Manufacturing Technology MCQs | Page - 29

 true centrifugal casting method is usually used to make ‘hollow pipes and tubes’.

 in centrifugal casting, mould is rotated rapidly about its central axis as the metal is poured into it. because of the centrifugal force, continuous pressure is applied to the metal as it solidifies. the slag and the other inclusions being lighter gets separated from the metal and segregates toward the centre.

 specifically, true centrifugal casting is generally used for the making of hollow pipes and tubes, which are axi- symmetric with a concentric hole. molten metal is accumulated at the inward surface of the mould by the rotation of the mould and then the solidification of a melt is taking place.

 in centrifugal casting, there is no requirement of any core for the making of the concentric hole. as the metal is always pushed outward because of the centrifugal force, application of core is eliminated. only the oxides and slag part separate from the metal and segregate at the centre.

 in centrifugal casting, the axis of rotation of the mould can be horizontal, vertical or any angle in between. generally, very long pipes are cast with a horizontal axis, whereas short pieces are more conveniently cast with a vertical axis, as it requires less area for the casting operation.

 not only sand moulds, the metallic moulds can also be used in the centrifugal casting process for large scale production. as inducing of high temperature of metallic mould can be avoided by water circulation through it and sticking problem can also be solved by casting of non-sticking materials.