Flashcards in Chapter 18 Deck (17):
3 benefits of abrasive proc.
fine surface finishes
abrasive material prop (4)
friability ( new sharp edge after fracture dull edge)
alumina: ferrous high strength alloy and steel
SiC: harder than alumina not as tough. Aluminum, brass, SS, cast iron
cBN: steel. Hardened tool steel.
Diamond: not for grinding wheel. ceramics, cemented carbides, and glass
grain size for hard and soft work. scale.
hard - smaller
soft - larger
8 coarse to 250 fine
bonding material prop (3)
withstand high centrifugal forces.
resist shattering during shock loading.
hold abrasive grains rigidly.
Wheel structure. explain.
Pg 50%. abrasive part.
Pb 10. bond part.
Pp 40. pore part.
1 - very dense.Pp small Pb large
15 - very open. Pp large Pb small
wheel grade. what used for.
depend on bonding particles.
soft - lose grains. low material rem rates and hard work. A grade
hard - high stock rem rates and soft materials. Z grade.
grinding prop to get surf finish (3)
higher wheel speeds
denser wheel structure
3 type of grain action
cutting: material removed
plowing: surface deformed and energy consumed.
Rubbing: rubbing friction. consume energy.
temp damages from grinding (4)
surface burn and cracks
softening of work surf
causes of wheel wear (3)
grain fracture: friability
attritious wear - dulling grains.
bond fracture: grains pulled out. dull grain leads to this.
explain grinding ratio
GR = Vw / Vg
Vw volume of work material removed
Vg volume of grinding wheel worn
Truing vs dressing
truing return disk shape and sharpens. light depth. diamond pointed tool.
dressing only sharpens.
four type of surface grinding
horiz spindle. reciprocate worktable
horiz spindle with rotating worktable
vertical spindle with reciprocate worktable
vertical spindle with rotating worktable
what is honing
fine grit sizes. great finish.
lapping. what. how. on what.
fluid with abrasives.
lenses, bearings, surfaces, gages.