Development of whisker reinforced alumina ceramic tool for high speed machining of Ni-based super alloy

研制了用于高速切削镍基高温合金的TiC晶须增强氧化铝陶瓷刀具。得到的结果如下：1。新形成的TiC晶须平均直径在1微米左右。与其他体积含量的晶须相比，热压烧结（2023K,50MPa）晶须含量为30% ~ 40%的氧化铝陶瓷具有最大的断裂韧性。新开发的陶瓷刀具的维氏硬度约为2000，三点抗弯强度为920mpa，三点抗弯强度为5.3Mpa。M1/2断裂韧性。这些数值均高于市售的氧化铝陶瓷刀具。新型陶瓷刀具在切削普通碳素钢S45C时，具有比传统黑色型陶瓷刀具更高的断裂韧性。然而，新刀具的耐磨性比黑色刀具低。在加工inconel 7 - 18时，新刀具的切削性能与黑色刀具的切削性能基本相同，这意味着新刀具的切削性能低于SiC晶须增强氧化铝陶瓷刀具。在此阶段，新开发的TiC晶须增强氧化铝陶瓷刀具在切削ni基高温合金inconel 718时的切削性能与传统黑色陶瓷刀具基本相同。然而，有可能通过改变成分来改善刀具的切削性能。

TiC whisker reinforced alumina ceramic tool was developed to machine Ni-based super alloy with high cutting speed. The results obtained are as follows ;1. Mean diameter of TiC whisker which are newly developed ia around 1 micro-meters.2. Alumina ceramics with 30 to 40% of TiC whiskers sintered by hot-pressing (2023K,50MPa) showed maximum fracture toughness compare to other volume content of the whisker.3. The newly development ceramic tool have about 2000 of Vicker's hardness, 920 Mpa of 3-point bending strength and 5.3Mpa.m1/2 off racture toughness. All these value are higher than those of commercially available alumina ceramic tools.4. The new ceramic tool shows higher fracture toughness than conventional black type ceramic tool in turning of Plain carbon steel S45C.However the new tool have lower wear resistance than the black one. In machining lnconel 7 18, cutting performance of the new tool is almost same as that of the black one, that means the new tool have less cutting performance than SiC whisker reinforced alumina ceramic tool.At this stage, the cutting performance of the newly developed TiC whisker reinforced alumina ceramic tool is almost same as a conventional type black ceramic tool when cutting Ni-based super alloy lnconel 718. However, there is a possibility to improve cutting performance of the tool by changing the composition.