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Go to Editorial ManagerIn this study the friction stir lap welding was carried out by a new technique (diffusion bonding phenomenon) between (AA1100 and low carbon steel C10 sheets of 3mm and 1mm thickness respectively. These alloys have difference ranges in melting temperature and other physical properties. Different parameters were used: tool rotation speeds (630, 1250) rpm, travel speeds (80, 32) mm/min. and pin length (2.8,3) mm using cylindrical threaded pin. Many tests and inspections were performed such as tensile shear test and X-Ray diffraction tests. Microhardness and microstructure observations were conducted by using optical and SEM. The above tests were used to evaluate the weld quality and joint efficiency under different welding parameters. Best result for FSLW by diffusion phenomenon appear in (low carbon steelC10 / AA1100-H112) joint at 1250rpm in 32 mm/min. with 2.8mm pin length and the maximum tensile shear strength was (3.9)KN.It was found that the highest micro hardness was (138HV) at the interface between the low carbon steel and AA1100.
An important challenge confronted when using blanking to machine sheet metal is the treatment of the shearing force in demand for great strength and heavy stock. One of the methods used to decrease the force wanted is the increase of a punch shear angle. In this work, experiments were conducted to study the effect of shear angle for blank has a diameter (50 mm) on shear force of a low carbon steel sheet (AISI 1008). Low carbon steel is a very common material used in fabrication of sheet metal components, with thickness of (0.5 mm). Tools used in the blanking tests were one traditional flat end punch and four different bevel sheared rooftop punches, which rooftop punches were compared to. and it (0°, 5°, 10°, 15°, 20°) a punches diameter (49.95 mm) by clearance (0.025mm) for each side , with a blanking speed (500mm/min). A special blanking die set is designed and manufactured and was a blank cut by a hydraulic press whose capacity (20 ton). The results showed that the blanking forces of (AISI 1008) low carbon steel metal could be decreased radically with best bevel punch geometry. Using (10°) shear angle at the punch end, the cutting forces decreased up to (90%) compared to the ones of the traditional flat end tool
Desired mechanical properties like microstructure, micro hardness and wear resistance are the key parameters for which low carbon steel (AISI 1006) are widely selected. Surface heat treatment applied to improve these properties; traditionally surface heat treatments like induction hardening, in recent time’s laser surface hardening. In this work, thermochemical treatment (liquid nitriding) by using mixture from 61% NaCN, 15% K2CO3 and 24% KCL and followed by Nd:YAG laser surface treatment was done . The laser parameter were energy (0.89, 2, 4 and 9) J, spot diameter (0.790 ,0.33, 0.283 and 0.224) mm, pulses duration (1, 2.33, 4.47 and 9.87) ms with fix wavelength 1604nm. Laser surface treatment cycle was melting the layer surface, holding and rapid cooling in air medium. Optical microscopy (OM) and scanning electron microscope (SEM) has been used to study the microstructures and cross-sectional of molted and heat affected zones respectively. The wear test was done to measure the wear rate by using pin -on-disk principles were satisfied. The result shown that increasing in laser energy effects to increase in the area of melted and heat affected zones of nitriding steel. Also increasing in laser energy led to increase micro hardness about 61%, while wear rate decrease about 40 % and increased depth of molted zone.
The Electrodeposition process has been used to prepare Nickel-Tungsten alloys on low carbon steel substrate by using ammonical citrate bath. The influence of deposition condition by variation of current density (0.04-0.2 A/cm2) and solution temperature (60-70 °C), on the microstructure was studied. The optical microscope and the scanning electron microscopy (SEM) were used to study the morphology of the deposit while the energy dispersive spectroscopy (EDS) was used to approximate the composition, in addition to X-Ray diffraction examination. The results show that the current efficiency has the major influence on the tungsten content in the alloys due to the formation of ternary complex which reflected into the properties of the deposit._x000D_ Keywords:
Welding residual stress has influences on fatigue, fracture, and corrosion. It is therefore important to explore the welding factors effect on the residual stresses. In this work, four welding factors (current, arc voltage, welding travel speed and included angle) were used to weld low carbon steel (ASTM A516 Grade 60).The experiments included welding of (60) pieces with dimensions of (300 x 150) mm and 10 mm thickness that were conducted based on the design matrix founded by using design of experiment (DOE) software (DESIGN EXPERT 10) with response surface methodology (RSM) technique. The X-Ray diffraction (XRD) method was used to measure the residual stress, which was then modeled and optimized in terms of the welding factors using (RSM) technique. The data showed that the welding travel speed and arc voltage have a significant influence on the residual stress. It was found that the optimum solution for minimum residual stress was at 450 Amp welding current, 34 volt arc voltage, 38 cpm welding speed, and 60? included angle. Where, the optimum value of residual stress was (-88.4 MPa). Finally, the predicted and experimental results of residual stress were in agreement with a maximum error of 1.8%.
In this research, experimental and analytical deep drawing of the several-stages design mold is produce hexagonal cup and also proved the influence of the thickness of the sheet on the allocation of strain and laminating in curvature of the cup area for all stages of the drawing. Three stages deep drawing mold was designed and constructed to carry out the experimental work required to produce a hexagonal cup of (28.25 mm by 24.5 mm) , (60 mm) high drawn from a circular flat sheet (80 mm diameter), made from low carbon steel (1006–AISI). Analysis program (ANSYS11.0) to perform the finite element method to accomplish the analytical side of the search. Three types of thickness sheet (tt°= 0.5, 0.7,1 mm) with constant radius of curvature of punch equal to (RRpp =4) mm, radius of curvature of die equal to (RRdd=8 mm)and radius of curvature of wall of die (RRcc= 4 mm) were used. From the experimental and analytical results of the three stages of drawing, it has been found that drawing load less than the more advanced stages of drawing operation on the wall of cup, maximum laminating take place at curvature of the cup area with sheet thickness equal to (tt°=0.5 mm) and maximum thickeningtake place at the at throat cup with sheet thickness equal to (tt°=1 mm), the maximum values of strains (radial, hoop, thickness andeffective)take place at throat cup with sheet thickness equal to (tt°=1 mm).
This work describes seam welding process using dissimilar ferrous metals by pulsed Nd:YAG. The main objective of this work is to achieve the best welding conditions. This imposes careful selection for the welding parameters and inevitably the well design of experiment (DOE). Sheets of ASTM A240/316L stainless steel to ASTM A570/Gr30 carbon steel all of 0.5 mm in thickness were lap welded. Different pulse energies or the related peak power, pulse duration, pulse repetition rate, and welding speeds were used. Moreover, different welding speeds were controlled by the employed manipulator. The laser beam spot diameter and the standoff distance were fixed. Experimental results are supported by the computational 2D and 3D models. In this article response surface methodology (RSM) was applied to design the experiment and obtain the best parameters through a set of mathematical models that define the weld characteristics. The results show that the best joint in term of joint strength is obtained at 31.9 J pulse energy (related to 5.5 kW peak power and 5.8 ms pulse duration), power density of 1.43×106 W/cm2, 1.5 Hz pulse repetition rate, and 0.5 mm/s welding speed.