Engineering Questions with Answers - Multiple Choice Questions
Manufacturing Processes – Friction Welding – 2
1 - Question
Friction welding process is restricted to_____
a) square bars
b) round bars
c) hexagonal bars
d) bars having diameters less than 20mm
Explanation: The process is restricted to joining round bars of same diameter (or bar tubes to flat surfaces), i.e., capable of being rotated about the axis. Furthermore, capital equipment and tooling costs are high and free-machining alloys are difficult to weld.
2 - Question
Which of the following materials cannot be welded by friction welding?
c) Stainless steel
d) Non-forgeable materials
Explanation: Dry bearing and non-forgeable materials cannot be welded by a friction welding process, i.e., one of the components must be ductile when hot, to permit deformations. Preparation and alignment of the workpieces of the workpieces may be critical for developing for developing uniform rubbing and heating, particularly for pieces having diameters larger than 50mm.
3 - Question
In which of the following areas, friction welded products are not used?
d) Toy making
Explanation: Friction welded parts in production application span over wide products for aerospace, agriculture, automotive, defence, marine and oil industries. Right from tong holds to critical aircraft engine components are friction welded in production.
4 - Question
Which of the following automotive components are not friction-welded?
b) Engine valves
c) Strut rods
Explanation: Automotive parts that are friction welded include gears, engine valves, axel tubes, driveline components, strut rods and shock absorbers. Rims are generally welded by TIG or MIG welding.
5 - Question
Friction welding cannot be used for welding stainless steel to carbon steels.
Explanation: Stainless steels are friction welded to carbon steels in various sizes for uses in marine systems and water pumps for home and industrial use. Friction welded aluminium/copper joints are in wide usage in the electrical industry.
6 - Question
Friction welded components are cheaper than casted components.
Explanation: Friction welded components are comparatively cheaper than casted components. Friction welded assemblies are often used to replace expensive casted and forged components
7 - Question
Which of the following components from agricultural equipment is not friction welded?
a) Track rollers
Explanation: Following are the few components which are friction welded by manufacturers of agricultural equipment; • Hydraulic piston rods • Track rollers • Gears • Bushings • Axles Cultivators are heavy duty machines used for soil cultivation.
8 - Question
Aluminium is difficult to friction weld because of _____
c) micro porosity
d) heat reflectivity
Explanation: The basic problems with friction welding of aluminium and its alloys are that they possess: • Cast brittle dendritic structure • Micro porosity • Loss of strength in heat affected zone • Solidification and liquation cracking • Fatigue properties.
9 - Question
Which of the following processes can be used as alternative technique for joining aluminium and its alloys?
a) Tungsten inert-gas welding
b) Metal inert-gas welding
c) Friction stir welding
d) Oxy-Acetylene flame technique
Explanation: The following alternate techniques are being used for joining of aluminium and its alloys: • Electron beam welding • Laser beam welding • Variable polarity plasma arc welding • Friction stir welding.
10 - Question
Which of the following is not true about friction stir welding?
a) It is a solid state process
b) Fine grained structures can be obtained
c) It eliminates friction welding problems
d) It alters the chemical composition of the workpiece
Explanation: Following are the advantages of friction stir welding: • It is a solid state process • Fine grained, re-crystallized microstructures can be obtained • It eliminates friction welding problems • There is no significant alteration of chemical composition • Routinely used to join difficult to friction weld alloys.