Oct
11
2007
Light alloys
Effects of pouring temperature and squeeze pressure on the properties of Al-8%Si alloy squeeze cast components
A. Raji* & R. H. Khan**
Federal University of Technology, Nigeria
67th World Foundry Congress
This work was conducted to determine the optimum squeeze parameters
for producing squeeze castings from the Al alloy and compare the
properties of the squeeze castings with those of chill castings. Al alloy
Squeeze castings were produced using squeeze pressures of 25-150MPa
at steps of 25MPa with the alloy poured at 650oC, 700oC and 750oC for
each of the indicated pressure into a die preheated to about 250oC.
Squeeze time was maintained ...
Oct
11
2007
Light alloys
The effects of HIP on bifilms in aluminum castings
J T Staley *, M Tiryakioğlu **, J Campbell ***
*Chicago Laboratory, USA, ** Robert Morris University, USA, *** The University of Birmingham, UK
67th World Foundry Congress
Many aluminum castings contain bifilms, which are cracks that lower the
mechanical properties and reliability of castings. The current commercial
hot isostatic pressing (HIP) process has proven successful in closing
porosity but its success in healing bifilms is questionable. This research
investigates the effects of different HIP conditions on the reliability of
aluminum castings affected by bifilms. Non-HIPed, typical HIPed, and
experi...
Oct
11
2007
Light alloys
Mould filling in the lost foam casting of Al alloys
M. J. Ainsworth1 and W. D. Griffiths2
1Gemco Cast Metal Technology, The Netherlands. 2 School of Engineering, University of Birmingham, UK
67th World Foundry Congress
In the Lost Foam casting process the filling of vertically oriented plates
was viewed using a real-time X-ray technique to examine the interaction of
the cast Al with the polystyrene foam pattern. The plates were cast by
means of a counter-gravity technique and bottom-gated running system.
Real-time X-ray images showed that the advancing metal front was
associated with the development of finger-like protrusions as mould filling
velocity ...
Oct
03
2007
Light alloys
Mechanical properties and microstructural evolution of rheo-diecast AZ91D magnesium alloy during heat treatment
Y Wang, G Liu and Z Fan
Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University, UK
67th World Foundry Congress
Mechanical properties and microstructural evolution of rheo-diecast (RDC)
AZ91D alloy during heat treatment (HT) have been studied. The semi-solid
processed alloy exhibits a unique solidification microstructure featuring the
uniformly distributed primary a-Mg globules, the fine secondary a-Mg
grains and the b-Mg17Al12 network. Compared with high-pressure die-cast
AZ91D alloy, the RDC alloy displays a faster solution response and
accelera...
Oct
03
2007
Mould and coremaking
AWB – an environment friendly core production technology
Th. Steinhäuser *, A. Wolff *
* Institut für angewandte Materialtechnik, Universität Duisburg - Essen, Germany
67th World Foundry Congress
The AWB core binder system is based on sodium silicate binders. The
hardening of the cores is done by dehydration, there is no chemical
reaction. This makes the hardening process reversible and reclamation
simple. Dehydration is done by a combination of heated core box, vacuum
and microwave treatment. The binder system has been widely tested at
the University Duisburg – Essen and at the labs of Hydro Aluminium. A
great number of ...
