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1、2.ABriefHistoryofAbrasiveTechnologyItisdifficulttosaywhenabrasivetechnologyhadabeginning.Abrasivewereusedbymanmanythousandsofyearsbeforehelearnedtowrite・Primitivemanusedabrasivesforthesharpeningoftoolsofwood,boneorflint.Laterintheperiodprecedingtheinventionofpotteryabrasiveswereuse
2、dforgrindingoutstonestomakebowlsanddishes.Abrasiveswere,andstillarc,usedbyotherformsoflife,bybirdsforthesharpeningofbeaks,andbysomespeciesofantleredanimalsfortheshaipeningoftheirhorns.Thebeginningofthescienceofabrasives,however,maybetakenasthattimewhenmanbegantoselectcertainrocksfo
3、rtheirpeculiarproperties,andtofashiontheseintotoolsforgrinding.TheearliestrecordofsuchactivitycomestousfromEgypt.Evidencecollectedthereindicatesthatstoneswerebeingsawedbysomecrudesortofgrindingmacliineasearlyas4000B.C.Therealblossomingoftheabrasiveindustrycoincidedwiththebeginnings
4、ofmetallurgywhichtookplaceinthenearandmiddleeastabout2000B.C.Abrasivesthenbecameanecessityoflifeandtheirdevelopmenthaskeptpacewiththedemandsofmetallurgyfromthatlimeuntil(hepresentday.TheearliestrecordoftheuseofabrasivesforthegrindingofmetalalsocomestousfromEgypt.Asteeldaggerwasfoun
5、dtherealongwithasharpeningstone,whichhasbeendatedatabout1500B.C.Duringthefollowingcenturiesthetechniquewasdevelopedforfashioninggrindingwheelsfromnaturalsandstones・Thesewereturnedbyhandatfirst,butbythe14lhcenturywaterwheelswerebeingused.Theseearlysandstoneswerenotunlikethosestillin
6、use.Fromtheseearlybeginningsthemodemabrasiveindustrygraduallyevolved.Thedatesofthegiantstepstowardthepresentstateoftheartareoftenquiteobscure,asarethenamesoftheindividualsresponsibleforthem.Inwhatfollows,inordertoputthisindustryinperspective,itisattemptedtolistthemajoradvancesinchr
7、onologicalorder,andtogivecredit,whereverpossible,totheinnovators.Indoingthisthreeseparatecategorieshavebeentreatedindividually.Theseare:theabrasives,thebondedabrasiveproducts,andthemachinesusingabrasiveproducts.Thelattercategoryisincludedbecauseitisthis,morethananythingelse,thathas
8、propelledthegrowthoftheind
