantation process with the error less than 0.5 %. This equation can be used to set the appropriate treatment process time to achieve the expected surface hardness without costly trial experimental settings.
This study explores the geometrical deviations that occur in cold stamping, which are caused by the spring-back effects in elastic metals after forming. The primary aim is to introduce and assess the ...Combination Approach. This approach seamlessly integrates the Displacement Adjustment and Spring Forward methods for die compensation. This multi-stage process meticulously corrects dimensional errors and effectively reduces spring back through iterative processes. Using the NUMISHEET model, numerical simulations have shown a significant reduction in spring back errors, with up to a 55% reduction achieved with optimized die surfaces after five iterations. The proposed Combination Approach improves the accuracy of die design and contributes significantly to the stamping industry by incorporating established techniques within finite element software. This research broadens the scope of die compensation strategies, creating new opportunities for achieving precise die design in stamping.
The objectives of the study is to investigate the formation of intermetallic compound and the mechanical properties of the underwater welding. AISI 4012 steel was selected as the material and two ...types of electrode E6013 and E7018. The variations of electric current used in this study were 80,100, and 120 amperes. The underwater welding was conducted in plain water pool and 3 meters depth by using SMAW. Tensile test and SEM-EDS were carried out to investigate the tensile strength and appearence the intermetallic layer.The results of this study indicated that the highest value of tensile stresswas found on the use E7018 electrodes and 80 amperes electric current. While the lowest value was found in the use E6013 electrodes with 120 amperes. Intermetallic layer was detected base on the SEM-EDS investigation.
Intermetallic systems of Nickel (Ni), Aluminium (Al), and Titanium (Ti) are candidates for lightweight materials that offer high-temperature resistance. Combustion synthesis has been widely studied ...to produce intermetallic and coating deposition by exploiting the heat released by the combustion. An underlayer is often used to enhance the adhesion of the coating to the substrate. The interaction of the coating and the underlayer during heating is, therefore, crucial for achieving a good adhesion quality. This work aimed to investigate the microstructure and properties of the interfacial formation across the NiAl coatings and Ti underlayers formed by combustion synthesis. Induction heating was used to initiate the heating and reaction process with heating rates of 46.6, 57.0, and 85.5 K/s. The microstructure was characterized by Scanning Electron Microscopy (SEM) equipped with an Energy Dispersive Spectroscopy (EDS) detector, whereas the formed phases were identified using X-ray Diffraction (XRD) tests. The hardness distribution was measured by the Vickers microhardness test. The result shows that NiAl with Al-rich and Ni-rich were formed in the coating region. The average thickness of the coating increases by approximately 200, 300, and 400 µm with a heating rate of 46.6, 57.0, and 85.5 K/s, respectively. The different thicknesses of the coating can be attributed to the migration of Ni/Al from the coating to the underlayer zones. The microstructure observed in the underlayer confirms the formation of several intermetallic phases of Ni-Ti and Ti-Al systems. The infiltration of Ni and Al elements from Ni and Al to Ti sides was responsible for generating a reaction between Ni-Ai-Ti. The formation of Ti
2
Ni–Ti
3
Al phases in the underlayer increases with the heating rate. The hardness across the coating, interface, and underlayer increases with the heating rates. The heating rate of 46.6, 57.0, and 85.5 K/s results in the hardness of the interface by 669.1, 804.8, and 967.7 HV, whereas the underlayer increases by 680.1, 772.7, and 978.7 HV, respectively. The increased content of the Ni-Al-Ti system, which are AlNi
2
Ti and Ti
2
Ni–Ti
3
Al phases, was attributed to the increased hardness of the interface and underlayer. This work improves the understanding of second reactions across the interface while fabricating coatings that apply an underlayer.
Purpose
The purpose of this study is to investigate the effect of aging temperature on the barrel-type solder joint lifetime of electronic devices and to include these effects in the modified ...prediction model.
Design/methodology/approach
Several accelerated shear stress tests under different stress amplitudes and aging temperatures were performed.
Findings
It was found that by aging temperature increasing, the lifetime decreases. Morrow energy model was also found as the best prediction model when the aging temperature is taken into consideration.
Originality value
It is confirmed.
The purpose of this research is to investigate the corrosion resistance of 5052 aluminum alloy to increasing salinity in sea water. Salt spray chamber was used to measure and compare the corrosion ...rate of 5052 aluminum alloy with weight reduction method. The experiment was conducted by varying the three concentrations of NaCl solution to compare the corrosion rate of the metal. The test specimens used were aluminum alloy 5052 with length of 6 cm, width of 4 cm and thickness of 0.7 cm. The tests were carried out for 48 hours, aggressive NaCl solutions with concentrations of 3.5%, 4% and 5% were used as an artificial sea water corrosion medium and the temperature in the test chamber was maintained at 35 °C. Corrosion rate for 3.5% NaCl solution, 4% NaCl solution and 5% NaCl solution were 0.197 mm/year, 0.541 mm/year and 0.558 mm/year, respectively. The higher concentration leads to greater corrosion rate.
•Residual thermal stresses may cause failure modes of proper coatings.•TiN coating of Fe substrate by physical vapor deposition is analyzed numerically.•Thermophysical TiN properties are affecting ...the thermal stresses of the coating.•Influence of TiN coating thicknesses of Fi substrate on the thermal stresses is investigated.•An increase in deposition temperature is linearly increasing the thermal stresses.
The residual stress generated after thin layer TiN coating by Physical Vapor Deposition is reducing the mechanical and tribological properties of TiN. Thermal stresses are one of the residual stress components which can cause failure modes of proper coatings. In this article, a validated computational simulation was developed to investigate the effect of physical and thermal properties on the thermal stresses of the coating, including the deposition temperature, Young's modulus of coating, the thermal expansion coefficient of coating, and the thicknesses of coating and substrate. An analytical method using Stoney & Tsui model was used to verify the simulation result by Abaqus software 6.14–5, and very good agreement was achieved. Results show that the thermal stress distribution is discontinued large difference between high stresses in the coating and low stress in the substrate. Also, increasing the deposition temperature from 100 ºC to 500 ºC increases the thermal stresses from 214 MPa to 1355 MPa linearly. Analysis of the coating thickness in the range of 1–5 µm slightly reduces the thermal stress from 1362 MPa to 1342 MPa, while an increase of the substrate thickness in the range of 1–5 mm increases the thermal stress from 1330 MPa to 1360 MPa. It is also realized that an increase in Young's modulus of TiN from 250 GPa to 600 GPa linearly increases the thermal stress from 567 MPa to 1355 MPa, while an increase of the coefficient of thermal expansion of TiN from 3.92×10−6 °C−1 to 9.40 × 10−6 °C−1 reduces the thermal stress from 3418 MPa to 1355 MPa.
Products by solid-state recycling of aluminum chips in hot extrusion process were controlled by temperature related parameters using preheating temperature 450 °C, 500 °C, and 550 °C for 1 hr, 2 hr, ...and 3 hr preheating time. By using Design of Experiments (DOE), the results found that the preheating temperature is more important to be controlled rather than the preheating time and increasing of temperature led to the high tensile strength. The profile extruded at 550 °C with 3 hr duration had gained the optimum case to get the maximum tensile strength. For the optimum case, heat treatment was carried out using quenching temperature at 530 oC for 2 h and aging process at 175 oC for 4 h. The tensile strength of extrudes specimen was improved significantly compared to those of non-treated specimen.
Noise is considered one of the most critical environmental issues because it endangers the health of living organisms. For this reason, up-to-date knowledge seeks to find the causes of noise in ...various industries and thus prevent it as much as possible. Considering the development of railway lines in underdeveloped countries, identifying and modeling the causes of vibrations and noise of rail transportation is of particular importance. The evaluation of railway performance cannot be imagined without measuring and managing noise. This study tried to model the maximum A-weighted noise pressure level with the information obtained from field measurements by Emotional artificial neural network (EANN) models and compare the results with linear and logarithmic regression models. The results showed the high efficiency of EANN models in noise prediction so that the prediction accuracy of 95.6% was reported. The results also showed that in noise prediction based on the neural network-based model, the independent variables of train speed and distance from the center of the route are essential in predicting.
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