Study Guide P: Abrasives(Tumblers) Flashcards
What is the other name for ABRASIVE CUTTING?
GRINDING
What is used instead of metal blades in ABRASIVE CUTTTING?
GRIT
Since grains vary in size and frim course to very fine what does GRIT number mean?
Large numbers refer to fine grain and vice versa and the size of the mesh used
How is an ingot of a cermaic material made?
Created in an electrical furnace, crushed and sorted by passing fragments through mesh screens
What are typical ceramic materials used for abrasive cutting?
SILICONE, CERAMICA, ZIRCONIA, and ALUMINUM OXIDE
What are other expensive alternatives of abrasive cutting ceramics?
CBN (CUBIC BORON NITRIDE) & DIAMOND
Name the main resons to use ABRASIVE CUTTING rather than traditional machining
Cutting hardened materials, Achieve tight tolerances, and Creating superior surface finish
What are the different shapes of ABRASIVE GRITS?
WHEEL(circular shape) , CUPS (bowl shaped), MOUNTED (metal shaft), and STONES (rectangular forms)
Describe the process of AABRASIVE CUTTING.
Its the wearing down of surface through high friction and if done with a GRINDING WHEEL the GRIT with its irregulat faceted shape it will always produce chips
As the CERAMIC GRIT progressivly gets smaller in diamter as broken GRIT is shed the name of the process?
ATTRITIOUS WEAR
What are the 3 types of fractures when ABRASIVE CUTTING?
Micro fracture, Grain fracture, abd Bond fracture
Becuase of ATRICOUS WEAR the grit paricles are smoothed off overtime basically making it …
SELF SHARPENING
What is an IMPORTANT NOTE when doing GRINDING?
YOU MIUST DO THEM ON DEDICATED MACHINES, NEVER ON A LATHE OR MILL, the serious issue being if the grit gets into the ways of the machine
When designing the layout of a machine shop what is JOB ONE?
Put the GRINDING MACHINES to one side away from other machines
What must be needed to form a GRINDING WHEEL?
A BOUNDING AGENT
What are the different trypes of BONDING AGENTS?
VITRIFIED (FELDSPAR and CLAY), RESINOID (PHENOLIC or POLYIMIDE), and RUBBER
What type of grinding wheel can be used that is suituble for dedicated machine tools?
VITRIFIED wheels, since these wheels are dimensially stabe and are resistant to oils, acids and water but respond poorly to mechanical or thermal shock
What type of GRINDING WHEEL is good for POWER TOOLS?
RESINOID “Thermosetting Resin”, since the wheels are more flexible than vitrified and are more resistant to shock. They also are reinforced with a mesh of glass fiber to hold larger chucks should breakage occur
What is the common power tool that uses a RESINOID WHEEL?
ANGLE GRINDER
What type of GRINDING WHEEL is used for THIN CUT-OFF wheels?
RUBBER, and these wheels only act as a saw and are not capable of precision work, or prolonged usage but good for countouring situations such as smoothing body filler
What is used to classify GRIDNING WHEELS that is defined in the ANSI standard?
WHEEL CLASSIFICATION CODE, and goes left to right as ABRASIVE TYPE - GRAIN SIZE - GRADE - STRUCTURE - VITRIFIED BOND
What are the other interactions between a GRIT PARTICLE and workpiece?
Cuting by an individual grain, Ploughing by an individual grain, and Rubbing by an individual grain