新型陶瓷刚玉磨料制备及其性能研究

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1、中文摘要本实验利用溶胶．凝胶法制备了陶瓷刚玉磨料前驱体，并采用无压烧结技术最终制备出了新型陶瓷刚玉磨料。利用扫描电镜、金刚石单颗粒抗压强度测定仪和显微硬度测试仪等测试设备，系统的研究了不同种类添加剂、添加剂配比及加入量、造粒方式、烧结工艺对磨料的显微结构、单颗粒抗压强度和显微硬度的影响。实验结果表明，不同添加剂种类、添加剂配比及加入量、造粒方式、升温速率、烧结温度、保温时间对磨料的性能均有很大的影响。选取合适的添加剂成分能有效地控制晶粒的大小和晶型；适当的添加剂配比不但可以有效地促进氧化铝烧结，抑止晶粒的长大，同时可以提高磨料的单颗粒抗压强度；加入适量的添

2、加剂能够细化晶粒，提高磨料的强度及显微硬度；使用干凝胶直接造粒的方法得到的坯体密度较高，能显著地提高烧结体的致密度及抗压强度；烧结过程中低温阶段较高的升温速率会导致磨料颗粒出现宏观裂纹，高温阶段升温过慢会促进晶粒生长，使磨料性能恶化；烧结温度对磨料的性能影响较为明显，烧结温度过高会直接导致晶粒的长大及强度的降低；在所研究的保温时间范围内保温时间对磨料的显微结构影响不明显，但适当的保温时间却有利于提高磨料的单颗粒抗压强度。关键词：陶瓷刚玉，磨料，制备，性能ABSTRACTNewceramiccorundumabrasiveswerepreparedthrou

3、ghpressurelesssintermgoftheprecursormadebysol—gelmethod．Theeffectsofdifferentadditives，additivesconlbinationandamounts，granulationmethodsandsinteringprocessonthemicrostructure，singleparticlecompressivestrengthandmicrohardnessoftheabrasiveswereanalyzedsystematicallybyusingSEM，diamo

4、ndsingleparticlecompressivestrengthtesterandmicrohardnesstester．Theresultsshowedthatthepropertiesoftheabrasiveswereinfluencedintenselybyadditivescombinationandamounts，granulationmethods，heatingrates，sinteringtemperature，holdingtimeinthesinteringtemperature．Thegrainsizeandshapecoul

5、dbewellcontrolledbychoosingsuitableadditives．Properadditivescombinationwouldpromotesinteringofalumina，restrainthegrowthofgrains，improvethesingleparticlecompressivestrength．Withappropriateadditivesamounts，thegrainsizewasreduced．thestrengthandmicrohardnessoftheabrasiveswereimproved．

6、DirectgranulationmethodfromdrygelWasgoodtoincreasethedensityofgreenbodiesandthestrengthofsinteredbodies．Higherheatingrateinlowtemperatureperiodwouldleadtomacrocracks。whilemuchlowerheatingrateinhightemperatureperiodwouldresultintheovergrowthofabrasivegrains，whichwoulddeterioratethe

7、propertiesofabrasives．SinteringtemperaturehadobviouseffectOilthepropertiesoftheabrasive，highersinteringtemperaturewouldinducethegrowthofthegrainanddecreasethesIrengthofabrasives．HoldingtimeintheresearchedrangehadlittleinfluenceontheInicrostructureofabrasives，butproperholdingtimewo

8、uldimprovethesingleparticlestreng