Casting Process · Casting · GATE PI

In carbon dioxide molding process, the binder used is

Match the items in the first column to their functions in the second column.

Chills are used in casting moulds to

A cube shaped casting solidifies in $$5$$ min. The solidification time in min for a cube of the same material, which is $$8$$ times heavier than the original casting, will be

In sand casting fluidity of the molten metal increases with

Which of the following casting processes uses expandable pattern and expandable mold

Solidification time of a metallic alloy casting is

Hot chamber die casting is NOT suited for

In hollow cylindrical parts made by centrifugal casting, the density of the part is

Cold shut is a defect in casting due to

An expandable pattern is used in

Wood flour is added to core sand to improve:

Which one of the following is NOT a property of a sand mold?

Shell molding is an investment casting process $$(T/F)$$

Bentonite is commonly used bonding material for dry sand cores

Investment casting uses ...... A........... as pattern material and is preferred for small parts with .......... B.........designs.

A. wax / resin coated sand
B. simple / intricate

Chaplets are placed between mold in order to

Investment casting uses ......... (wax / resin coated sand) as pattern material and is preferred for small parts with ................. (simple/intricate) designs

Increase in carbon content in plain carbon steels raise its

The primary function of a riser is to

Pressure die casting deals with casting metals of relatively ............. A ............. melting point and provides ........ B.......... production rate.

A. higher / lower,$$\,\,\,\,\,\,\,\,\,\,$$ B. higher / lower

The optimum pouring time for a casting depends on several factors. One important factor among them is

Ceramic slurry is used in making the molds for

Low permeability molds and low pouring temperature of the molten metal causes ......................... defect in castings.

For casting of turbine blades made of high temp and high strength alloys, the most suitable process is

The problem of shrinkage cavity is more likely to occur while casting ......... A ............ B.......... a chill block

(A.) metal / plastic , (B.) with / without.

For the same material, powder metallurgy process is superior to casting for

Poor collapsibility of the mold leads to .......... type of casting defect in aluminium castings.

The process by which shell like castings (like toys) are made is

Green strength in powder metallurgy refers to the strength of

Negative allowance is provided on the pattern to take care of

Schematic diagram of pouring basin and sprue of a gating system is shown in the Figure. Depth of molten metal in the pouring basin is $$100$$ $$mm$$ and the height of the sprue is $$1,500$$ $$mm.$$

Considering the cross-section of the sprue is circular, the ratio $${d_1}:{d_2}$$ to avoid aspiration is

Two cast iron blocks $$P$$ and $$Q,$$ each of $$500$$ $$mm$$ length, have the same cross-sectional area. Block $$P$$ has rectangular cross-section of $$100\,\,mm \times 200\,\,mm.$$ Block $$Q$$ is of square cross-section. Both $$P$$ and $$Q$$ were cast under the same conditions with all their surfaces enclosed within the mould. The solidification time of a casting is proportional to the square of the ratio of its volume to its surface area. The ratio of solidification time of the block $$P$$ to that of the block $$Q$$ is _________________

In a metal casting process, molten copper alloy is poured into a sand mould. The level of molten metal in the pouring basin is at a height of $$300$$ $$mm$$ from the runner having diameter of $$10$$ $$mm.$$ If the density and melting temperature of molten copper alloy are $$9000$$ $$kg/{m^3}$$ and $${1000^ \circ }C.$$ respectively then the rate of flow of molten metal into the mould neglecting friction and other losses, in $$c{m^3}/s,$$ is ______________.

For a given volume of a riser, if the solidification time of the molten metal in riser needs to be quadrupled, the surface area of the riser should be made

A mold having dimensions $$100 \times 90 \times 20$$ (all in $$mm$$) is filled with molten metal througgh a gate with height $$'h'$$ and $$C.S$$ area $$A,$$ the mould filling time is $${t_1}$$. The height is now quadrupled and the cross sectional area is halved. The corresponding filling time is $${t_2}$$. The ratio $${t_2}/{t_1}$$ is

In a sand casting process, a sphere and a cylinder of equal volumes are separately cast from the same molten metal under identical conditions. The height and diameter of the cylinder are equal. The ratio of the solidification time of the sphere to that of the cylinder is

During the filling process of a given sand mould cavity by metal through a horizontal runner of circular $$C.S,$$ the frictional head loss of the molten metal in the runner will increase with the

A solid cylinder of diameter $$D$$ and height equal to $$D,$$ and a solid cube of side $$L$$ are being sand cast by using the same material. Assuming there is no super-heat in both the cases, the ratio of solidification times of the cylinder to the solidification time of the cube is

In sand casting of hallow part of lead, a cylindrical core of diameter $$120mm$$ and height $$180mm$$ is placed inside the mould cavity. The densities of core material and lead are $$1600kg/{m^3}$$ and $$11300kg/{m^3}$$ respectively. The net force (in $$N$$) that tends to lift the core during pouring of molten metal will be

In a sand casting process, a sprue of $$10mm$$ base diameter and $$250mm$$ height leads to a runner which fills a cubical mold cavity of $$100mm$$ size.

The mold filling time in seconds is

Match the following

In a sand casting process, a sprue of $$10mm$$ base diameter and $$250mm$$ height leads to a runner which fills a cubical mold cavity of $$100mm$$ size.

The volume flow rate (in $$m{m^3}/s$$) is

A casting of size $$400mm \times 200mm \times 140mm$$ solidifies in $$20min.$$ The solidification time for a casting $$400mm \times 200mm \times 35mm$$ under similar conditions is

A cast steel slab of dimension $$30 \times 20 \times 5\,\,cm$$ is poured horizontally using a side riser. The riser is cylindrical in shape with diameter and height, both equal to $$D.$$ The freezing ratio of the moulds is

The shape factor for a casting in the form of an annular cylinder of outside diameter $$30$$ $$cm,$$ inside diameter $$20$$ $$cm$$ and height $$30$$ $$cm$$ (correction factor $$k=1.0$$) will be

Match the items of List $${\rm I}$$ (Equipment) with the items of List $${\rm II}$$ (Process) and select the correct answer using the given codes

Chapters are placed between mould and core surfaces in order to :

Gating ratio of $$1:2:4$$ is used to design the gating system for magnesium alloy casting. This gating ratio refers to the cross section areas of the various gating elements as given below

$$1.$$ $$Down$$ $$sprue$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$2.$$ $$runner$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$3.$$ $$Ingates$$
The sequence of the above elements in the ratio $$1:2:4$$ is

A casting of size $$100\,\,mm \times 100\,\,mm \times 50\,\,mm$$ is required. Assume volume shrinkage of casting $$2.6\% $$. If the height of the riser is $$80$$ $$mm$$ and riser volume desired is $$4$$ times the shrinkage in casting, what is the appropriate riser diameter in $$mm?$$

A $$10$$ $$mm$$ thick steel bar is to be horizontally cast with two correctly spaced top risers of adequate feeding capacity. Assuming end effect without chill, what should be the theoretical length of the bar?

The permeability of molding sand was determined using a saturated $$AFS$$ sample by passing $$2000cc$$ of air at a gage pressure of $$10$$ $$g/c{m^2}$$. If the time taken for the air to escape was $$1$$ min, the permeability number is:

Proper gating design in metal casting

$$P:$$ Influences the freezing range of the melt
$$Q:$$ Compensates the loss of fluidity of the melt
$$R:$$ Facilitates top feeding of the melt
$$S:$$ Avoids misrun

The height of the down sprue is $$175$$ $$mm$$ and its $$CS$$ area at the base is $$200\,\,m{m^2}.$$ The $$CS$$ area of the horizontal runner is also $$200$$ $$m{m^2}$$. Assuming no losses, indicate the correct choice for the time (seconds) required to fill a mold cavity of volume $${10^6}\,\,m{m^3}.$$ (use $$g=10$$ $$m/{s^2}$$)

Match the cast defect with their cause

According to Chvorinove's rule, the solidification time of a casting is proportional to [Volume/Surface area]ⁿ where $$n=....$$

Match the application with type of pattern

When there is no room temp change, the total shrinkage allowance on a pattern is INDEPENDENCE OF

What is the velocity of the steel at the bottom of the sprue if the sprue height is $$30$$ $$cm$$? Assume the frictional and other losses to be $$20\% $$

Shrinkage allowance on pattern is provided to compensate for shrinkage when

For true centrifugal casting process with the axis of rotation in horizontal direction, an acceleration of $$75g,$$ where $$g$$ is the acceleration due to gravity, is required for sound casting. The relation between diameter. $$'D'$$ (in $$mm$$) and the rotational speed $$N$$ ($$1$$ $$rev/s$$) for this casting is $${N^2}D = $$ constant, determine the constant. Also calculate the mold speed (in $$rev/sec(c)$$ for casting $$CI$$ pipes of $$5m$$ long with outside and inside diameters of $$0.52m$$ and $$0.5m$$ respectively

A cylinder of $$150mm$$ diameter & $$200mm$$ height is to be cast with out any riser. The cylinder is moulded entirely in the drag of a green sand flask & is top gated. The cope of the flask is $$200mm$$ height & the height of the metal during pouring is $$50mm$$ above the cope. A tapered sprue is employed & the gating ratio is $$1:1.5:2$$. The time taken (in seconds) to fill the casting cavity neglecting energy losses, if the in-gate area is $$400sq.mm$$

A casting of $$200\,\,mm\,\, \times \,\,100\,\,mm \times 70\,\,mm$$ size solidifies in ten minutes. Estimate solidification time for a $$200\,\,mm\,\, \times \,\,100\,\,mm \times 10\,\,mm$$ casting under similar conditions?

If the freezing ratio equal to (casting area/casting volume)/(riser area/riser volume) & the volumetric ratio equal to riser volume/casting volume, for a disc casting of $$20cm$$ diameter and $$10$$ $$cm$$ thick are $$1.4$$ and $$0.8$$ respectively. The corresponding values for a square disc of $$20$$ $$cm$$ side and $$10$$ $$cm$$ thick if the same cylindrical riser with a height to diameter ratio of unity is used in both cases.

Molten aluminium was poured in a sand mold and the thickness of solid skin formed after $$20$$ seconds and $$50$$ seconds were fond to be $$3mm$$ and $$4.5mm$$ respectively. What would be the thickness of the solid skin at the end of $$100$$ seconds after pouring?

Three castings are of the same material, volume and cast under similar conditions. One is a sphere, another is a cube and the third is cylinder with its length being equal to its diameter.

The ratio of solidification times of sphere to the cube is

Three castings are of the same material, volume and cast under similar conditions. One is a sphere, another is a cube and the third is cylinder with its length being equal to its diameter.

The solidification time of the sphere to the cylinder

A rectangular block of steel $$C.S$$ $$100\,\, \times \,\,150mm$$ and $$250mm$$ height is to be cast with out any riser. The block is moulded entirely in the drag of a green sand flask & is tap gated. The cope of the flask is $$200mm$$ height & the height of the metal during pouring is $$100mm$$ above the cope level. A tapered sprue is employed & the gating ratio is $$1:4:2$$. Assume no energy losses in the system. The time taken (in seconds) to fill the casting cavity, if the tapered sprues with $$500$$ $$m{m^2}$$ exit area is used.

A steel plate $$40cm \times 30cm \times 0.3cm$$ is to be cast. The volume shrinkage of steel during solidification is $$3\% .$$ A cylindrical side riser with diameter $$4cm$$ and height $$4cm$$ is used. The riser volume should at least be $$3$$ times that the dictated by shrinkage consideration. Is the riser volume sufficient if not what is the riser size?