In this study, the effect of multidirectional forging (MDF) was studied on the microstructure and mechanical properties of Ti-modified SiP/ZA22 composite containing 4 and 8 wt. % Si. The forging process was performed at 100 °C by two and five passes. Based on the obtained results, Ti modification refined the coarse primary dendrites, and reduced the size of primary Si (SiP) particle as well as grains. Applying MDF also gradually eliminated the dendritic structure, promoted fine distribution of SiP particles, second phases, and porosities in the microstructure. According to the image analysis results, the average size of SiP particles in as-cast composite reduced from 25 and 30 μm to about 6 and 7 μm, respectively in 5-pass MDFed composites containing 4 and 8 wt. % Si. The mechanical properties results also showed work softening during the MDF where after two-pass MDF the hardness and tensile strength of the base sample reduced by 30 and 25%, while its elongation and toughness improved by 120 and 325%, respectively. In MDFed composites, the presence of SiP particles maintains the hardness and strength. According to the results, in the case of 2-pass MDFed composite containing 4 wt. % Si the hardness and tensile strength reduced by 18 and 2%, respectively, but the elongation and toughness increased by 25 and 175%, respectively.

Achieving the desired mechanical properties in in-situ composites is governed by morphological modification, refinement, and even distribution of reinforcement particles which are formed during their solidification. This study was aimed to investigate the effect of Ti addition and multidirectional forging (MDF), as an industrially practical process, on microstructure and shear mechanical properties of cast ZA22-4Si composite. The obtained results showed that chemical modification of composite through 0.2 wt. % Ti addition converted the coarse primary grains to the well-refined equiaxed grains and reduced the size of primary Si particle (SiP), and porosities and improved their distribution within the matrix. The image analysis results also indicated that the average size of grains and SiP particles reduced from 750 and 25 mm to about 135 and 15 mm, respectively. Applying MDF at 100 ° C at the different passes breaks the primary dendrite network, decreased the average size of SiP particles, and promoted their even distribution within the matrix. According to the image analysis results in 2- and 5-pass MDFed composite the average size of SiP particles reached to about 8 and 6 μm, respectively. The shear punch tests also indicated that the combined effect of MDF and Ti addition reduced the strength whilst improved the ductility of as-cast composite where the yield and tensile shear strength of 5-pass MDFed sample reduced from 135 and 164 MPa to about 92 and 130 MPa, respectively, and its normal displacement value improved from 0.52 to about 0.72.

In this paper, 1.7225 steel subjected to severe plastic deformation by using a multi-directional forging method, and mechanical properties such as ultimate tensile strength, yield strength, hardness and, vibration properties were investigated. The use of SPD ( severe plastic deformation ) for changing the size of metals grain to enhance the mechanical properties of the metals were examined. The 1.7225 steel is used for machine tools with appropriate mechanical properties as a tool holder. First Evaluation of load needed for plastic deformation was conducted by using finite elements computer software. By using the results of the software first guess for applied load and stresses on the die for successful results were known. The results of this study showed that the yield and ultimate tensile strength increased 441Mpa and 540Mpa and hardness increased 18HRC. After 2 passes of severe plastic deformation, mechanical vibrations characteristics result no significance change in damping properties.

Commercial pure (CP) titanium has many applications in biomaterials especially in implants due to its excellent biocompatibility. The major weakness of CP titanium is low strength compared to that of other titanium alloys. One of the methods can be used to increase the strength of CP titanium are severe plastic deformation methods such as multi directional forging (MDF). Therefore, the aim of this research is the improvement of CP titanium strength by grain refinement in MDF process. For this purpose, after one hour annealing at 800°C, the CP titanium was forged by MDF process up to six passes at ambient temperature. Microstructural studies were performed by optical microscope and scanning electron microscope equipped with EBSD. Mechanical properties were also studied by Vickers’ microhardness and tensile tests. The finite element simulation by Abaqus software was also applied to predict the strain distribution during MDF process. The results of microstructural analysis showed that the average grain size decreased significantly after the MDF process and increasing the pass numbers of MDF led to an increase in grain refinement. After six passes of the MDF process, the average grain size decreased from 45 microns to 390 nm. Mechanical properties results showed that the strength and hardness of specimens increased with MDF process and increasing the number of passes. The hardness and strength of six passes MDFed specimen was about 2 times greater than those of annealed specimen. The strain distribution results obtained from the simulation showed good agreement with experimental results of microhardness distribution.

In this study, 1.5vol.% of SiC nanoparticles was added to AZ31 magnesium alloy via a stir-casting method. Next, the as-cast ingots were extruded at 400°C with the ratio of 3.78. After extruding, the materials were subjected to multidirectional forging (MDF) at 320°C for 2, 4, 6, and 8 passes. In order to evaluate the mechanical properties of extruded and MDFed materials, shear punch (SPT) and Vickers microhardness tests were applied. The results of these tests showed that hard ceramic nanoparticles improved the shear strength and hardness of the matrix alloy. The shear yield strength, ultimate shear strength, and hardness of extruded alloy were 86.70 MPa, 119.43 MPa, and 52.55 HV, respectively, while in extruded AZ31/SiCp nanocomposite, these values increased by 9.91%, 5.48%, and 13.99%, respectively. It was also observed that nanocomposites processed with multi-directional forging offer better mechanical properties than non-MDFed materials. The results indicated that after the first two passes, there was a significant improvement in the mechanical properties of the nanocomposites, such that the shear yield strength, ultimate shear strength, and hardness were improved in contrast with the extruded state by 27.12%, 17.95%, and 16.03%, respectively. Mechanical properties during the next passes were periodically reduced and increased. Microstructural observations also showed that the average grain size variations were periodic during the increase of MDF passes. After the second pass, the grains were finer than the extruded state, and their size increased in the next two passes. From 4th to 6th pass, the grain size decreased and the smallest grains were obtained in this case, while in the last two passes, the grains grew slightly. Despite the smaller and homogeneous structure created by the 6th and 8th passes, the best mechanical properties were obtained in the second pass, which means, in addition to the microstructural changes, also modifications in the material texture during the MDF process had an impact on mechanical properties.

In this Study, the necessary force of the isothermal forging process of disc piece of aluminum alloy AA7075 was analyzed and calculated by theoretical methods and finite elements method. In the simulation of the isothermal forging process in Deform software, were selected the temperature of 400 °C, the speed of top mold of 0.1 mm/s and the shear friction coefficient of 0.075 as process parameters. The necessary force of isothermal forging was obtained 80 tons in 6.18 mm Motion Course for disc piece by analyzing the simulation results of finite element method in DEFORM software. The axisymmetric slip line field method was used to estimate the forming force of the isothermal forging of the closed die before of the flash filling, which obtained 23.54 tons. The comparison forming force of isothermal forging of disc piece by theory method with the results obtained from finite element simulation showed that the forming force corresponds very well with the force-displacement diagram is compatible. The geometry of billet, the final top and bottom dies and assembly drawing of isothermal forging process of disc piece of aluminum 7075 dies were calculated by assuming a constant volume in plastic deformation.

The slab method can predict rapidly the rolling force and torque in metal forming processes and a large amount of CPU time can be saved. Up to now, the work hardening effect has not been considered in the slab analysis for forging process of double-layer clad sheet. Evaluation of considering or eliminating the work hardening effect of material behavior in the slab analysis of three layer clad sheet forging process and investigating the subsequent effects on the process outputs are a novel subject considered in this paper. The pressure distribution as well as the forging force are investigated for both conditions. In addition, three layer clad sheet forging process is simulated entirely using ABAQUS/Explicit software. The results have showed that considering the work hardening will result into having larger stresses and forces in the process. Moreover, the results of considering the work hardening have better agreements with those from simulation. Finally, some experiments were performed on forging process of two layer Al/Cu clad sheet to evaluate the bonding quality of sheets. Therefore, forging process can be used for producing multi-layer clad sheets in various industries.

Friction is one of the most effective parameters in the forging process، which its analysis is needed. Efficient lubrication is best way in controlling friction and wear in this process. Because of the low cost of lubrication in comparison with the reductions that it creates in cost، testing the lubricants is important in forging. One of the best ways of testing the lubricant is the ring compression test، which with finite element method، the friction coefficient is calculated. In this research the effect of mixed graphite in water and also the effect of the amount of graphite in the lubricant in the reduction of friction was calculated using the ring test. Effect of the lubricant was easily recognized in the final dimensions of the specimens in result of the reduced friction; this was seen in the changing of sticking friction to sliding friction. Nevertheless، the changes in the amount of graphite in water did not have a great effect on the reduction of the friction coefficient. Furthermore، after viewing differences in the friction coefficients calculated by the means of finite element analysis ABAQUS software and the frictional calibration curves، it was concluded that the sole calibration curves could not be used for hot working conditions.

This Paper presents the welding parameter''s effect (forging pressure¡ welding time) on macrostructure and mechanical properties of friction welding valve steel HNV3 to Nimonic 80A super alloy. For this purpose¡ two rods with 20 mm diameters are prepared and with using different parameters (Increase forging pressure and welding time) by friction welding method are welded together. Tensile Test carried out on samples for investigating the effect of a parameter. It was discovered that when the welding parameters used in connecting HNV3 and Nimonic 80A Superalloy couple through friction welding were selected correctly; strength of the connection would increase compared to the main material.