Chap 31-32 remaining

Question 1

General term used to describe undesirable compounds of oxides that can form on a workpiece’s surface during welding

Answer 1

slag

Question 2

Solid state welding process in which the two surfaces to be joined are subjected to a static normal force and an oscillating shearing (tangential) force; the shearing forces are applied by the tip of a transducer and the frequency of oscillation usually ranges from 10 to 75 kHz

Answer 2

ultrasonic welding

Question 3

Solid state welding process in which the heat required for welding is generated through friction at the interface of the two surfaces to be joined; typically one workpiece remains motionless and the other is placed in a collet or chuck and rotated at a high constant speed; the two parts to be joined are then brought together by pushing their ends together;-the part that rotates must have rotational symmetry; flash is usually formed in the region of the weld and can easily be removed by machining or grinding

Answer 3

friction welding

Question 4

Solid state welding process in which a third body often a rotating non-consumable probe that is rubbed against the two surfaces to be joined; the contact pressure causes frictional heating up to 230 to 260 degrees Celsius and the probe at the tip of the rotating tool forces mixing of the material at the joint; no shielding gas or surface cleaning is required

Answer 4

friction stir welding

Question 5

Welding process in which the tops of two opposing solid, cylindrical electrodes touch a lap joint of two sheet metals, and resistance heating produces a spot weld; it is the simplest and most commonly used resistance welding process

Answer 5

resistance spot welding

Question 6

A joining process in which filler material (usually a metal) is placed between the surfaces to be joined and the temperature is raised sufficiently to melt the filler material but not the parts being joined; it takes place above 450 degrees Celsius and produces stronger joints than soldering; it is good for joining dissimilar metals and for intricate, lightweight parts, fragile parts, parts with very different characteristics (sizes, thicknesses, cross-sections) and parts that cannot withstand a high temperature; a flux should be used to prevent oxidation and remove oxide films

Answer 6

brazing

Question 7

A joining process similar to brazing but with lower temperatures and lower joint strength; as In brazing, the filler metal fills the joint by capillary action between closely fitting or closely placed components and a flux is used to reduce oxidation; the filler metal melts at a lower temperature; it is widely used in the electronics industry

Answer 7

soldering

Question 8

The use of glue (either animal-derived or synthetic) or other intermediate material in the form of a liquid, paste, solution, emulsion, powder, tape or film—often at room temperature–to join two parts; it has a wide application in consumer and industrial products and in the aerospace industry; it dates back to 3500 BC; very little weight is added to the parts that are combined but the bonding time can be long

Answer 8

adhesive bonding

Question 9

Solid state welding process in which two parts are joined via pressure that is generated by detonating a layer of explosive that has been placed over one of the components being joined; it is useful for joining a plate or slab with a dissimilar metal

Answer 9

explosion welding

Question 10

Pressure applied to the work pieces through dies or rolls, plastic deformation involved, one of the mating parts be sufficiently ductile, surface preparation is important for adequate bonding

Answer 10

friction welding