高性能陶瓷断裂韧性的SEPB评价技术

The SEPB Technique of Evaluation of Fracture Toughness K_(1c) for Advanced Ceramics

本文综述和比较了高性能陶瓷断裂韧性(K_(1c))的各种测试技术,详细研究了桥压法(BridgeIndentation)制备预裂纹技术(SEPB)及基本原理.指出用 SEPB 法测得的 K_(1c)是其他多数方法的下限值,但这是相当可靠和稳定的测试技术,它克服了目前广为采用的 SENB 法的不足之处.对七种典型的高性能陶瓷分别采用五种不同的测试方法测定 K_(1c),比较结果,支持了上述观点.

A review of the techniques of fracture toughness K_(1c) determination for advanced ceramics was made.On the analytical base,a new technique so called“Bridge Indentation”or“ Single Edge Precracked Beam”was investigated,described and analysed on the fundamental principle.It based on the SENB technique and took the advantage of indentation technique, It was found that the SEPB technique gaves lower limit value of K_(1c) to compare with other techniques.It,however,is the most conservative and consistent estimate of K_(1c).The SEPB technique overcomes some short comiogs of SENB technique which was extennsively applied for measuring K_(1c) of advanced ceramics.The comparison of measured results between SEPB,DCB, SENB,SIT and MIT for seven advanced ceramics,including 3 kinds of gas-pressured sintered Si_3N_4,sintered Al_2O_3,Al_2O_3 with 3% Cr_2O_3,and 2 kinds of Y-TZP materials supported the new technique.