Casting

A liquid metal is poured in a mold cavity of size $200 \mathrm{~mm} \times 200 \mathrm{~mm} \times 200 \mathrm{~mm}$. The cooling is uniform in all directions with NO additional compensation for shrinkage. Considering th...

Two metal parts (a cylinder and a cube) of same volume are cast under identical conditions. The diameter of the cylinder is equal to its height. The ratio of the solidification time of the cube to that of the cylinder is...

$$ \text { Match the mold elements in the casting process with the most suitable function } $$ Column I Column II P. Blind riser I. Casting with internal cavity Q. Chill II. Molten metal reservoir R. Skim bob III. Nuclea...

Aluminium is casted in a cube-shaped mold having dimensions as 20 mm × 20 mm × 20 mm. Another mold of the same mold material is used to cast a sphere of aluminium having a diameter of 20 mm. The pouring temperature for b...

The allowance provided to a pattern for easy withdrawal from a sand mold is

The atomic radius of a hypothetical face-centered cubic (FCC) metal is (√2/10) nm. The atomic weight of the metal is 24.092 g/mol. Taking Avogadro’s number to be 6.023 × 10 23 atoms/mol, the density of the metal is _____...

In a metal casting process to manufacture parts, both patterns and moulds provide shape by dictating where the material should or should not go. Which of the option(s) given correctly describe(s) the mould and the patter...

Consider sand casting of a cube of edge length a. A cylindrical riser is placed at the top of the casting. Assume solidification time, t s ∝ V/A, where V is the volume and A is the total surface area dissipating heat. If...

A sprue in a sand mould has a top diameter of $$20mm$$ and height of $$200mm.$$ The velocity of the molten metal at the entry of the sprue is $$0.5m/s.$$ Assume acceleration due to gravity as $$9.8\,\,m/{s^2}$$ and negle...

The part of a gating system which regulates the rate of pouring of molten metal is

A cylindrical job with diameter of $$200$$ $$mm$$ and height of $$100$$ $$mm$$ is to be cast using modulus method of riser design. Assume that the bottom surface of cylindrical riser does not contribute as cooling surfac...

Equal amounts of a liquid metal at the same temperature are poured into three moulds made of steel, copper and aluminum. The shape of the cavity is a cylinder with $$15$$ $$mm$$ diameter. The size of the moulds are such...

Gray cast iron blocks of size $$100\,\,mm \times 50\,\,mm \times 10\,\,mm$$ with a central spherical cavity of diameter $$4$$ mm are sand cast. The shrinkage allowance for the pattern is $$3\% $$. The ratio of the volume...

Ratio of solidification time of a cylindrical casting (height $$=$$ radius) to that of a cubic casting of side two times the height of cylindrical casting is ____________

A cube and a sphere made of cast iron (each of volume $$1000\,\,c{m^3}$$) were cast under identical conditions. The time taken for solidifying the cube was $$4$$ $$s.$$ The solidification time (in $$s$$) for the sphere i...

In full mould (cavity-less) casting process, the Pattern is made of

The solidification time of a casting is proportional to $${\left( {{V \over A}} \right)^2},$$ Where $$V$$ is the volume of the casting and $$A$$ is the total casting surface area losing heat. Two cubes of same material a...

An aluminium alloy (density $$2600$$ $$kg/{m^3}$$ ) casting is to be produced. A cylindrical hole of $$100$$ $$mm$$ diameter and $$100$$ $$mm$$ length is made in the casting using sand core (density $$1600$$ $$kg/{m^3}$$...

A cylindrical riser of $$6$$ $$cm$$ diameter and $$6$$ $$cm$$ height has to be designed for a sand casting mould for producing a steel rectangular plate casting of $$7cm \times 10cm \times 2cm$$ dimensions having the tot...

The hot tearing in a metal casting is due 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

A cubic casting of $$50mm$$ side undergoes volumetric solidification shrinkage and volumetric solid contraction of $$4\% $$ and $$6\% $$ respectively. No riser is used. Assume uniform cooling in all directions. The side...

Green sand mould indicates that

For the case of molding, it is decided to replace a spherical riser of diameter $$100$$ $$mm$$ by a cylindrical riser. Determine size of the cylindrical riser that will have the identical solidification time. Assume blin...

In a gating system, the ratio $$1:2:4$$ represents

Two streams of liquid metal, which are not hot enough to fuse properly, result into a casting defect known as

While cooling, a cubical casting of side $$40mm$$ undergoes $$3\% ,\,\,4\% $$ and $$5\% $$ volume shrinkage during the liquid state, phase transition and solid state respectively. The volume of metal compensated from the...

Which of the following engineering materials is the most suitable candidate for hot chamber die casting

If a particular $$Fe$$-$$C$$ alloy contains less than $$0.83$$% carbon, it is called

Volume of a cube of a side $$''l''$$ and volume of sphere of radius $$' r '$$ are equal. Both the cube and the sphere are solid and same material. They are being cast. The ratio of the solidification time of the cube to...

In a sand casting operation, the total liquid head is maintained constant such that it is equal to the mould height. The time taken to fill the mould with a top gate is $${t_A}.$$ If the same mould is filed with a bottom...

An expendable pattern is used in

A mould has a downsprue whose length is $$20$$ $$cm$$ and the cross sectional area at the base of the down sprue is $$1\,\,c{m^2}.$$ The down sprue feeds a horizontal runner leading into the mould cavity of volume $$1000...

Gray cast iron blocks $$200 \times 100 \times 10\,\,mm$$ are to be cast in sand moulds. Shrinkage allowance for pattern making is $$1$$%. The ratio of the volume of pattern to that of the casting will be

Misrun is a casting defect which occurs due to

With a solidification factor of $$0.97 \times {10^6}s/{m^2},$$ the solidification time (in seconds) for a spherical casting of $$200$$ $$mm$$ diameter is

Hardness of green sand mould increase with

The primary purpose of a sprue in a casting mold is to

In centrifugal casting, the lighter impurities are

Shrinkage allowance on pattern is provided to compensate for shrinkage when

Disposable patterns are made of

Two castings, a cube and a slab of the same material solidify under identical conditions. The volumes of the castings are equal but the slab dimensions are in the ratio of $$1:2:4$$, find the ratio of the solidification...

In a particular mold design, the down sprue has an area of Cross section of $$6.45\,\,c{m^2}$$ where the pouring basin leads into the sprue. The sprue is $$20$$ $$cm$$ long. The required metal flow rate at the top sectio...

Which of the following materials requires the largest shrinkage allowance, while making a pattern for casting?

Two castings of the same metal have the same surface area one casting is in the form of a sphere and the other is a cube. What is the ratio of the solidification time for the sphere to that of cube.

Light impurities in the molten metal are prevented from reaching the mold cavity by providing a

The pouring basin in a sand mold is $$200$$ $$mm$$ diameter $$100$$ $$mm$$ height. The mould cavity is a cube of $$125$$ $$mm$$ side and must be filled in $$25$$ seconds. The maximum velocity must ensure laminar flow int...

Centrifugally casted products have

An aluminium cube of $$10$$ $$cm$$ side has to be cast along with a cylindrical riser of height equal to its diameter. The riser is not insulated on any surface. If the volume shrinkage of aluminium during solidification...

In a green sand moulding process, uniform ramming leads to

Calculate the ratio of the solidification times of two steel cylindrical risers of sizes $$30cm$$ diameter by $$60$$ $$cm$$ in height and $$60cm$$ diameter by $$30$$ $$cm$$ in height subjected to identical conditions of...

A falk consisting of a cope and drag has the following dimensions: length $$300mm,$$ width $$200mm,$$ and total septh $$200mm$$ (cope height $$50mm$$). A $$150mm\,\, \times \,100mm\,\, \times 50mm$$ cast iron block is to...

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

Converging passage is used for feeding the liquid molten metal into the mould to

When $$1.0\% $$ plain carbon steel is slowly cooled from the molten state to $$740C,$$ the resulting structure will contain

The pressure at the in-gate will be maximum with the gating system

Increase in water content in moding sand causes

Two cubical castings of the same metal and sizes of $$2cm$$ side and $$4cm$$ side are moulded in green sand. If the smaller casting solidifies in $$2mins,$$ the expected time of solidifications of larger casting will be

The contraction allowance provided on the pattern and core boxes compensates for the following type of contraction.

A down sprue of $$180mm$$ length has diameter of $$20mm$$ at its top end. The liquid metal in the pouring cup is main-tained upto $$60$$ $$mm$$ height. What should be the theoretical diameter of down sprue at its lowest...