【作者】 闫建峰；

【导师】 邓建新；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 ZrN具有硬度高、熔点高、热稳定性好、耐磨性好等许多刀具材料所应具备的特点,把其应用于刀具涂层,前景广阔。本文以课题组研制的具有高硬度和高膜基结合强度的ZrN系列涂层刀具(DZ、GZZ、FZT)为研究对象,对其切削性能、加工过程、磨损性能及机理进行系统的研究。对ZrN系列涂层刀具的切削性能进行了试验研究,并与无涂层的YT15刀具和CN25涂层刀具进行对比。试验结果表明:在相同切削条件下加工45#钢和40Cr钢时,ZrN系列涂层刀具的切削力、切削温度均明显低于无涂层的YT15刀具,而工件表面粗糙度相差较小;其中GZZ涂层刀具的切削力、切削温度最小,其切削性能最好。利用有限元方法(FEM)对ZrN涂层刀具的切削过程进行建模和仿真,研究了其切削力、温度场、应力场及与切削速度的关系。研究表明:ZrN涂层刀具切削力小于YT15刀具;切削初始阶段,ZrN涂层刀具的温度低于YT15刀具,若切削时间延长,ZrN涂层刀具的基体温度可能会等于或超过YT15刀具温度,涂层刀具在高速断续切削中涂层热障作用明显;ZrN涂层刀具和无涂层的YT15刀具的应力变化趋势基本类似,涂层刀具应力略低于YT15刀具,各涂层应力相差较小。对ZrN系列涂层刀具的磨损性能及机理进行了试验研究和理论分析,并与无涂层的YT15刀具和CN25涂层刀具进行对比。结果表明:加工45#钢时,刀具后刀面磨损量由大到小顺序为YT15＞FZT＞DZ＞GZZ;加工40Cr钢时,ZrN涂层刀具后刀面磨损量较CN25涂层刀具稍小。ZrN涂层刀具前刀面的主要磨损形式为粘结磨损和涂层剥落,后刀面的主要磨损形式为磨料磨损,三种磨损形式可能会同时发生,并相互影响。更多还原

【Abstract】 ZrN is a sort of material with very good performance.It has high hardness,high melting point,very good stabilization and high wear resistance.If we make use of it as tool coated material,it will have a good development.In the article,the research object is ZrN coated tools(DZ,GZZ,FZT).The cutting performance,wear properties and mechanisms,cutting process of the ZrN coated tools were detailed studied.The cutting performance of ZrN coated tools was studied,and compared with YT15 cemented carbide and CN25 coated tool.The results indicate that the cutting force and temperature of coated tools were all smaller than those of YT15 uncoated tools in dry machining of 45# and 40Cr hardened steel with the same condition.The workpiece surface roughness had small difference.The GZZ coated tool had the smallest cutting forces and temperature.The GZZ coated tool has the best cutting performance.The cutting process and the cutting model of ZrN coated tools were established by finite element method(FEM).The influences of cutting speed on cutting force, cutting temperature field,stress field were studied.The resarch indicate that the cutting forces of coated tools were smaller than that of YT15 uncoated tools.In the initial stage of the cutting process,the cutting temperature of the coated tools was smaller than that of YT15 tools.But the the cutting temperature of the substrate maybe equals to that of YT15 tool or even higher.The thermal barrier effect of coated tool was evident in the intermittent high-speed cutting.All the tool stress had the similar changes trend and the stress of the coated tool very smaller than that of YT15 tool.The thickness had small difference on the stress of the coatings.The wear properties and mechanisms of ZrN coated tools were studied by experiment and theoretic.In addition,the wear properties and mechanisms of ZrN coated tools were compared with YT15 cemented carbide and CN25 coated tool.The results indicate that the rate of flank wear in descending order is YT15＞FZT＞DZ＞GZZ when cutting 45# hardened steel.The GZZ’s flank wear is smaller than that of CN25 during the process of cutting 40Cr hardened steel.Different modes of tool failure including abrasive wear,adhesive wear and coating breakage were observed when machining in this study.Among these wear patterns,abrasive wear was found to be the main mode of flank wear,while adhesive wear was the main rake face wear type.It is common that several tool wear patterns may appear simultaneously at the same time and have an effect on each other.更多还原