ENME 421 Midterm 2- v2 exam with complete solutions.

Name and describe 4 forming operations used to shape metal alloys - forging: mechanically working or deforming a single piece of a usually hot metal; this may be accomplished by the application of successive blows or by continuous squeezing; can be closed or open die - extrusion: a bar of metal is forced through a die orifice by a compressive force that is applied to a ram; the extruded piece that emerges has the desired shape and a reduced cross-sectional area - rolling: passing a piece of metal between two rolls, results in a reduction of thickness - drawing: pulling a metal through a die having a tapered bore by means of tensile force applied on the exit side Closed die vs Open die (forging) - closed die: a force is brought to bear on two or more die halves having the finished shape such that the metal is deformed in the cavity between them - open die: two dies having simple geometric shapes are employed, normally on large workpieces Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:00 / 0:15 Full screen Brainpower Read More Which microconstituents/phases are typically found in a low-carbon steel? Ferrite and pearlite Name and describe 5 casting techniques - sand casting: two-piece mold is formed by packing sand around a pattern that has the shape of the intended casting; ordinary sand is used as the mold material - continuous casting: aka strand casting; the refined and molten metal is cast directly into a continuous strand that may have either a rectangular or circular cross section; solidification occurs in a water-cooled die having the desired cross-sectional geometry - die casting: the liquid metal is forced into a mold under pressure and at a relatively high velocity and allowed to solidify with the pressure maintained; a two-piece permanent steel mold or die is employed; when clamped together, the two pieces form the desired shap