Binderless nano-polycrystalline diamond (NPCD) as cutting material for precision machining cemented carbide

无粘结剂纳米多晶金刚石（NPCD）作为精密加工硬质合金的切削材料

• 批准号: 446389511
• 负责人: Professor Dr.-Ing. Eckart Uhlmann
• 金额: --
• 依托单位: Fachgebiet Werkzeugmaschinen und Fertigungstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/446389511?language=en
• 关键词: Binderless; nano; polycrystalline; diamond; NPCD

Due to the hardness and strength properties as well as the good wear behaviour is tungsten carbide industrially used for punching moulds, injection moulds and cutting tools. Tungsten carbide belongs to the group of hard-brittle materials and is mainly manufactured with undefined cutting edges by grinding processes. The machining with turning- and milling processes is difficult but enables an effective manufacturing and increased geometry complexity. A limiting factor during the manufacturing with geometrical defined cutting edges is increased tool wear.In this investigation a new cutting material nano polycrystalline diamond (NPCD) is used for the cutting of cemented carbide (WC-Co). Due to the material structure NPCD achieves a hardness H comparable to single-crystalline diamond (SCD) without sharing their disadvantages such as anisotropy. In consequence of the diamond particles with particle diameter in a range of 10 nm ≤ dk ≤ 50 nm as well as the absent binder NPCD has an improved wear behaviour and promises a more efficient machining of hard to cut materials.In order to be able to use this cutting material for specific machining of cemented carbide basic knowledge about the cutting behaviour of cemented carbide, the process behaviour of NPCD during the ultra-precision turning and ultra-precision milling process, as well as their interactions needs to be acquired. Therefore, profound knowledge about the wear mechanisms and process variables, such as the surface roughness values resulting from the process and the process forces Fpr, will be acquired. Furthermore, finite element simulations for description of the mechanical interactions between the tool and the workpiece will be developed. In a first funding period about 24 month the basic knowledge with the turning process and the process simulation will be achieved. In the second funding period, which is also calculated about 24 month, the knowledge is transferred on the milling process and at the end fundamental applications for the ultra-precision turning and ultra-precision milling process with NPCD will be defined.

由于碳化钨的硬度和强度性能以及良好的耐磨性，碳化钨在工业上被用于冲压模具、注射模具和刀具。碳化钨属于硬脆性材料，主要通过磨削加工制造出具有不确定刃口的刀具。车削和铣削加工是困难的，但可以有效地制造和增加几何复杂性。利用纳米聚晶金刚石(NPCD)加工硬质合金(WC-Co)时，刀具磨损量增加是制造几何形状刀具时的一个限制因素。由于材料结构的原因，NPCD获得了与单晶金刚石(SCD)相当的硬度H，但没有共享它们的缺点，如各向异性。由于金刚石颗粒的直径在10 nm≤DK≤50 nm范围内，并且没有粘结剂，NPCD具有改善的磨损性能，并有望更有效地加工难切削材料。为了能够使用这种刀具材料进行硬质合金的特定加工，需要了解硬质合金的切削行为、NPCD在超精密车削和超精密铣削过程中的工艺行为以及它们之间的相互作用。因此，将获得关于磨损机理和工艺变量的深刻知识，例如由工艺产生的表面粗糙度和工艺作用力fpr。此外，还将开发用于描述刀具与工件之间的机械相互作用的有限元模拟。在大约24个月的第一个资助期内，将获得车削过程和过程模拟的基本知识。在第二个资金期，也是计算约24个月，传授关于铣削过程的知识，最后将定义具有NPCD的超精密车削和超精密铣削过程的基本应用。