article icon
Science, Maths & Technology
Low pressure die casting (counter-pressure casting)
Low pressure air is introduced into a sealed furnace holding a tank of molten metal. The metal feeds up slowly through a riser tube and into the die cavity. Once the casting has solidified in the die, air pressure is released, allowing any residue molten metal still in the riser to fall back into the tank for recycling. When cooled, the casting ...
article icon
Money & Business
Banks as utilities and the future of payments
In a wide-ranging discussion, Ecobank's Edward George shares his personal views about the future of banks, and digital strategy across African markets.
article icon
Science, Maths & Technology
High pressure die casting
Molten metal is forced into a metal die at a high pressure. There are two main types: “cold-chamber” and “hot-chamber” processes.
article icon
Science, Maths & Technology
Gravity die casting
Molten material is gently poured into a mould, using only the forces of gravity, then left to solidify.
article icon
Science, Maths & Technology
CLA – Hitchiner process
A vacuum is applied to a hollow investment mould sealed within a chamber, causing molten metal to rise upwards into the hollow. The vacuum is released when the metal has solidified. Chandler-Lamb were the originators, and Hitchiner is the company.
article icon
Science, Maths & Technology
Ceramic mould casting
Ceramic slurry is poured over a relief pattern and left to solidify, forming a cavity mould in the shape of the component to be cast. Cope and drag parts are produced. Each ceramic part is hardened by high temperature firing, then fitted together to make one hollow mould in which to cast the molten metal.
article icon
Science, Maths & Technology
Resin shell casting
A thin shell of resin-bonded sand is formed around a heated metal pattern. Separating the shell from the pattern and clamping it to a mating shell forms a complete mould into which metal can be cast.
article icon
Science, Maths & Technology
Investment casting
A temporary initial pattern is made from wax. The mould, or investment, is made by dipping the wax pattern into a vat of refractory slurry, which solidifies around the outside of the wax pattern. This process is repeated until the required wall thickness is achieved. The original wax pattern is then melted away, leaving a hollow mould in which ...
video icon
Science, Maths & Technology
Hallowain't III: Thorny devil
It's a spiky devil. It's also known as a dragon. So is it a dragon from hell? No.
video icon
Science, Maths & Technology
Blue Planet II - One Ocean: The videos
Get a taste of episode one, and go behind the scenes, of our lush love letter to the deep blue.
video icon
Nature & Environment
Hallowain't III: Woodfrogs
A block of ice melts away, and there sits a frog. Is this an ice monster of some sort? No.
video icon
Nature & Environment
Hallowain't III: Vampire squid from hell
Is there something truly demonic about the vampire squid from hell? No.