断续 CBN 砂轮缓进给磨削 K417 航空叶片材料的研究

 全面比较了用Al2O3和CBN磨削K417铸造高温合金时的磨削效果，指出：Al2O3不适于高效磨削K417之类的航空难加工材料，而CBN是实现该材料高效深切磨削的有效工具。通过大量实验，验证了断续CBN砂轮缓进给磨削K417时的技术优势，解决了树脂结合剂应用于断续磨削时所遇到的新问题。分析显示出该技术具有很好的应用前景和极大的推广价值。     

Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

For high-efficiency grinding of difficult-to-cut materials such as titanium and nickel alloys, a high porosity is expected and also a sufficient mechanical strength to satisfy the function.However, the porosity increase is a disadvantage to the mechanical strength. As a promising pore forming agent, alumina bubbles are firstly induced into the abrasive layer to fabricate porous cubic boron nitride（CBN） wheels. When the wheel porosity reaches 45%, the bending strength is still high up to 50 MPa with modified orderly pore distribution. A porous CBN wheel was fabricated with a total porosity around 30%. The grinding performance of the porous composite-bonded CBN wheel was evaluated in terms of specific force, specific grinding energy, and grinding temperature, which were better than those of the vitrified one under the same grinding conditions. Compared to the vitrified CBN wheel, clear straight cutting grooves and less chip adhesion are observed on the ground surface and there is also no extensive loading on the wheel surface after grinding.     

陶瓷CBN砂轮修锐效果的砂轮地貌评价

对磨削性能下降的陶瓷CBN砂轮进行不同程度的修锐,用激光三角法的砂轮地貌测量系统对各状态下砂轮地貌进行测量。得到了砂轮地貌的三维形貌和磨粒出刃高度、磨粒刃密度的变化特点,以此评价修锐效果。结果表明,陶瓷CBN砂轮的修锐对砂轮磨粒的出刃性、等高性和均匀性有很大改善。     

航发涡轮叶片气膜孔的磨削加工实验

针对目前航空发动机涡轮叶片气膜孔加工精度低和重熔层难去除的问题,提出了"电火花打孔、磨削扩孔"的新型气膜孔加工工艺,研制出小孔磨削专用微细CBN砂轮并对电火花气膜孔进行了磨削工艺实验。实验结果表明:经磨削加工后气膜孔圆度降低50.9%,孔径尺寸标准差降低90.7%,表面粗糙度降低65.9%,重熔层被全部去除,证明了航发涡轮叶片气膜孔磨削加工的可行性。     

金刚石和超硬材料的应用与展望

介绍了金刚石及超硬材料的发展近况和应用,并指出这些材料的发展将为促进精密加工与超精密加工领域的进步起到十分重要的作用．     

电镀立方氮化硼砂轮在超深小孔磨削中的应用

电镀立方氮化硼砂轮在高精度、低表面粗糙度值的超深小孔磨削中,可大幅提高砂轮轴刚性,从而提高加工质量和生产效率。     

精密金刚石、CBN电镀刀具内包容流动旋转植砂的研究

金刚石、CBN电镀刀具在实际中获得了一定的应用。目前，改进电镀制造工艺、提高刀具制造精度和制造效率仍然是电镀刀具制造中主要研究的问题。本文提出流动旋转植砂技术，它可以提高金刚石、CBN磨粒外包络面上的磨粒数，这样就可以保证内镀法刀具切刃的等高性、型面精度和有效磨粒数。     

杯形陶瓷CBN砂轮修整工艺及参数优化

针对金刚石滚轮修整杯形CBN砂轮时各修整工艺参数对砂轮修整后磨削TC 4时的磨削温度、磨削力和表面粗糙度的影响进行实验研究,并对磨削温度和表面粗糙度进行了多因素回归分析.在回归分析得到的数学模型基础上,进一步对磨削温度和表面粗糙度进行双目标加权优化,得到了粗磨和精磨钛合金时砂轮的最佳修整参数,并通过磨削实验对优化结果进行了验证.     

Prediction on grinding force during grinding powder metallurgy nickel-based superalloy FGH96 with electroplated CBN abrasive wheel

In this article, a grinding force model, which is on the basis of cutting process of single abrasive grains combined with the method of theoretical derivation and empirical formula by analyzing the formation mechanism of grinding force, was established. Three key factors have been taken into accounts in this model, such as the contact friction force between abrasive grains and materials, the plastic deformation of material in the process of abrasive plowing, and the shear strain effect of material during the process of cutting chips formation. The model was finally validated by the orthogonal grinding experiment of powder metallurgy nickel-based superalloy FGH96 by using the electroplated CBN abrasive wheel. Grinding force values of prediction and experiment were in good consistency. The errors of tangential grinding force and normal grinding force were 9.8% and 13.6%, respectively. The contributions of sliding force, plowing force and chip formation force were also analyzed. In addition, the tangential forces of sliding, plowing and chip formation are 14%, 19% and 11% of the normal forces on average, respectively. The pro-posed grinding force model is not only in favor of optimizing the grinding parameters and improving grinding efficiency, but also contributes to study some other grinding subjects (e.g. abrasive wheel wear, grinding heat, residual stress).     

高温耐热合金 GH169 的深小孔钻削加工性

研究了高速钢麻花钻头、硬质合金钻头和电沉积ＣＢＮ高速钢钻头钻削高温耐热合金ＧＨ１６９,其横刃部分采用“Ｓ”型的修磨结构时钻削深小孔的性能,并优化了钻头横刃的修磨等几何参数和切削参数。实验表明：采用硬质合金钻头或电沉积ＣＢＮ钻头钻削高温耐热合金ＧＨ１６９是切实可行的。而且改善了加工条件,提高了加工质量和生产效率。