陶瓷岩板断裂特性与Weibull统计分析及加工可靠性评价

Fracture Characteristics and Weibull Statistical Analysis of Sintered Stone and Evaluation of Machining Reliability

陶瓷岩板已成为现代家居装饰的重要饰面材料和新型家具板材,但其在深加工和服役过程中容易出现开裂和破碎等断裂问题以及强度随着尺寸增大而下降等问题。本研究考察了岩板试件正面和背面方向弯曲受力时的临界应力及断裂特性,分别采用最小二乘法和快速法估算了岩板试件的弯曲强度Weibull模数。结果表明,当试件正面(釉面)作为受拉面时,其平均强度达到80.4 MPa,Weibull模数为27;当试件背面作为受拉面时,其平均强度为52.7 MPa,Weibull模数为22。由此建立了在给定破坏概率条件下岩板加工允许应力的估算方法。同时,提出了降低岩板加工破裂概率的两个关键点:一是提高材料的韧性与强度比值;二是降低加工过程中的动态应力,并使最大动态应力小于岩板的允许应力。

The sintered stone has become an important decorative material and a new furniture plate for modern home decoration,but it is easy to crack and fracture in the process of deep processing and service,and the strength decreases with the increase of material size.In this study,the critical stress and fracture characteristics of sintered stone specimens under flexural tensile stress in front and back directions were investigated,and the Weibull modulus of flexural strength of specimens was estimated by least square method and the maximum likelihood technique,respectively.The results show that when the front(glaze)of the specimen is used as the tensile surface,the average strength reaches 80.4 MPa and Weibull modulus is 27.When the back of the specimen is used as the tensile surface,its average strength is 52.7 MPa and Weibull modulus is 22.A method for estimating the allowable stress value of sintered stone during the processing under given failure probability was established.At the same time,two key points to reduce the fracture probability of sintered stone during processing were proposed.The first is to improve the ratio of toughness to strength of the material,and the second is to reduce the dynamic stress in the processing and make the maximum dynamic stress less than the allowable stress of sintered stone.