Abstract: Design equations based on die expansion are derived for selecting punch and
counterpunch dimensions in completely closed die forging. The method imposes lower limits
on the punch (counterpunch) – container radial clearance and forging height tolerance that
may be specified.
Abstract: The present paper studies the process of electro discharge machining, estimating the
relative importance of main influence factors.
The first step is to evaluate the possibilities of a design of experiments based on an orthogonal
array, an appropriated method to systems with multiple factors changing in numerous levels
After of the realization of the experiences the theory of grey systems is used to know which
combination of factors optimize all of the variables.
Finally the analysis of the variance is applied to investigate which of the factors significantly
affects the global answer of the system.
Abstract: The Finite Element Method (FEM) has become an indispensable tool in metal forming
analysis [1,2]. Contrary to the traditional methods, FEM allows to analyze more realistic situations, either
geometric and tensional. On the other hand, the drawing process is one of the most ancient metal forming
operations and, nowadays, this process is widely used in industrial field. However, the influence of the
main parameters in the mechanics and efficiency of the process has been scarcely studied. Drawing
processes have been analysed by FEM, assuming plane strain and axisymmetrical conditions in order to
check the possibility of extrapolating results from one case to another. Besides, this numerical method is
compared with analytical and experimental methods. Also, FEM is used for studying the influence of
several technological parameters on variables such as the drawing force or the die pressure, and for
obtaining results of stresses and strains in certain regions of the model.
Abstract: In this work, the strain field attained by using a severe plastic deformation (SPD) process
called equal channel angular extrusion (ECAE) is studied by the finite element method (FEM). The
three-dimensional model with circular section includes shear friction between the part and the die,
the material strain hardening behaviour and a rigid-deformable contact between the billet and the
die. In the ECAE process the part is extruded through two channels with similar diameter that
intersect at an angle. When the extrusion process has been performed, the processed material
remains it cross section, so there is not any geometric limitation to achieve the desired plastic strain.
There are different ways of processing the material by using the ECAE process; those ways of
processing are called routes. In this work two passages of route C have been simulated. Using route
C means that the billet has been rotated 180º between each passage. Deformations imparted to the
processed material have been calculated and a comparison with experimental results has been
Abstract: The main objective of this work is the analysis of hydroforming for the manufacture of
joint bellows of AISI 316 steel for different values of diameter. The initial thickness of the metallic
tube is of 1 mm and diameters between 500 and 1200 mm are considered. The Finite Element
Method is applied to study the tensile stress and thickness reduction at the wave peak of the final
part. The numerical results are compared to the recommendations given by the EJMA standard.
More critical values of wave thickness and tensile stress are predicted by simulation.
Abstract: This study starts from a firm’s needs to improve manufacturing costs and times in an
external turning operation with the material according to the standard AISI 630 (martensitic
stainless steel, hardened by precipitation), with a hardness of 355 HB. It has been developed a basic
factorial design of experiments with two factors (cutting speed and feed per revolution), with
constant depth of cut and two levels, with three central points. This experiment has resulted in the
obtaining of the machined meters from a tool life criterion, which has limited basically the tool
flank wear, VB = 0,2 mm. The balance between the tool wear, maximum machining length and the
minimum machining time has been considered from the analysis of the results.
Abstract: The paper evaluates the feasibility of monitoring cutting forces for in-process prediction
of the workpiece surface roughness, using regression based models (RG) and artificial neural
network (ANN) techniques. The three orthogonal cutting force components (Fx, Fy, Fz) and the
machined length L have been chosen as input variables. In the experimental test, AISI-1045 steel
material was turned using a TiN coated carbide tool and employing a range of machining conditions
(cutting speed: v=150, 200, 250 m/min; feed rate: f=0.15, 0.20, 0.25 mm/rev; depth-of-cut: d=1, 2, 3
mm). The results provided a wide range of measured cutting force and surface roughness values (Ra
and Rq), which were used for adjustment and validation of the prediction models. Two prediction
models were developed and subsequently the model accuracy was assessed by comparing the
surface roughness predicted by the models with that measured by a 2D profilometer. The results
highlighted the reasonably good fit given by both models, with the ANN based model providing best
accuracy for surface roughness prediction. The prediction of the output surface roughness in an
automated turning process was established and was found to be feasible by the monitoring of
Abstract: A laser polishing method applied on metallic surfaces is presented in this work. One of
the most important applications of this technique is the small-medium injection mould polishing
manufactured by rapid manufacturing processes (RM) such as selective laser sintering. The
polishing method has been applied to different surfaces including a laser-sintered part. Topography
and roughness parameters measurements show that laser polishing can achieve surface
improvements up to three times in mean roughness parameter with no macro-geometric deviations.
Abstract: The aim of the paper is to present the influence of a new multifunctional material, a
master alloy named Al-Sr-Ti-B, in aluminum foundry alloys. The Al-Sr-Ti-B master alloy
represents a new combination of two master alloys, already known in aluminum industry, AlTiB
and AlSr, used in treatment of aluminum alloys for grain refining and modification. As Strobloy,
our master alloy contain fast dissolving SrAl4 particles and also nucleating particles as TiB2 and
(Al,Ti)B2 which are important first in modification and second in grain refining of aluminum alloys.
The paper presents optic and electron microscopy studies realized on AlSi7Mg alloy treated with
this new multifunctional material
Abstract: In this paper, a mathematical model has been developed for the cutting tool stresses in
machining of nickel-based super alloy Inconel 718 used in aircraft and spacecraft industries, nuclear
power systems and steam generators etc. necessitating oxidation and corrosion resistance, high
temperature and strength. The cutting forces were measured by a series of experimental
measurements and stress distributions on the cutting tool were analyzed by means of the finite
element method using Ansys software. The mathematical modeling process of the compressive
stresses in x, y and z directions was carried out with multiple regression analysis regarding to Ansys
stress results depending on the cutting forces and the chip–tool contact area. It is found that model
results had good agreement with the Ansys stress results.