Glossary
A
- Aluminium casting alloys
- Aluminium casting is dominated by the automotive industry. Roughly two thirds of all aluminium castings are automotive where the use of aluminum castings continues to grow at the expense of iron castings.
- Aluminium Oxide
- The density of aluminium oxide is close to that of the metal itself so oxide inclusions may not all float to the surface
B
- Bottom Pour Ladles
- The ladle is fitted with a pouring nozzle in its base, closed by a refractory stopper rod
C
- Compacted Graphite Irons
- Compacted graphite (CG) irons are a range of cast irons having mechanical properties intermediate between those of grey and ductile irons.
D
- Dross
- The dross consists of magnesium silicate films and magnesium sulphide particles.
G
- Gas porosity
- Gas porosity refers to the presence of small voids or pores within a solid metal structure that are filled with gas, typically occurring during the casting or solidification process of metal alloys.
L
- Linings Break Off
- The refractory linings of cold blast cupolas have a short life of less than 24 hours, so cupolas are operated in pairs, each used alternately while the other is re-lined.
- Lip Pour Ladles
- In this type of ladle the metal is discharged over the lip, flow is controlled by tilting the ladle using a geared handwheel
- Lustrous Carbon
- The heating of the coal dust by the liquid iron causes the formation of a type of carbon called lustrous carbon
M
- Magnesium casting alloys
- Magnesium alloy castings are used for aerospace, automotive and electronic applications. Their main advantage is their light weight.
- Metal penetration
- A physical effect at the sand/metal interface when liquid metal is cast into a sand mould or against a core. It either may result in surface defects on the finished casting.
N
- Non-metallic inclusions
- The term ‘non-metallic inclusions’ covers a range of casting defects with a range of causes.
P
- Pinholes
- This iron casting defect consists of small sub-surface holes which can be seen in a casting fracture or on the casting surface after shot blasting, heat treatment or light machining.
S
- Sand Inclusions
- Sand inclusions are from loose moulding sand or sand erosion.
- Self-hardening process
- In the self-hardening process clean, dry sand is mixed with binder and catalyst, usually in a continuous mixer. The mixed sand is vibrated or hand-rammed around the pattern or into a core box; binder and catalyst react, hardening the sand.
- Shrinkage
- During the cooling and solidification of most metals and alloys, there is a reduction in the metal volume known as shrinkage.
- Silicate Binders
- Silicate binders, also commonly known as water glass, are probably the oldest core and mould binders used in the foundry industry
- Slag
- Slag is formed in electric melting furnaces from the products of oxidation of the elements in the charge, particularly the iron, silicon and manganese; from refractory erosion and from dirt, sand or rust on the charge.
- Steel castings
- Steel castings range in size from a few grams to hundreds of tonnes. Steel castings are often used in critical situations where optimum mechanical properties are essential so that freedom from casting defects is particularly important.
T
- Teapot Ladles
- A refractory dam before the ladle lip ensures that metal is drawn from the bottom of the ladle so that the stream is slag free
V
- Veining
- Veining defects arise from metal entering cracks in the core surface which form as a result of the thermal stresses generated by the expansion of silica sand during casting