@article { author = {Safdarian, Rasoul and Torkamany, Mohamad Javad}, title = {A Novel Approach for Formability Prediction of Tailor Welded Blank}, journal = {Iranian Journal of Materials Forming}, volume = {3}, number = {2}, pages = {1-12}, year = {2016}, publisher = {Shiraz University}, issn = {2383-0042}, eissn = {2383-0042}, doi = {10.22099/ijmf.2016.3797}, abstract = {Formability of Tailor Welded Blank (TWB) is an important parameter which limits this kind of blanks usage. A forming criterion for tailor welded blank is presented based on the analytical model in this research. This criterion suggests Limit Strength Ratio (LSR) and Limit Thickness Ratio (LTR) for forming limit of TWB. When thickness ratio or strength ratio in tailor welded blank is greater than LTR or LSR, formability will be limited and necking will happen sooner. The influence of thickness ratio on the formability of TWB has been investigated by experimental tests and Finite Element (FE) simulations, but strength ratio has just been studied by simulation. All the simulation and experiment results indicate that by the increase of thickness ratio and strength ratio, the formability will decrease and weld line movement will increase. The obtained results of the present study indicate that fracture happens in the thinner side of TWB and near to the weld line. Moreover, fracture line is parallel to weld line and the fracture position moves farther than weld line by thickness ratio decreasing. Simulation results have a good agreement with experimental results as well.}, keywords = {Tailor Welded Blank (TWB),Limiting Thickness ratio (LTR),Limiting Strength Ratio (LSR),Weld line movement}, url = {https://ijmf.shirazu.ac.ir/article_3797.html}, eprint = {https://ijmf.shirazu.ac.ir/article_3797_afa8477abd4612500fb7c97c8e46b452.pdf} } @article { author = {Khosravifard, Amir and Hematiyan, M. R.}, title = {Meshless analysis of casting process considering non-Fourier heat transfer}, journal = {Iranian Journal of Materials Forming}, volume = {3}, number = {2}, pages = {13-25}, year = {2016}, publisher = {Shiraz University}, issn = {2383-0042}, eissn = {2383-0042}, doi = {10.22099/ijmf.2016.3798}, abstract = {Casting is considered as a major manufacturing process. Thermal analysis of a solidifying medium is of great importance for appropriate design of casting processes. The conventional governing equation of a solidifying medium is based on the Fourier heat conduction law, which does not account for the phase-lag between the heat flux and the temperature gradient. In this paper, the concept of phase-lag during the phenomenon of solidification is investigated. This concept is considered by utilization of the hyperbolic heat conduction equation, known generally as the Maxwell–Cattaneo relation. In this way, the effect of finite heat wave speed on the thermal behavior of a solidifying medium is studied. In this context, some numerical example problems are analyzed with the meshless radial point interpolation method. The effect of the relaxation time on the thermal behavior of the solidifying medium is investigated. Moreover, the results of Fourier and non-Fourier heat conduction equations are compared. It is observed that based on the specific solidification process and the amount of relaxation time, the results of the Fourier and non-Fourier conduction laws can be quite different. The most prominent effect of the relaxation time is to alter the initiation of the solidification at each point.}, keywords = {Phase-change,non-Fourier heat conduction,meshless radial point interpolation method}, url = {https://ijmf.shirazu.ac.ir/article_3798.html}, eprint = {https://ijmf.shirazu.ac.ir/article_3798_105471d9f888e2222d231c10f9000f58.pdf} } @article { author = {Ansari Basir, Ehsan and Narooei, Keivan}, title = {Simulation of deformation behavior of porous Titanium using Modified Gurson yield function}, journal = {Iranian Journal of Materials Forming}, volume = {3}, number = {2}, pages = {26-38}, year = {2016}, publisher = {Shiraz University}, issn = {2383-0042}, eissn = {2383-0042}, doi = {10.22099/ijmf.2016.3861}, abstract = {In this research the stress-strain curve of porous Titanium, as a common material for biomedical application, was predicted using the mechanical properties of fully solid Titanium experimental data. Modified Gurson model (Gurson-Tvergaard-Needleman (GTN) model) was used to predict the plastic response of porous Titanium in compaction. Different values of GTN parameters were used for different initial porosity. It was recognized that volume constancy assumption during plastic deformation of porous media cannot be satisfied due to both of changes in porosity and hydrostatic stress contribution on yielding. It was found that consideration of porosity variation is necessary during deformation for accurate modeling. Also, porous samples represented the same lateral expansion under less axial displacement relative to fully solid sample regarding the GTN model. The stress distribution of porous samples was different from solid sample considering the GTN model and this was predicted different shear banding. Evolution of porosity during deformation leads to linear like stress response in the plastic deformation regime.}, keywords = {Modified Gurson model (GTN),Porous Titanium,Finite element method,Plastic deformation,Compaction}, url = {https://ijmf.shirazu.ac.ir/article_3861.html}, eprint = {https://ijmf.shirazu.ac.ir/article_3861_69fd0568b9d19964c431268e3bb2a42c.pdf} } @article { author = {Vafaeenezhad, Hossein and Seyedein, S. H. and Aboutalebi, M. .R. and Eivani, A. R.}, title = {Workability study in near-pritectic Sn-5%Sb lead-free solder alloy processed by severe plastic deformation}, journal = {Iranian Journal of Materials Forming}, volume = {3}, number = {2}, pages = {39-51}, year = {2016}, publisher = {Shiraz University}, issn = {2383-0042}, eissn = {2383-0042}, doi = {10.22099/ijmf.2016.3862}, abstract = {Prediction of the deformation characteristics is an important step to understand the workability of alloys during imposing large strains. In this research, severe plastic deformation of Sn-5Sb solder alloy was carried out under different t deformation conditions, including the temperature range of 298, 330, 36, 400 K and die designs. The current study applies an experimentally validated finite element method (FEM) to establish a model for predicting workability in equal channel angular pressing (ECAP). To do this object, two ECAP dies were prepared with channel angle of 90 and the outer corner angle of 30O with and without choked angle in outlet channel. Angularly pressed Sn-5Sb solder alloy were utilized for validating the proposed FEM model. Different parameters such as die angles (angle between the channels and the outer corner angle), pressing temperature and the die outlet channel geometry were studied using FEM simulation. In conclusion, experimentally verified numerical data were successfully used for proficient die design and process determination in the ECAP of tin alloy. The obtained results of hybrid FEM model were in acceptable conformity with experimental measurements.}, keywords = {Solder alloy,Finite element method,equal channel angular pressing}, url = {https://ijmf.shirazu.ac.ir/article_3862.html}, eprint = {https://ijmf.shirazu.ac.ir/article_3862_0d6483b512f5cf1893e0dabd4f471a08.pdf} } @article { author = {Tolouei, Ehsan and Toroghinejad, Mohammad Reza and Ashrafizadeh, Fakhreddin}, title = {An investigation on the bond strength of aluminum strips in presence of brass mesh after cold roll bonding}, journal = {Iranian Journal of Materials Forming}, volume = {3}, number = {2}, pages = {52-63}, year = {2016}, publisher = {Shiraz University}, issn = {2383-0042}, eissn = {2383-0042}, doi = {10.22099/ijmf.2016.3863}, abstract = {In the present study, the presence of brass mesh on the bond strength of aluminum (AA1050) strips in the cold roll bonding process was investigated. The influence of various process parameters including reduction in thickness, pre-rolling annealing, initial thickness of the strips, and post-rolling annealing was also considered. After cold roll bonding process, peeling test was carried out and peeled surfaces were examined by optical and scanning electron microscopes (SEM). Energy dispersive spectroscopy (EDS) analysis also, revealed that there was neither diffusion zone, nor formation of intermetallic at the interface of aluminum and brass wires after annealing at 643 K. It was found out that, by increasing the amount of reduction and initial thickness, the bond strength of the layers was increased. Furthermore, pre-rolling and post-rolling annealing treatments at 643 K increased the bond strength, and the effect of post-rolling annealing on the bond strength was more than pre-rolling annealing.}, keywords = {bond strength,Cold roll bonding,Peeling test,Composite}, url = {https://ijmf.shirazu.ac.ir/article_3863.html}, eprint = {https://ijmf.shirazu.ac.ir/article_3863_764ab4ee165e51ea777c1645af9e13b8.pdf} } @article { author = {Farshidi, Mohammad Hassan}, title = {New geometry for TCP: severe plastic deformation of tubes}, journal = {Iranian Journal of Materials Forming}, volume = {3}, number = {2}, pages = {64-78}, year = {2016}, publisher = {Shiraz University}, issn = {2383-0042}, eissn = {2383-0042}, doi = {10.22099/ijmf.2016.3871}, abstract = {Since tubes are widely used for different industrial applications, processing of tubes by the Severe Plastic Deformation (SPD) method has been the target of different attempts. Among these attempts, development of SPD processes for tubes based on Equal Channel Angular Pressing (ECAP) has been more successful. As an illustration, Tube Channel Pressing (TCP) has been presented as an attractive SPD process since a relatively homogenous strain can be imposed on different sizes of tubes by this process. However, since die/mandrel geometry has a remarkable effect on the deformation behavior of tube in this process, more efforts must be focused on the optimization of the geometry of this process. This work is aimed to examine a new die geometry for TCP in order to reduce the strain heterogeneity and rupture risk of tube through the process. For this purpose, the effects of different geometrical parameters on the deformation behavior of tube during the process are studied using FEM simulations. In these simulations, the rupture risk of tube is considered using a damage criterion and then, results of simulations are compared with experiments. Results show that the new geometry of TCP imposes more intense strain, causes less strain heterogeneity and results in less risk of rupture of tube during the process. In addition, comparison of simulations and experiments shows that the applied simulation method can predict the rupture of tube during TCP. Besides this, different geometrical parameters of the new geometry of TCP are optimized by simulations considering dimensions of tube.}, keywords = {severe plastic deformation,Tube,FEM simulation,Strain distribution,Rupture prediction}, url = {https://ijmf.shirazu.ac.ir/article_3871.html}, eprint = {https://ijmf.shirazu.ac.ir/article_3871_76b42da6f65d4406903763f87d826305.pdf} }