Abstract: In this paper global welding buckling distortion of a thin wall aluminum T joint is
investigated. A thermo-elastoplastic model is employed to determine longitudinal residual stresses;
analysis of thermal model and elastic-viscoplastic (Anand) model are decoupled. Molten puddle
motion (speed of welding) is modeled by using birth and death element method and time dependent
model. Three dimensional nonlinear-transient heat flow analysis has been used to obtain
temperature distribution, and then by applying thermal results and using three dimensional Anand
elastic-viscoplastic model, stress and deformation distributions are obtained. By applying residual
stresses on a structural model and using eigenvalue methods, global buckling instability of the
welded structure is determined. Some experiments are done for validating the numerical results.
Abstract: Aluminum foams offer an attractive combination of attributes as engineering materials,
such as low density, high rigidity, high energy absorption, and fire resistance. To date, however,
metallic foams have achieved only a fraction of the market acceptance enjoyed by polymeric
foams, owing largely to size limitations, poor uniformity and, above all, high unit costs. Methods
utilizing casting (non-powder) metallurgy, while seemingly offering the potential of economies of
scale, often suffer quality issues such as large cell sizes, poor uniformity and insufficient structural
integrity. Many of these problems are associated with the rheology of the molten metal itself.
While prior efforts to modify melt rheology through extrinsic additions of ceramic particles have
been shown to be effective, the costly materials and processing paths used to create such
suspensions have limited the economic attractiveness of such products. In this paper, aluminum
foams produced through an alternative processing method will be described. The physical and
mechanical properties in these fine (< 1 mm) celled aluminum foams will be related to their cellular
structure and the properties of the aluminum alloy matrix from which they are produced.
Abstract: Use of aluminium in modern cars has increased during the past 50 years due to the good
properties of the metal and the need for light weighting cars. The permanent rise in energy costs
and need for reduction of emissions world wide make aluminium more and more attractive for
automotive use. Nevertheless, additional costs for light weighting must remain affordable –
materials scientists and process engineers are challenged to meet these requirements.
Abstract: The web-based e-learning tool “AluMATTER” is presented which can be accessed under the
address “http://aluminium.matter.org.uk” and offers a new interactive course for students, engineers
or technicians to learn all about Aluminium science and technologies. The e-learning program
fulfils all distant learning requirements and intends to supplement regular teaching courses. It
allows users to access the material in a context relevant to their own requirements and background.
Abstract: An innovative process for synthesising bulk materials using particles has been
developed. The process is termed back pressure equal channel angular consolidation (BP-ECAC).
Aluminium based materials were successfully consolidated into bulk materials using particles from
nano to micro scales. BP-ECAC allowed the particles to be used directly without pre-compacting
and casing and the processing temperatures to be significantly lower than those used in
conventional sintering. Fully dense bulk samples were obtained instantaneously as the particles
were forced to pass the shearing zone under pressure. Nanostructured materials were obtained from
the nanometre-sized Al particles. Significant strengthening of the consolidated materials were
observed. The new process is promising in producing porosity free, large volume materials with
special compositions and structures.
Abstract: Aluminium foam sandwich panels (AFS) made of a low-density aluminium alloy
AlSi6Cu6 foam core and two dense 6082 alloy face sheets were fabricated, after which the panels
were subjected to two different heat treatments. First, the AFS panels were aged to increase their
strength without further solution heat treatment and fast quenching, a process which resembles a T5
treatment. Second, to define a reference point the face sheets of AFS samples were cut off the foam
and subjected to a full T6 treatment. Hardness profiles were measured across the thickness of the
face sheets after the two different treatments and the microstructure was investigated. The main
conclusion is that mechanical performance of AFS panels can be considerably increased by heat
treatment without full solution heat treatment (T5), but without reaching the level of a full T6
treatment. The potential use of an easy to apply T5 treatment is an important cost reducing factor.
Abstract: Accumulative Roll Bonding (ARB) is a technique of grain refinement by severe plastic
deformation, which involves multiple repetitions of surface treatment, stacking, rolling, and cutting.
The rolling with 50% reduction in thickness bonds the sheets. After several cycles, ultrafine-grained
(UFG) materials are produced. Since ARB enables the production of large amounts of UFG materials,
its adoption into industrial practice is favoured. ARB has been successfully used for preparation of
UFG sheets from different ingot cast aluminium alloys. Twin-roll casting (TRC) is a cost and energy
effective method for manufacturing aluminium sheets. Fine particles and small grain size are intrinsic
for TRC sheets making them good starting materials for ARB. The paper presents the results of
a research aimed at investigating the feasibility of ARB processing of three TRC alloys, AA8006,
AA8011 and AA5754, at ambient temperature. The microstructure and properties of the ARB were
investigated by means of light and transmission electron microscopy and hardness measurements.
AA8006 specimens were ARB processed without any problems. Sound sheets of AA8011 alloy were
also obtained even after 8 cycles of ARB. The AA5754 alloy suffered from severe edge and notch
cracking since the first cycle. The work hardening of AA8006 alloy saturated after the 3rd cycle,
whereas the hardness of AA5754 alloy increased steadily up to the 5th cycle. Monotonous increase in
strength up to 280 MPa was observed in the ARB processed AA8011 alloy.
Abstract: Alcoa has made a fundamental shift in its aerospace R&D program, broadening its
scientific and engineering portfolio by creating an integrated, strategic, long-term initiative. The
ultimate goal is to help re-define the future performance, cost and value of the metallic and hybrid
aerostructures that the company feels will be required to meet the mission requirements of
tomorrow’s aircraft. Having intensely studied various structural options, Alcoa believes Hybrid
Structural Assembly optimized with a combination of Advanced Aluminum and Hybrid
Components offer the best opportunities to maximize structural performance. Not only do the new
alloys, notably 3rd Generation Al-Li alloys and high strength and high toughness 7xxx alloys
provide structural performance enhancements, they also offer dramatic improvements in corrosion
resistance. In this paper, several advanced alloys and structural concepts targeted for next
generation wing and fuselage applications and large scale test article results supporting Alcoa’s
optimism for Advanced Metallic and Hybrid Structures are reviewed.
Abstract: Recycling aluminum alloys has been shown to provide major economic benefits, as a
result it is appropriate for the aluminum industry and the United States as a whole to identify,
develop, and implement all technologies that will optimize the benefits of recycling. This paper
will focus primarily alloy design for optimizing the reuse of recycled metal; this is both the most
forward looking as we move toward a more recycling friendly world and the most overlooked for
its potential in maximizing the recycle loop. Some specific approaches to alloy design for
recycling are put forth, and some specific compositions for evaluation are proposed. Options for
moving forward to further capitalize of the advantages of aluminum recycling are also addressed.
Abstract: Aluminum alloys with high Mg2Si-content (>10 %) offer the possibility of a significant decrease
in density and an increase in stiffness at the same time. But these alloys can hardly be produced in
casting processes, due to an oxidation and a generation of pores by hydrogen solubility of the melt.
Furthermore, the usual solidification rate is not sufficient for a fine microstructure morphology. A
fine distribution of Mg2Si is possible by spray forming, where a coarsening of the particles can be
avoided due to a higher solidification rate. Different aluminum alloys with high Mg2Si-content
(>10 %) have successfully been produced by spray forming, extrusion and age hardening.
Mg-excess as well as Si-excess has been investigated. An additional alloying with copper leads to a
further increase in strength by the precipitation sequence of Al2Cu. The new light-weight aluminum
alloys have been investigated regarding age hardening, physical and mechanical properties.
Densities of 2.5-2.6 g/cm3 and Young´s modulus of approx. 80,000 MPa have been found.
Microstructures were dense, homogeneous and of fine morphology. The yield strength of these
alloys reached values of approx. 400 MPa after artificial aging, whereby only a slight decrease for
the hot yield strength was observed up to a temperature of 200 °C. Applications of the new
light-weight aluminum alloys can be expected where a reduced density together with a high hot
yield strength would lead to a more compact design in high temperature environments, e.g. in