【作者】 林峰；

【导师】 吕海波；

【作者基本信息】 中南大学 ， 材料学， 2009， 博士

【摘要】 本文简述了金刚石复合片（简称PDC）国内外发展概况,针对国内刀具用PDC的技术发展现状及存在的不足,在工业生产条件下利用正交试验方法进行了PDC合成工艺的优化及验证,借助扫描电镜、能谱、X衍射、激光拉曼光谱等先进检测手段,分析与研究了本研究产品的主要性能,旨在开发出高性能刀具用金刚石复合片。本研究开展了以下工作:（1）进行了合成腔体内的压力标定、温度标定,使用有限元分析方法模拟分析了合成腔体内的温度分布;研究了叶腊石块的失重率、抗压强度、剪切强度随着焙烧温度的变化规律及叶腊石的焙烧工艺;利用正交试验方法进行了PDC合成工艺的优化及验证。（2）采用混合烧结和渗透烧结相结合的方法合成刀具用PDC,分析了其烧结的热力学、动力学特征,并指出:在金刚石微粉层中添加了合成温度下可熔融并对金刚石颗粒表面侵润的金属的方法应是加速PDC烧结和组织均匀化过程的有效方法。（3）研究了在不同合成条件下所合成的PDC的耐磨性、显微硬度、抗弯强度的变化规律及径向耐磨性的分布特征,指出了合成工艺的控制和调整原则。（4）从原材料选择和层间结合强度方面研究了PDC的耐热性能,优选出可明显提高PDC耐热性能及成品率的工艺方法。（5）使用本研究合成的PDC制作的刀具进行了切削铝合金的试验,研究了切削参量对切削力及被加工工件表面粗糙度的影响规律、性能变化特征,研究了实验刀具切削高硅铝合金的磨损形态、特征,分析、探讨了其磨损机理;同时分析研究了切屑特征和被加工工件材料的切除机理;最后研究对比了本研究合成的PDC与韩国PDC产品的切削使用效果。本研究取得了以下创新成果:（1）利用有限元分析结果优选合成块端片材料,实现合成腔体的温度补偿,有效避免了腔体扩大后温度分布剃度过大的弊端,减少了PDC边缘和中心的温度差,使PDC的烧结更均匀。（2）首次提出以混合烧结和渗透烧结相结合的方法合成PDC,指出在金刚石微粉层中添加在PDC合成温度下可熔融并对金刚石颗粒表面侵润的金属的方法应是加速PDC烧结和组织均匀化过程的有效方法。（3）首次以超硬材料混合料（CBN+Al+Co）作为PDC的过渡层材料,既提高了PDC的耐热性和成品率,同时有效抑制了PDC脱层、碎裂现象的产生。采用镀钛金刚石微粉（平均粒度5微米）合成PDC,其耐热性能约提高了200℃左右。（4）利用测试结果回归分析了合成腔体中的温度与加热电流存在的对应关系:Y=1.1553^1.799,并指出合成腔体的加热主要是由焦耳效应形成热量。（5）通过切削较高Si含量铝合金的方法,快速查明PDC刀具切削硅铝合金时的磨损特性及规律。（6）在工业生产条件下进行PDC的研究开发,成果不需中试可直接进入产业化阶段。项目所研制的PDC与韩国日进的PDC使用寿命相当,项目产品已达到韩国产品的质量水平。更多还原

【Abstract】 A general introduction on research and development(R&D) of polycrystalline diamond compacts(PDC) is given in this thesis.R&D for PDC materials applied for cutting tools needs to be further enhanced in our county.In this work,the PDC sintering processes is optimized using orthogonal experiments.Meanwhile the sintered PDC samples are studied by various methods such as SEM,EDS,XRD,Raman,etc.With the optimized experimental conditions,we have prepared the high quality PDC materials for cutting tools.The major work in this thesis includes the following parts:(1) The pressure and temperature of sintering cell are confirmed.The temperature distributing in the cell is simulated by ANSYS soft.The change rule of pyrophyllite weight loss,compression strength and tensile strength are investigatedat different temperatures,and pyrophyllite heat treatment process is also studied.The high-pressure and high- temperature sintering processes for PDC materials are optimized using orthogonal experiments. (2) The PDC materials for cutting tools are sintered in our work by way of mixing and infiltration sintering technique.The character of sintering thermodynamics & dynamics are analyzed.It concludes that some metal powder mixed with diamond grits,which can be melted under the sintering temperature,is helpful for wetting diamond powder with binders.So that the sintering time can be shorten and its microstructure will be more uniform.(3) The wear resistance,micro-hardness and compression strength of PDC sintered under different condition are investigated.Moreover the rule of wear ratio along PDC radial is also investigated.The control and adjustment principles of sintering process are summarized.(4) The PDC resistant-heat is studied by choosing different materials and according to united strength between polycrystalline diamond and tungsten carbide.Then a process method is made that improve its resistant-heat and eligibility ratio.(5) Some inserts are made for cutting Al-alloy with our PDC.Through the cutting experiments with different parameters,influence rule and quality variety characters are studied.The abrasion character are investigated while cutting high-silicon Al-alloy.So abrasion mechanism are analyzed and discussed.Meanwhile cutting bits character and cutting mechanism while cutting materials are also researched.Finally cutting experiment is carried out with our PDC,and compared with Korea PDC.Some innovations are made in this thesis:(1) The assembly cell is optimized by ANSYS.According to this result temperature distribution control is taken in the cell in order to decrease temperature grads owing to the enlarged cell.So the PDC temperature difference is decreased between edge and center.Therefore it will increase PDC sintering uniformity.(2) A method of mixed and infiltration sintering technique are used for PDC synthesis.It is found that the sintering time can be shorten and a even microstructure can be obtained.(3) A mixture of CBN-Al-Co is considered as a transition layer of PDC.It can improve resistant-heat and eligibility ratio of PDC.Simultaneity it can restrain delamination and chip of PDC.The resistant-temperatuare of PDC can be improved about 200℃when it is sintered with titanium coated diamond.(4) A result is made about corresponding connection of temperature and heating current in the cell by regress analysis,Y=1.1553X1.799.It is found that quanity of heat in the cell is produced by joule effect.(5) Abrasion character and rule are found quickly by cutting superhigh-Si Al-alloy.(6) PDC is researched under industry condition.And research production is applied into industrialization without examination phase.The cutting life of our sintered PDC is alike with Korea PDC,so the quality of our PDC is the same with Corea’s.更多还原