An experimental investigation of fabricated parts by laser melting of Fe-Cu powder mixture, a type of rapid prototyping devices
Seyed Ali
Fatemi
دانش آموخته / دانشگاه خواجه نصیرالدین طوسی
author
Jamal
Zamani Ashany
full Professor/ KNTU
author
text
article
2018
per
One of the main goals of researchers in the laser sintering process of metal powders is optimization of process parameters in order to reach the properties of manufactured parts to the raw material properties. In order to produce fully dense multi-layer parts, it is necessary to optimize the process parameters of a mono-layer part. In the present study, experiments have performed on a powder bed with the thickness of 5mm. The fabricated parts have been produced by a single laser scanning of the powder bed. By moving the laser beam on the powder bed, circular pieces with a diameter of 20 mm have been produced. Based on preliminary experiments and according to the input parameters, a function has defined for energy density. Therefore, output parameters have investigated based on weight percent of Cu and energy density. Results show that there is a saddle point in the diagram of the effect of energy density and the weight percent of Cu on output parameters. This point shows the transmission of sintering to complete melting. Optimal condition of manufacturing parts by rapid prototyping is the condition which strength, surface finish and dimensional accuracy are at the highest possible level while shrinkage, balling and thermal stresses are at the lowest possible level. The results show that the best condition is while the energy density sets between 120-140 W/m2 and the weight percent of Cu sets between 18-22 %.
Iranian Journal of Manufacturing Engineering
انجمن مهندسی ساخت و تولید ایران
2476-504X
5
v.
1
no.
2018
1
12
https://www.iranjme.ir/article_65948_33b8f37fea2454b431d4f1f0238ac2ad.pdf
Optimization of friction stir spot welding process parameters to achieve maximum failure load
Amir Hossein
Sakhaie
M.S Student of Science and Research University, Tehran
author
mohammad
kazemi nasrabadi
assistant professor
Shahid Sattari University of Aerospace Engineering
author
Abdolhossein
Jalali Aghchai
Department of Mechanical Engineering, Khaje Nasir Toosi University of Technology, Tehran, Iran
author
Abozar
Barimani Varandi
Department of Mechanical Engineering, Khaje Nasir Toosi University of Technology, Tehran, Iran
author
text
article
2018
per
Friction stir spot welding (FSSW) process is one of the friction stir welding (FSW) processes which is used for spot joining of thin sheets with different materials without melting of base metals. Box-Behnken design of response surface methodology (RSM) has been used for modelling and optimizing of parameters in different processes. The aim of this study was investigation of the effect of backplate material on the maximum failure load and failure mode in FSSW of AA7075-T6 sheets by using Box-behnken design. Three continuous parameters including rotational speed, plunge depth and plunge speed in three levels and one discrete parameter (backplate material) in two levels were considered. AA7178 and Ti6Al4V were used as backplate sheets. Continuous parameters limits were defined according to experimental tests and previous studies. The results of experimental tests were predicted by second order polynomial. According to statistical results, plunge depth, backplate material, plunge speed and rotational speed affected on the failure load respectively. Shear failure, tensile/shear failure and tensile failure mode were observed after tensile test. Maximum failure load was obtained in tensile failure mode.
Iranian Journal of Manufacturing Engineering
انجمن مهندسی ساخت و تولید ایران
2476-504X
5
v.
1
no.
2018
13
27
https://www.iranjme.ir/article_65945_32f39557416ba65ea0d0696318c7bfa2.pdf
Numerical and experimental study of the edge wrinkling defect of cold roll forming of wide profiles
Hossein
Mohammadi Najafabadi
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Islamic Republic of Iran
author
Hasan
Moslemi Naeini
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Islamic Republic of Iran
author
Rasoul
Safdarian
Department of Mechanical Engineering, Behbahan Khatam Alanbia University of Technology, Behbahan, Khoozestan, Islamic Republic of Iran
author
Davood
Akbari
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Islamic Republic of Iran
author
Mohammad Mehdi
Kasaei
Faculty of Industrial and Mechanical Engineering, Islamic Azad University of Qazvin, Qazvin, Iran.
author
Behnam
Abbaszadeh
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Islamic Republic of Iran
author
text
article
2018
per
The Cold roll forming is a complex forming process which quality of its products is highly dependent on the process parameters. The edge wrinkling defect is one of the common defects in the cold roll forming process of wide profiles. Edge wrinkling leads to several problems such as decrease in dimensional quality, wearing of forming rolls due to contact with the buckled edge and non-uniform distribution of forming forces through the production line. In order to investigate the edge wrinkling defect in this study, the finite element simulation and experimental tests were used. At first, for validation of simulation results, one model in exact in accordance with experimental set up and with one holding station and one forming station to produce one trapezoidal profile was created. Then by simulating this process in Abaqus software and comparing the longitudinal strain in simulation and experimental results, the numerical model was validated. After verifying the numerical model, it was used for simulating a similar profile with two channels in transversal direction and in three forming stations and then the effect of sheet material (yield stress and work hardening exponent), strip thickness and distance between the roll stands are investigated on the edge wrinkling defect of products. Results of this study show that wrinkling increases with the yield stress increase, but decreases with increase in work hardening exponent, strip thickness and distance between the roll stands.
Iranian Journal of Manufacturing Engineering
انجمن مهندسی ساخت و تولید ایران
2476-504X
5
v.
1
no.
2018
28
36
https://www.iranjme.ir/article_65947_af2696a677ea66d3e7bf42b2d3b61401.pdf
Experimental evaluation of deflection and angular distortion of st37 steel plates after induction line heating
Seyed Jalal
Hemmati
Department of mechanical engineering, facualty of engineering, University of Hormozgan
author
Hamed
Abbas Negad
Department of mechanical engineering, faculty of engineering, university of Hormozgan
author
text
article
2018
per
One of the methods for shaping double-curved metallic plates is the line heating process. In this process, they are gradually shaped by heating the plates in the direction of predetermined lines. In the past, mainly gas torches have been used as heating sources. Since the heat flux of the source should be controlled for accurate control of plate deformation during the process and this is not easy with the torch, one of the suitable alternatives is the induction coil as a heating source. In this research, an experimental evaluation of the linear heating induction process of steel plates has been dealt with and studied. Considering the cost of the experimental tests, they were designed by Taguchi method after selecting the effective variables. Thickness of the plate, intensity of the current passed through the coil and velocity of the coil were the studied variables. Deflection and angular distortion of the plate are also considered as the process outputs. Among these variables, thickness of the plate has the greatest impact on the deflection and angular distortion of the plate. Intensity of the current is important in the second order. In the intended range for coil velocity, no significant changes were made in their amount while confirming the impact of this variable on process outputs.
Iranian Journal of Manufacturing Engineering
انجمن مهندسی ساخت و تولید ایران
2476-504X
5
v.
1
no.
2018
37
44
https://www.iranjme.ir/article_65943_2789bf198108495bf916051888c13ed2.pdf
Experimental investigation of flexural behavior of basalt fibers/epoxy-aluminum laminate composites containing nanoclay particles
Farid
Bahari-Sambran
Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran
author
رضا
اسلامی فارسانی
دانشیار دانشگاه خواجه نصیر
author
Hossein
Ebrahimnezhad-Khaljiri
Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran
author
text
article
2018
per
In this study, the effect of different weight percent of modified/unmodified nanoclay particles on the flexural properties of fiber metal laminates (FMLs) made of basalt fibers/epoxy-2024-T3 aluminum sheets was investigated. As a first step, the surface of nanoclay was modified by silane coupling agent which the creation of functional groups on the surface of nanoclay particles was confirmed by Fourier transform infrared (FT-IR) analyses. The modified nanoclay with different weight percent of 0, 1, 3 and 5 was added into the epoxy and then for better distribution and dispersion of nanoparticles in the matrix, the mechanical and ultra-sonication machines were used. Also, for better interaction and adherence between matrix and aluminum sheets, the mechanical and chemical treatment were conducted. Then the mixture of epoxy and nanoclay with woven basalt fibers and aluminum sheets were used to fabricate FMLs. To survey the effect of nanoparticles on mechanical properties, the 3-point bending test was used. The results show that the maximum effect of adding nanoclay on flexural strength and absorbed energy was in 3 wt.% of modified nanoclay, these properties of FMLs, conaining 3 wt.% unmodified nanoclay was weakend in compareson similar specimen, containing modified nanoclay. Furthermore, the flexural modulus was increased by increasing the weight percent of nanoparticles. Also, to investigate the fracture mechanism of polymeric part, the field emission scanning electron microscope (FESEM) was used. The microscopic images were revealed that adding nanoclay are caused improvement of interaction between matrix and basalt fibers, consequently, are caused improving the flexural properties.
Iranian Journal of Manufacturing Engineering
انجمن مهندسی ساخت و تولید ایران
2476-504X
5
v.
1
no.
2018
45
54
https://www.iranjme.ir/article_65946_698469ecde2ba52ade5b6b5dbde48ca0.pdf
Development & Application of Modulated IR Thermography in Non-destructive Evaluation of Composite Materials by an edge detection filter and a morphological attribute profile
karim
jamali
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
author
داود
اکبری
مهندسی ساخت و تولید/دانشکده مهندسی مکانیک/دانشگاه تربیت مدرس
author
mohammad
golzar
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
author
reza
Naeimi Marandi
Department of Electrical Engineering, Tarbiat Modares University, Tehran, Iran
author
text
article
2018
per
In this paper, development of modulated IR thermography non-destructive test has been addressed to detect and evaluate artificial subsurface defects in composite materials by an edge detection filter and a morphological attribute profile. At modulated IR thermography, In order to stimulate the test specimen, the heat flux is applied periodically over the surface of the specimen and the thermal response is decomposed by the Fourier transform method to extract its amplitude and phase images. The non-uniform backgrounds in the obtained images often reduce detection ability. In order to improve the evaluation of this method, an edge detection filter and a morphological attribute profile were applied to the images. Finite element analyses were applied for different frequencies on the model that were simulated with common controlled defects in composite materials. The results of image processing were used in order to locate the defects and it was observed that this method increases the defect detection ability and decreases the possibility of losing the defects in these frequencies.
Iranian Journal of Manufacturing Engineering
انجمن مهندسی ساخت و تولید ایران
2476-504X
5
v.
1
no.
2018
55
62
https://www.iranjme.ir/article_65944_1a357df46602e16bc0314d7057f48d19.pdf