The machining of titanium is difficult due to
High thermal conductivity of titanium
Chemical reaction between tool and work
Low tool-chip contact area
None of these
Correct Answer :
C. Low tool-chip contact area
Related Questions
The silicon carbide abrasive is chiefly used for grinding
Cemented carbide
Ceramic
Cast iron
All of these
In a shaper, the metal is removed during
Forward stroke
Return stroke
Both the forward and return strokes
Neither the forward nor the return stroke
The method of centre less grinding used to produce taper is
In-feed grinding
Through feed grinding
End feed grinding
Any one of these
The strength of a brazed joint
Decreases with increase in gap between the two joining surfaces
Increases with increase in gap between the two joining surfaces
Decreases up to certain gap between the two joining surfaces beyond which it increases
Increases up to certain gap between the two joining surfaces beyond which it decreases
Which of the following statement is correct as regard to up milling?
It cannot be used on old machines due to backlash between the feed screw of the table and the nut.
The chips are disposed off easily and do not interfere with the cutting.
The surface milled appears to be slightly wavy.
The coolant can be poured directly at the cutting zone where the cutting force is maximum.
Which of the following statement is correct about hot machining?
It requires less power than machining metals at room temperature.
The rate of tool wear is lower.
It is used for machining high strength and high temperature resistant materials.
All of the above
Gear lapping is an operation
After heat treatment
Prior to heat treatment
For gear reconditioning
None of these
Tool life is generally better when
Grain size of the metal is large
Grain size of the metal is small
Hard constituents are present in the microstructure of the tool material
None of the above
A drill bit of 20 mm diameter rotating at 500 r.p.m. with a feed rate of 0.2 mm/revolution is used to drill a through hole in a mild steel plate 20 mm thickness. The depth of cut in this drilling operation is
0.2 mm
10 mm
20 mm
100 mm
In a milling operation, two side milling cutters are mounted with a desired distance between them so that both sides of a workpiece can be milled simultaneously. This set up is called
Gang milling
Straddle milling
String milling
Side milling
Two streams of liquid metal which are not hot enough to fuse properly result into a casting defect known as
Cold shut
Swell
Sand wash
Scab
The tool life in case of a grinding wheel is the time
Between two successive regrinds of the wheel
Taken for the wheel to be balanced
Taken between two successive wheel dressings
Taken for a wear of 1 mm on its diameter
A taper tap has
Its end tapered for about three or four threads
Its end tapered for about eight or ten threads
Full threads for the whole of its length
None of the above
Ultrasonic machining is best suited for
Tool steels
Sintered carbides
Glass
All of these
Stellite preserves hardness upto a temperature of
350°C
500°C
900°C
1100°C
When two main plates are kept in alignment butting each other and riveted with cover plate on both sides of the main plates with two rows of rivets in each main plate, the joint is known as _______ double cover butt joint.
Single riveted
Double riveted
Both (A) and (B)
None of these
Surface grinding is done to produce
Tapered surface
Flat surface
Internal cylindrical holes
All of these
The relief or clearance at the cutting edge of a flat drill varies from
3° to 8°
20° to 30°
60° to 90°
90° to 120°
In an interchangeable assembly, shafts of size 25.000 -0.0100⁺⁰⁰⁴⁰ mm mate with holes of size 25.000 -0.010⁺⁰⁰²⁰ mm. The maximum possible clearance in the assembly will be
10 microns
20 microns
30 microns
60 microns
The hole to be drilled for tapping is _________ the outside diameter of the thread on the tap.
Equal to
Smaller than
Greater than
None of these
In ultrasonic machining, tool is made of
Tungsten carbide
Brass or copper
Diamond
Stainless steel
In a metal arc welding process, metal transfer across the arc may take place by a method of material transfer where the metal transfers across the arc is in larger drops. This is at the rate of 100 drops / sec or less, what is this known as
Globular transfer
Spray transfer
GMAW practice
Dip transfer
Trepanning is an operation of
Making a cone-shaped enlargement of the end of a hole
Smoothing and squaring the surface around a hole
Sizing and finishing a small diameter hole
Producing a hole by removing metal along the circumference of a hollow cutting tool
The binding material used in cemented carbide tools is
Tungsten
Chromium
Silicon
Cobalt
In a shaper
Tool is stationary and work reciprocates
Work is stationary and tool reciprocates
Tool moves over stationary work
Tool moves over reciprocating work
In up-cut milling the work piece is fed
Against the rotating cutter
At angle of 60° to the cutter
In the direction of the cutter
At the right angle to the cutter
In electro-discharge machining, dielectric is used to
Help in the movement of the sparks
Control the spark discharges
Act as coolant
All of these
Misrun is a casting defect which occurs due to
Very high pouring temperature of the metal
Insufficient fluidity of the molten metal
Absorption of gases by the liquid metal
Improper alignment of the mould flasks
In a CNC program block, N002 GO2 G91 X40 Z40......, GO2 and G91 refer to
Circular interpolation in counter clockwise direction and incremental dimension
Circular interpolation in counter clockwise direction and absolute dimension
Circular interpolation in clockwise direction and incremental dimension
Circular interpolation in clockwise direction and absolute dimension
Which of the following statement is correct regarding grinding of high carbon steel?
Grinding at high speed results in the reduction of chip thickness and cutting forces per grit.
Aluminium oxide wheels are employed.
The grinding wheel has to be of open structure.
All of the above