纳米复合氮化硅刀具材料的制备与性能

以碳化硅纤维为纤维增强剂,纳米级碳化钛为粒子增强剂,氮化硅粉末为基体,制备Si_3N_4/SiC_w/TiC_p系纳米复合陶瓷刀具材料。采用XRD和SEM分别表征复合氮化硅烧结体的组成和表面微观形貌。采用三点弯曲法,用PSD-5TSJTH型万能试验机测量样品的密度和抗弯强度。对于制备的Si_3N_4/SiC_w/TiC_p系纳米复合陶瓷刀具材料进行断续切削试验和连续切削试验。结果表明,制备的Si_3N_4/SiC_w/TiC_p系纳米复合陶瓷刀具的断裂韧性最高达9.5 MPa·m0.5,抗弯强度达780 MPa,显著地超过一般氧化铝陶瓷切削刀具材料的韧性值。断续切削时刀具的寿命比氧化铝陶瓷刀具更长1.6~15倍,连续切削时也具有良好的耐磨性能。

Fabrication and Properties of Nano-Composite Silicon NitrideCuttingTool Material

The nano-composite ceramic tool material with fiber reinforcer of silicon carbide fiber, particle reinforcer of nano-titanium carbide and base metal of silicon nitride powder was fabricated.XRD and SEM analyses were used for the composite silicon nitride sintering and microstructure of the composite ceramic tool material, respectively. The density and bending strength of sample were measured by the three point bend method and the PSD-5TSJTH universal testing machine, respectively. The fracture toughness was calculated on Si₃N₄/SiC_w/TiC_pseries nano-composite ceramic tool material, the interrupted cutting test and continues cutting tests were progressed. The research showed that the fracture toughness and bending strength of fabricated MC-C tool material reached 9.5MPa.m_0.5 and 780MPa, respectively. Namely, it had more remarkable toughness than ordinary alumina ceramics. The interrupted cutting lifetimes of tool was longer 1.6~15 times than the alumina ceramics, it also had good wear-resisting property in continuous cutting.