数控立方氮化硼刀具的使用选择

介招立方氮化硼（PCBN）材料的性能特点和CBN对聚晶立方硼（PCBN）刀具的性能影响，通过对PCBN刀具的几何参数和切削用量的选择，充分利用其材料的性能，在实际工作中取得较好效果。     

Evaluation of machining performance of STAVAX with PCBN tools

A study was undertaken to investigate the wear characteristics of polycrystalline cubic boron nitride (PCBN) cutting tools and surface integrity during machining of STAVAX (specialised stainless steel) with and without coolant. Plastic deformation and formation of overtempered martensite and white layer (untempered martensite) were the dominant subsurface and surface defects. It was found that decreasing the hardness of the STAVAX from 55 HRC to 40 HRC could result in fracture on the flank face, leading to a deterioration of the surface finish. It was observed that low CBN content tools (60%CBN/40%TiN) exhibited greater fracture resistance than high CBN content tools (85%CBN/15%TiN, 90%CBN/10%Co). Although coolant could not bring about a reduction in the flank wear, it was effective in reducing the subsurface and surface defects, and in preventing chipping of the tool edge, leading to an improved surface finish. A superior surface finish (Ra<0.3 m) was obtained with cutting fluid using a tool with a radius of 0.8 mm, depth of cut of 0.05 mm and feed rate of 0.05 mm/rev.     

PCBN刀具切削堆焊钴基合金的试验研究

采用PCBN刀具对堆焊钴基高温合金层进行切削试验,研究不同的切削用量和刀尖圆弧半径对表面粗糙度和切削力的影响规律,并采用离差分析法对其影响程度进行评估。试验结果及分析表明:切削加工堆焊钴基合金时,切削力和表面粗糙度的部分变化规律有别于传统切削理论,这是因为钴基堆焊合金特有的物理机械性能、堆焊层组织状态、PCBN刀具的性能特点及所选取的几何参数使切削区域材料性能变化和刀具磨损特征不同于传统切削理论所致。试验获得的表面粗糙度值较小,符合以车代磨的加工工艺要求。由离差分析结果可知,进给量对表面粗糙度、主切削力和背向力影响最大,背吃刀量对进给力的影响最大。     

PCBN刀具切削GCr15淬硬轴承钢时刀具磨损的研究

通过切削实验，研究了PCBN刀具切削淬硬轴承钢时刀具磨损形态及磨损机理。实验表明。PCBN刀具前刀面的磨损为月牙洼磨授，后刀面的磨损为机械磨损，其磨损程度与工件硬度呈非线性关系，并随着切削速度的提高磨损量减少。     

PCBN刀具干湿切削淬硬钢表面完整性研究

本文以采用PCBN刀具切削淬硬轴承钢GCr15为试验，对干、湿切削两种润滑条件下，工件表面粗糙度及表面白层（一种在加工表面形成的晶相组织发生变化的结构）进行了对比研究。实验结果表明：干、湿切削都可获得较好的表面粗糙度，湿切削表面粗糙度Ra稍低；湿切削没有发现明显的白层产生，干切削白层生成较早，且白层与黑层的厚度随着刀具磨损的增加而逐渐增加。     

Influence of grinding parameters on the quality of high content PCBN cutting inserts

Plunge-face grinding is commonly used to finish PCBN cutting inserts. In order to reach an adequate process design, an investigation of the influence of the grinding parameters on the quality of high content PCBN inserts is carried out in this work. For this, the inserts are ground with different grinding wheels (including a variation of grain size and bonding), dressing feed rates, feed and cutting speeds and the edge chipping and flank face roughness are measured. It was found that a reduction of the abrasive grain size as well as an increase of the dressing feed rate lead to an improvement of the insert edge and surface quality. Moreover, a variation of the cutting and feed speeds has only a small influence on the PCBN insert quality.     

PCBN磨粒／石墨／CuSnTi合金复合块界面微观结构

在加热温度920℃和保温时间30min工艺下,进行铜锡钛（Cu-Sn-Ti）合金与石墨颗粒、聚晶立方氮化硼（PCBN）磨粒的烧结试验．通过三点抗弯试验测试了烧结试样的强度,并使用扫描电镜、能谱仪、x射线衍射仪检测了复合块的断口形貌与物相组成．结果表明,石墨质量分数为5％～15％时烧结试样的抗弯强度达91MPa以上,高于...     

PCBN刀具干车淬硬钢时倒棱前角对切削力和刀具磨损的影响

PCBN刀具磨出负倒棱是为了加强刀具的刃口强度，以减少刀具加工时可能出现的破损情况。本文通过对PCBN刀具加工淬硬轴承钢GCr15的一系列试验数据加以分析，得出倒棱前角和切削力、刀具磨损之间的关系，进而得出在实际加工情况下应该采用的最佳倒棱前角值。试验表明：当倒棱前角取15度且切削速度为125m／s时，刀具具有最好的加工效果，不但切削力可以达到最小值，刀具磨损最轻，而且刀具寿命也达到了最大值。     

PCBN tool wear modes and mechanisms in finish hard turning

The use of polycrystalline cubic boron nitride (PCBN) cutting tools in hard turning applications is continuously growing with the number of commercially available grades increasing, allowing new application areas to be explored. In order to take full advantage of the benefits offered by PCBN it is necessary to understand the behaviour of the material in application. Tool behaviour is influenced by many factors which include the composition of the PCBN material, the steel workpiece, the nature of the cutting operation, the cutting conditions and the tool geometry.

The focus of this paper is the continuous turning of hardened steels. A significant amount of research has been carried out in this area and a literature review of the relevant work is presented. This identifies the primary wear modes and discusses the many theories proposed to explain the mechanisms contributing to PCBN tool wear and failure. The final section of the paper considers the critical factors that influence the behaviour of PCBN tools in continuous hard turning and how this knowledge can be applied to optimise tool performance.     

直径为33毫米PCBN的合成及性能研究

研究了直径达33mm立方氮化硼复合体(PCBN)的合成技术,并采用所研制的定点压力补偿和局部温度补偿技术,改善了压力梯度和温度梯度.开发出了最大片径达33mm,耐磨性达1:6 000以上,耐热性达1 150℃,CBN层抗弯强度达700MPa,维氏硬度3 000HV的PCBN材料.