Metallurgy for Dummies

Aerospace alloys

The addition of scandium to aluminium creates nanoscale Al3Sc precipitates which limit the excessive grain growth that occurs in the heat-affected zone of welded aluminium components. This has two beneficial effects: the precipitated Al3Sc forms smaller crystals than are formed in other aluminium alloys and the width of precipitate-free zones that normally exist at the grain boundaries of age-hardenenable aluminium alloys is reduced.

Parts of the Mig–29 are made from Al-Sc alloy

Scandium is also a potent grain refiner in cast aluminium alloys, and atom for atom, the most potent strengthener in aluminium, both as a result of grain refinement and precipitation strengthening. However, titanium alloys, which are stronger but heavier, are cheaper and much more widely used.

(continue reading…)

You might also like

Precipitation Hardening Precipitation Hardening Overview Precipitation...

What are Magnesium Alloys ? Magnesium Alloys Magnesium alloys are mixtures...

What is Superalloy ? What is Superalloy ? - Definition and Meaning A...

How does Friction Welding Work ? What is Friction Welding ? Friction welding...

Friction Stir Welding – How Does It Works ?

Friction stir welding, a process invented at TWI, Cambridge, involves the joining of metals without fusion or filler materials. The welds are created by the combined action of frictional heating and mechanical deformation due to a rotating tool. The probe penetrates the workpiece whereas the shoulder rubs with the top surface.

The heat is generated primarily by friction between a rotating–translating tool, the shoulder of which rubs against the workpiece. There is a volumetric contribution to heat generation from the adiabatic heating due to deformation near the pin. The microstructure of a friction-stir welddepends in detail on the tool design, the rotation and translation speeds, the applied pressure and the characteristics of the material being joined. The heat-affected zone (HAZ) is as in conventional welds.

(continue reading…)

You might also like

How does Friction Welding Work ? What is Friction Welding ? Friction welding...

Welding Pictures Welding Pictures Welding is a fabrication or sculptural process that...

What is Plastic Welding ? Welding Plastic Definition Plastic welding...

Welding What is Welding ? Welding is a fabrication...

The Moon Surface Materials

The bulk density of the Moon is 3.4 g/cc, which is comparable to that of (volcanic) basaltic lavas on the Earth (however, the bulk density of the Earth is 5.5 g/cc, because of the dense iron/nickel core).

The Lunar

The Moon is coverered with a gently rolling layer of powdery soil with scattered rocks that is called the regolith; it is made from debris blasted out of the Lunar craters by the meteor impacts that created them. Each well-preserved Lunar crater is surrounded by a sheet of ejected material called the ejecta blanket.

(continue reading…)

You might also like

Futuristic Materials part 2 Aerogel Several really amazing things to...

Meteorite What is a meteorite material ? A meteorite...

What is Fiber Optic? Fiber Optic - a Definition An optical fiber...

Composite Materials  What is Composite Materials ? Composite...