Horizontal true centrifugal casting is used to make aluminum rings with length = 5 cm, outside diameter = 65 cm, and inside diameter = 60 cm. (a) Determine the rotational speed that will provide a G-factor = 60. (b) Suppose that the ring were made out of steel instead of aluminum. If the rotational speed computed in part (a) were used in the steel casting operation, determine the G-factor and (c) centrifugal force per square meter (Pa) on the mold wall. (d) Would this rotational speed result in a successful operation? The density of steel = 7.87 g/cm3

a) 423 rpm

b) G-factor = 60

c)

d) Yes, it would result in a successful operation

Explanation:

Given that:

length of aluminium ring = 5 cm

outside diameter = 65 cm

inside diameter = 60 cm

rotational G - factor = 60

G- factor =

G- factor =

G- factor =

where v = r ω  and ω =

G- factor =

G- factor =

N = 423 rpm

b) However, the material is steel and N = 423 rpm

∴ 423 ⇒

G-factor = 60

Thus, the G-factor is independent of the material

c) Centrifugal force per square meter is expressed as:

where; F =

Also; m = ρ. V

and  V = A. l

∴

 where;

ρ = 7.87 g/cm ³

ρ = 7870 kg/m³

d)

The rotational speed will possibly result into a successful operation. This is so because the range of speed of operation of centrifugal casting is between (300- 3000) rpm and N = 423 rpm which tells us that; it is still in range and will definitely result into a successful operation.

the current is 0.6

voltage ÷ resistance = current

so 12 ÷ 20 = 0.6