1
GATE PI 2003
+5
-1.5
The following data refers to an orthogonal machining of mild steel with a single point $$HSS$$ tool. Rake angle of tool $$= {10^ \circ },$$ uncut chip thickness $$=0.3mm,$$ width of cut $$=2.0mm,$$ single plane shear angle $$= {36^ \circ },$$ shear strength of mild steel $$=450$$ $$MPa,$$ using Merchants analysis

The coefficient of friction between the chip and tool will be

A
$$0.141$$
B
$$0.344$$
C
$$0.532$$
D
$$0.688$$
2
GATE PI 2003
+5
-1.5
The following data refers to an orthogonal machining of mild steel with a single point $$HSS$$ tool. Rake angle of tool $$= {10^ \circ },$$ uncut chip thickness $$=0.3mm,$$ width of cut $$=2.0mm,$$ single plane shear angle $$= {36^ \circ },$$ shear strength of mild steel $$=450$$ $$MPa,$$ using Merchants analysis

The shear force in cutting will be

A
$$270$$ $$N$$
B
$$333.75$$
C
$$450$$ $$N$$
D
$$459.34$$ $$N$$
3
GATE PI 2002
Subjective
+5
-0
A cutting tool is designated in 'Orthogonal Rake System' as: $${0^ \circ } - {0^ \circ } - {6^ \circ } - {6^ \circ } - {25^ \circ } - {75^ \circ } - 0.8\,\,mm.$$\$
The following data were given
$${S_0} =$$ feed $$=0.12$$ $$mm/rev$$
$$T=$$ depth of cut $$=2.0$$ $$mm$$
$${a_2} =$$ chip thickness $$=0.22$$ $$mm$$
$${V_f} =$$ chip velocity $$=52.6$$ $$m/min$$
$${\tau _s} =$$ dynamic yield shear strength $$=400$$ $$MPa$$
$${P_z} =$$ main cutting force $$= {S_0}\,t\,{\tau _s}\left( {\zeta \,\sec y - \tan \gamma + 1} \right)$$

Where $$\zeta =$$ chip reduction coefficient and $$\gamma =$$ orthogonal rake.
The main cutting force $$\left( {{P_z}} \right)$$ and cutting power assuming orthogonal machining are

4
GATE PI 2001
Subjective
+5
-0
In certain machining operation with a cutting speed of $$50$$ $$m/min,$$ tool life of $$45$$ minutes was observed, when the cutting speed was increased to $$100$$ $$m/min,$$ the tool life decreased to $$10$$ minutes. The cutting speed for maximum productivity, if tool change time is $$2$$ minutes is
GATE PI Subjects
Fluid Mechanics
Metrology
Theory of Machines
Engineering Mathematics
Heat Transfer
Machine Tools and Machining
Industrial Engineering
Engineering Mechanics
Strength of Materials
Thermodynamics
Machine Design
Casting
Joining of Materials
Metal Forming
EXAM MAP
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