【作者】 马廉洁；

【导师】 于爱兵；

【作者基本信息】 天津大学 ， 机械制造及其自动化， 2004， 硕士

【摘要】 选择氟金云母、ZrO₂/CePO₄两种可加工陶瓷,分别进行了钻削、车削加工实验,分析了材料去除过程和刀具磨损过程。以SEM电镜研究材料去除机制和刀具磨损形态,通过单因素实验考察了工艺条件对材料去除和刀具磨损的影响。两种材料的加工去除包括穿晶断裂和沿晶断裂两种模式。ZrO₂/CePO₄陶瓷钻削时的材料去除过程可分为高效率阶段和高磨损阶段。而氟金云母陶瓷的材料去除过程可分为初期阶段、稳定阶段、后期阶段三个阶段。ZrO₂/CePO₄陶瓷钻削时,刀具磨损过程可分为初期磨损和后期磨损两个阶段。初期阶段为正常加工时段,后期阶段为快速磨损时段。加工氟金云母陶瓷时,刀具磨损过程可分为初期磨损、稳定磨损和过度磨损三个阶段。钻头磨损发生在主后刀面、第一副后刀面和横刃处,车刀磨损主要发生在主后刀面和刀尖处。磨料磨损、粘结磨损是一普遍现象。加工ZrO₂/CePO₄时钻头失效的主要原因是氧化磨损,加工氟金云母时刀具破损的型式有切削刃塑性变形、裂纹与剥离,崩刃,后刀面麻点等。材料中分布的硬质点、热导率低以及机械冲击和热冲击作用,是刀具失效的主要原因。刀具材料、冷却条件、切削用量、刀具角度等对材料去除、刀具磨损均产生一定影响,其中刀具材料、冷却条件对其影响较为显著。可加工陶瓷机械加工中,选择适当的工艺条件,可有效地降低刀具磨损,提高加工效率。更多还原

【Abstract】 Two machinable ceramics, ZrO₂/CePO₄ and fluorophlogopite, werechosen for cutting test. During turning and drilling, the process of materialremoval and tool wear were analysed. Material removal mechanism and toolwear modes were studied through SEM observations. With single-factor tests,the influences of machining conditions on material removal and tool wearwere studied.Material removals of two ceramics contain two modes, transgranularfracture and intergranular fracture. In drilling ZrO₂/CePO₄ ceramics, theprocess of material removal can be divided into high material removal rateperiod and high tool wear period. However, in cutting fluorophlogopite, theprocess of material removal can be divided to initial period, stable period andterminal period.In drilling ZrO₂/CePO₄ ceramics, the process of tool wear can be dividedinto beginning and terminal periods. The beginning is a normal period and theterminal is a quick wear period. In cutting fluorophlogopite, the process oftool wear can be divided to beginning, stable and immoderate wear period.In drilling, wear of drill bits usually occurs on major flank, minor flankand chisel edge. In the fluorophlogopite turning, wear of tools usually occurson major flank and tool corner. Abrasive wear and adhesive wear are commonphenomena. The main disrepair mode is oxidation wear in drillingZrO₂/CePO₄. However, the main rupture modes are plastic deformation ofcutting edge, flaw, scaling, fragmentation and pock on cutting edge.Distributing hard particles in fluorophlogopite, the mechanical and thermalvibrancy, and low thermal conductivity cause the invalidation of drill bits.The machining conditions affect material removal and tool wear, such astool materials, cooling condition, cutting parameter and tool angles.Especially, the tool materials and cooling conditions are the major factors.The tool material and machining parameters should be optimized toobtain low tool wear and high machining efficiency in cutting machinableceramics.更多还原