TiB_2焼結体の力学的性質に及ぼすZrO_2添加の影響

概要

論文の詳細を見る
Ceramic TiB_2 composites with up to 40 wt% ZrO_2 or 2 mol%Y_2O_3-ZrO_2 were fabricated by hot isostatic pressing (HIP) with glass encapsulation. The effect of addition on the mechanical properties and microstructure of TiB_2 HIP'ed bodies was investigated. The addition of ZrO_2 or 2 mol%Y_2O_3-ZrO_2 was very effective in improving the 3-point bending strength of TiB_2. The 3-point bending strengths of TiB_2 containing 10 wt% ZrO_2 and 10-20 wt% (2 mol%Y_2O_3-ZrO_2) were 1160-1200 MPa, which were about three times higher than that of monolithic TiB_2 (450 MPa). The 3-point bending strength was dependent on the monoclinic ZrO_2 ratio (monoclinic ZrO_2/monoclinic ZrO_2+tetragonal ZrO_2) and the monoclinic ZrO_2 content in the HIP'ed bodies. To obtain HIP'ed bodies with strengths higher than 1000 MPa, the ratio of monoclinic ZrO_2 must be less than 60% and the monoclinic ZrO_2 content must be less than 10 wt% in HIP'ed bodies. Vickers hardness and fracture toughness were also affected by the addition of ZrO_2 and 2 mol%Y_2O_3-ZrO_2. The Vickers hardness of HIP'ed bodies decreased with increasing ZrO_2 and 2 mol%Y_2O_3-ZrO_2 content. On the other hand, the fracture toughness increased linearly with increasing ZrO_2 and 2 mol%Y_2O_3-ZrO_2 content. The fracture toughness of TiB_2 containing 30 wt% ZrO_2 was 8.2 MPa・m^<1/2>. This toughning was caused by crack deflection, however, stress induced transformation was not observed. TEM observation showed no grain boundary phase which was resulted from the reaction between TiB_2 and ZrO_2. However, EDS analysis showed that Ti and Zr existed in the ZrO_2 and TiB_2 grains, respectively, indicating that diffusion occured between TiB_2 and ZrO_2.
社団法人日本セラミックス協会の論文
1992-03-01

TiB_2焼結体の力学的性質に及ぼすZrO_2添加の影響

スポンサーリンク

概要

著者

関連論文

スポンサーリンク