Nicalon SiC/7740复合材料及其断裂韧性的研究

来源期刊：中南大学学报(自然科学版)1990年第2期

论文作者：王零森 陈熙 陈柏新 余庆高

文章页码：184 - 190

关键词：纤维增强复合材料； 断裂韧性； 材料力学性能/碳化硅纤维

Key words：fiberic reinforced composites； fracture toughness； mechanical properties of materials/SiC fiber

摘    要：本研究采用泥浆浸渗技术和热压成形工艺成功地制得了Nicalon SiC束纤维强化7740玻璃复合材料。在热压温度1200℃,压力6.7MPa,持压1h,用氮作保护气体的条件下,材料抗弯强度达780MPa,K_1c达25MPam^1/2(取p_Q=p_max)。还研究了纤维体积含量V_f与K_1C的关系。实验表明:随着V_f的增加,K_1C增加,当V_f达到40％左右时,K_1C达到最大值,尔后随V_f增加而降低。本文对复合材料热压致密化机制和V_f对K_1C的影响进行了讨论。

Abstract: A reinforced nicalon SiC yarn 7740 borosilicate composite with the flexurestrength up to 780 MPa and the fracture toughness, K_1C, of 25 MPam^l/2 (let P_Q=P_max) was produced by hot-pressing the lay-up infiltrated unitapes at thetemperature of 1200℃ under the pressure of 6.7 MPa for 1 h in the atmosphereof N₂. The relationship between fiber volume content, V_f, and fracture tough-ness, K_1C, measured by means of three-point-bend-testing was studied. Theresults show that K_1C increases with the increase of V_f until V_f is about40%. After K_1C reaches to a maximum value, i. e. about 25 MPam^1/2 (letP_Q = P_max), it decreases. The mechanism of hot-densification of composite and the influence of V_fon K_1C were also studied in the present paper.