Casting · Production Engineering · GATE ME
Marks 1
1
The allowance provided to a pattern for easy withdrawal from a sand mold is
GATE ME 2024
2
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 pattern?
GATE ME 2023
3
Fluidity of a molten alloy during sand casting depends on its solidification range. The phase diagram of a hypothetical binary alloy of components A and B is shown in the figure with its eutectic composition and temperature. All the lines in this phase diagram, including the solidus and liquidus lines, are straight lines. If this binary alloy with 15 weight % of B is poured into a mould at a pouring temperature of 800 °C, then the solidification range is
GATE ME 2022 Set 2
4
Consider sand casting of a cube of edge length a. A cylindrical riser is placed at the top of the casting. Assume solidification time, ts ∝ V/A, where V is the volume and A is the total surface area dissipating heat. If the top of the riser is insulated, which of the following radius/radii of riser is/are acceptable?
GATE ME 2022 Set 2
5
Which of these processes involve(s) melting in metallic workpieces?
GATE ME 2022 Set 2
6
The welding process which uses a blanket of fusible granular flux is
GATE ME 2016 Set 2
7
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 that the outside temper-ature of the moulds do not increase appreciably beyond the atmospheric temperature during solidification. The sequence of solidification in the mould from the fastest to slowest is
(Thermal conductivities of steel, copper and aluminum are $$60.5, 401$$ and $$237$$ $$W/m$$-$$K,$$ respectively. Specific heats of steel, copper and aluminum are $$434, 385$$ and $$903$$ $$J/kg$$-$$K,$$ respectively. Densities of steel, copper and aluminum are $$7854, 8933$$ and $$2700$$ $$kg/{m^3},$$ respectively.)
GATE ME 2016 Set 3
8
The part of a gating system which regulates the rate of pouring of molten metal is
GATE ME 2016 Set 1
9
In full mould (cavity-less) casting process, the Pattern is made of
GATE ME 2015 Set 3
10
Match the casting defects (Group A) with the probable causes (Group B):
GATE ME 2014 Set 3
11
The hot tearing in a metal casting is due to
GATE ME 2014 Set 3
12
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
GATE ME 2013
13
Green sand mould indicates that
GATE ME 2011
14
Two streams of liquid metal, which are not hot enough to fuse properly, result into a casting defect known as
GATE ME 2009
15
Which of the following engineering materials is the most suitable candidate for hot chamber die casting
GATE ME 2007
16
An expendable pattern is used in
GATE ME 2006
17
Misrun is a casting defect which occurs due to
GATE ME 2004
18
Hardness of green sand mould increase with
GATE ME 2003
19
The primary purpose of a sprue in a casting mold is to
GATE ME 2002
20
In centrifugal casting, the lighter impurities are
GATE ME 2002
21
Shrinkage allowance on pattern is provided to compensate for shrinkage when
GATE ME 2001
22
Disposable patterns are made of
GATE ME 2000
23
Which of the following materials requires the largest shrinkage allowance, while making a pattern for casting?
GATE ME 1999
24
Light impurities in the molten metal are prevented from reaching the mold cavity by providing a
GATE ME 1996
25
Centrifugally casted products have
GATE ME 1993
26
In a green sand moulding process, uniform ramming leads to
GATE ME 1992
27
Converging passage is used for feeding the liquid molten metal into the mould to
GATE ME 1991
28
When there is no room temp change, the total shrinkage allowance on a pattern is INDEPENDENT OF
GATE ME 1991
29
The pressure at the in-gate will be maximum with the gating system
GATE ME 1990
30
Chills are used in molds to
GATE ME 1989
31
Increase in water content in moding sand causes
GATE ME 1989
32
The contraction allowance provided on the pattern and core boxes compensates for the following type of contraction.
GATE ME 1988
33
Riser is designed so as to
GATE ME 1987
Marks 2
1
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 both cases is the same. The ratio of the solidification times of the cube-shaped mold to the spherical mold is _______ (answer in integer).
GATE ME 2024
2
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 neglect all losses. If the mould is well ventilated, the velocity (upto $$3$$ decimal points accuracy) of the molten metal at the bottom of the sprue is ______________________ $$m/s.$$
GATE ME 2017 Set 1
3
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 of the pattern to volume of the casting is ___________________
GATE ME 2016 Set 2
4
Heat is removed from a molten metal of mass $$2$$ $$kg$$ at a constant rate of $$10$$ $$kW$$ till it is completely solidified. The cooling curve is shown in the figure.
Assuming uniform temperature throughout the volume of the metal during solidification, the latent heat of fusion of the metal (in $$kJ/kg$$) is ______________
GATE ME 2016 Set 1
5
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 surface. If the diameter of the riser is equal to its height, then the height of the riser (in $$mm$$) is
GATE ME 2016 Set 1
6
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 is _____________________
GATE ME 2015 Set 2
7
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 and size are cast using sand casting process. The top face of one of the cubes is completely insulated. The ratio of the solidification time for the cube with top face insulated to that of the other cube is
GATE ME 2015 Set 1
8
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 ____________
GATE ME 2015 Set 3
9
The dimensions of a cylindrical side riser (height $$=$$ diameter) for a
$$25cm \times 15cm \times 5cm$$ steel casting are to be determined. For the tabulated shape factor values given below, the diameter of the riser (in $$cm$$) is _______________
$$25cm \times 15cm \times 5cm$$ steel casting are to be determined. For the tabulated shape factor values given below, the diameter of the riser (in $$cm$$) is _______________
GATE ME 2015 Set 3
10
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 total solidification time of $$1.36$$ minute. The total solidification time (in minute) of the riser is ___________________
GATE ME 2014 Set 4
11
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 $$1600$$ $$kg/{m^3}$$ ). The net buoyancy force (in Newton) acting on the core is _____________________
GATE ME 2014 Set 1
12
A cylindrical blind riser with diameter $$d$$ and height $$h,$$ is placed on the top of the mold cavity of a closed type sand mold as shown in the figure. If the riser is of constant volume, then the rate of solidification in the riser is the least when the ratio $$h:d$$ is 
GATE ME 2014 Set 3
13
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 of cube after solidification and contraction is
GATE ME 2011
14
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 blind risering & ratio of height to radius of cylinder is $$2.$$
GATE ME 2010
15
In a gating system, the ratio $$1:2:4$$ represents
GATE ME 2010
16
Match the following
GATE ME 2009
17
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 riser is
GATE ME 2008
18
If a particular $$Fe$$-$$C$$ alloy contains less than $$0.83$$% carbon, it is called
GATE ME 2007
19
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 the same of the sphere is
GATE ME 2007
20
A $$200$$ $$mm$$ long down sprue has an area of cross section of $$650$$ $$m{m^2}$$ where the pouring basin meets the down sprue (i.e. at the beginning of the down sprue). A constant head of molten metal is maintaining by the pouring basin. The molten metal flow rate is $$6.5 \times {10^5}\,\,\,m{m^3}/s.$$ considering the end of down sprue to be open to atmosphere and an acceleration due to gravity of $${10^4}mm/{s^2},$$ the area of the down sprue in $$m{m^2}$$ at its end (avoiding aspiration effects) should be
GATE ME 2007
21
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 gate, then the time taken is $${t_B}.$$ Ignore the time required to fill the runner and frictional effects. Assume atmospheric pressure at the top molten metal surfaces. The relation between the $${t_A}$$ and $${t_B}$$ is
GATE ME 2006
22
Match List - $${\rm I}$$ (products) with List - $${\rm II}$$ (casting process) and select the correct answer using the codes given below the lists
GATE ME 2005
23
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 $$1000\,\,c{m^3}.$$ The time required to fill the mould cavity will be
GATE ME 2005
24
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
GATE ME 2004
25
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
GATE ME 2003
26
Match the following
GATE ME 1998
27
Only $$4$$ pairs can be matched :
GATE ME 1994
28
Match the following:
GATE ME 1992
29
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
GATE ME 1989
Marks 4
1
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 times of the cube to that of the slab.
GATE ME 2000
2
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.
GATE ME 1998
3
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 cooling
GATE ME 1992
4
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 end to ensure that there is no aspiration effects.
GATE ME 1987
Marks 5
1
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 section of the sprue is $$820$$ $$c{m^3}/s.$$ Determine the pouring height necessary above the sprue top. Also determine the area of $$C.S$$ of sprue at its bottom to avoid the aspiration of liquid molten metal.
GATE ME 1999
2
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 into the mould cavity and in the gates of circular cross-section. Design the sprue to avoid aspiration effects.
Assume
(a) constant temperature,
(b) no loss in the velocity head and
(c) diameter of gate $$=8$$ times diameter at the sprue base.
Properties of the molten metal are $$\gamma = 0.9\,\,m{m^2}$$ per second, $$\rho = 700\,\,kg/{m^3},$$ & $${C_p} = 33.6\,\,J/mol$$-$$K.$$ The diameter of sprue to avoid aspiration effect.
GATE ME 1996
3
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 is $$6\% $$, calculate shrinkage volume of cube on solidification and minimum size of the riser so that it can provide the shrinkage volume.
GATE ME 1993