Manufacturing Technology I Set 12

Answer: rotational

Explaination:
inertia friction welding is a variation of friction welding in which the energy required to make the weld is supplied primarily by the stored rotational kinetic energy of the welding machine.

Answer: flywheel

Explaination:
in inertia welding, one of the workpieces is connected to a flywheel and the other is restrained from rotating. the flywheel is accelerated to a predetermined rotational speed, storing the required energy. the drive motor is disengaged and workpieces are forced together by the friction welding force.

Answer: incomplete fusion

Explaination:
incomplete fusion defects occur when weld metal layer fails to fuse together. it causes discontinuity in weld zone.

Answer: undercut

Explaination:
undercut is the cardinal sin of welding grasshopper! cutting into the steel with the force of the arc leaves a cut out groove in the weld. if this is not filled back in with filler metal, it leaves a weld defect which is a weak point that can cause the joint to fail. this can cause property damage, injury and even loss of life.

Answer: false

Explaination:
forging is a metal forming operation in which heated metal is beaten by a hammer to give it the desired shape. it is basically a deformation process in which the material is compressed between dies by using impact load to deform it. forging can also be used for making complex shapes of metal parts.

Answer: false

Explaination:
in general, forged parts are much stronger and tougher than the casted parts made from the same metal. the metal components have high strength because the hammering operation maintains its structure that makes proper alignment of grains along the profile of metal components, which leads to an increase in strength.

Answer: true

Explaination:
in an open die forging process, the metal billet is heated up to a very high temperature and then compressed between two flat die halves. this method is like a compression test, which is also known as upsetting or upset forging. in the process, billet is basically deformed by a decrease in its height and increase in its diameter.

Answer: forging

Explaination:
connecting rods are generally manufactured by the forging operation. in forging, a hammer is used which strikes on the heated metallic part to get into the desired shape. the properties like strength, toughness, etc are greatly enhanced by performing the forging operation. forging can be open die forging or closed die forging.

Answer: true

Explaination:
in impression die forging process, flash can be produced which is considered as scrap material that is removed from the formed part during the finishing of a metal part. but in flash-less forging, the metal is fully prevented within the die, so no flash is produced during the process.

Answer: true

Explaination:
in the orbital forging process, forming is done to the meat part by using a cone-shaped die that is simultaneously rolled and pressed into the material. the metal part is supported on a lower die, because of inclined axis of cone. in the process, only a small area of the metal surface is compressed at the stage of forming.

Answer: a twist

Explaination:
when an asymmetrical section is a roll formed, the finished product will have a twist after leaving the last pass, even if the starting material is flat.

Answer: no time is lost in changing the shape

Explaination:
no time is lost in changing the shape as the dies may be readily removed in the process of extrusion.

Answer: direct

Explaination:
direction extrusion is a process in which the metal billet, placed in a container is forced by a ram to pass through a die. in this type, the direction of flow of metals is, in same as that of movement of ram. the punch closely fits the die cavity to prevent the backward flow of the material.

Answer: indirect

Explaination:
indirect extrusion method is not used because of the problem of handling extruded metal coming out through moving ram.

Answer: hydrostatic extrusion

Explaination:
cold extrusion is done at room temperature or near room temeprature. the processes, impact extrusion, hydrostatic extrusion and cold extrusion forging are the types of cold forging. the advantages of this over hot extrusion are the lack of oxidation, higher strength due to cold working, closer tolerances, and good surface finish.

Answer: all of the mentioned

Explaination:
cracks that are developed in the centre of extruded material is known as internal cracking. these are termed as “centre cracking”, “centre burst”, “chevron cracking”, and as “arrow head cracking”.

Answer: stretch forming

Explaination:
stretch forming is a sheet metal forming process in which the sheet metal is clamped at the edges and stretched by using the dies or form blocks. and no any lubrication is required significantly during the process. this method is best suited for making the products like aircraft wings, window frames, automobile door panels etc.

Answer: true

Explaination:
in stretch forming process, stretching of a metal sheet is basically done by holding its edges and bending it on a cylindrical block, simultaneously is known as stretch forming. this process basically involves tensile and bending forces during the operation. in this process, the materials with high ductility are mostly stretched by rigid dies.

Answer: false

Explaination:
forming is basically a term that covers many manufacturing processes. in the metal forming process, the shape of the material or metal is changed by performing an operation like hammering, squeezing, bending, pulling etc. without changing its phase. the raw materials used in the forming process remained in a single solid phase.

Answer: true

Explaination:
rolling is a metal forming process in which the metal plate is squeezed between the two hard rollers. in the operation, the thickness is decreased and the length is increased as the volume of the metal is conserved. this method is mainly used for the production of thin metal plates which can be done by performing hot rolling or cold rolling, depending on the required mechanical properties.

Answer: true

Explaination:
in stretch forming, a metal sheet is stretched by the help of stretcher

Answer: false

Explaination:
spring-back is basically defined as a phenomenon in which the material tries to regain its original shape during elastic loading condition. but in stretch forming process, the stretching and bending operations take place simultaneously which causes permanent deformation of the sheet metal. so, this combined effect results in negligible spring-back in the metal part and hence causes no problem in the operating machines.

Answer: stretch forming

Explaination:
stretch forming is a sheet metal forming process in which the sheet metal is clamped at the edges and stretched by using the dies or form blocks. and no any lubrication is required significantly during the process. this method is best suited for making the products like aircraft wings, window frames, automobile door panels etc.

Answer: false

Explaination:
in stretch forming, the sheet metal is fixed with stretch gripper with the support of a tool, and then operation takes place in a hydraulic stretching unit. the process consumes too much time as the stretching process takes time to strain hardens the material. so, this process includes low volume rate of production, but the process is very versatile and have economic production.

Answer: false

Explaination:
tangential stretch forming is very different from simple stretch forming. however, the purpose is same. in tangential stretch forming, the metal sheet is gripped from two opposite ends. the main difference to the simple stretch forming is that the form block and gripping jaws both are movable in this process.