Chapter 18 Flashcards Preview

introduction to Manufacturing Processes > Chapter 18 > Flashcards

Flashcards in Chapter 18 Deck (17):
1

3 benefits of abrasive proc.

all materials
fine surface finishes
close tolerance

2

abrasive material prop (4)

Two types.

high hardness
wear resistance
toughness
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

3

grain size for hard and soft work. scale.

hard - smaller
soft - larger
8 coarse to 250 fine

4

bonding material prop (3)

withstand high centrifugal forces.
high temp.
resist shattering during shock loading.
hold abrasive grains rigidly.

5

Wheel structure. explain.

volumetric prop.
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

6

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.

7

Explain A-46-H-6-V

abrasive type
grit size
grade
structure
bond material

8

grinding prop to get surf finish (3)

small grain
higher wheel speeds
denser wheel structure

9

3 type of grain action

cutting: material removed

plowing: surface deformed and energy consumed.

Rubbing: rubbing friction. consume energy.

10

temp damages from grinding (4)

surface burn and cracks
metallurgical damage
softening of work surf
residual stresses

11

causes of wheel wear (3)

grain fracture: friability

attritious wear - dulling grains.

bond fracture: grains pulled out. dull grain leads to this.

12

explain grinding ratio

GR = Vw / Vg
Vw volume of work material removed
Vg volume of grinding wheel worn

13

Truing vs dressing

truing return disk shape and sharpens. light depth. diamond pointed tool.

dressing only sharpens.

14

four type of surface grinding

horiz spindle. reciprocate worktable
horiz spindle with rotating worktable
vertical spindle with reciprocate worktable
vertical spindle with rotating worktable

15

what is honing

finishing bores
fine grit sizes. great finish.
corrects holes.

16

lapping. what. how. on what.

fluid with abrasives.
fine grits.
lenses, bearings, surfaces, gages.

17

superfinishing. (4)

use abrasive stick against surface and reciprocating motion.

shorter strokes
higher frequency
lower pressure b/w tool and surf
smaller grit sizes.