采用单探头直接接触纵波探伤的方法,检测了9根WC-10 Co硬质合金试样的超声波衰减系数α,结合试样的密度、晶粒度、断裂韧性KIc、维氏硬度及抗弯强度进行分析。结果表明:合金的晶粒度越小,超声波衰减系数α越大,断裂韧性越高,而超声波衰减系数与密度、硬度和抗弯强度没有直接的关系。可用超声波在WC-10 Co硬质合金中的衰减行为来评估材料的韧性,从而替代有损的机械方法。

Ultrasonic Evaluation of WC-Co HardmetalsYAN Li,SHAO Gang-qin,XIONG Zhen,SHI Xiao-liang,DUAN Xing-long (State Key Laboratory of Advanced Technology for Materials Synthesis & Processing,Wuhan University of Technology,Wuhan 430070,China)The method of single detector,direct contact and longitudinal wave were used in this research.Ultrasonic wave attenuation coefficient of nine WC10 Co hardmetals samples were tested,while fracture toughness values were obtained by indentation method.SEM was performed to observe the sections of the samples.Distributions of the WC grains were analyzed.Density,Vickers hardness and transverse rupture strength were also tested.The relationships among ultrasonic wave attenuation coefficient,mean grain size,fracture toughness,density,Vickers hardness and transverse rupture strength were studied.Results showed that with the decrease of the mean WC grain size,the ultrasonic wave attenuation coefficient and the fracture toughness value increased.However,ultrasonic wave attenuation coefficient had no direct relation with density,Vickers hardness and transverse rupture strength.It was concluded that ultrasonic wave attenuation coefficient could be used to evaluate the fracture toughness of WC-10 Co hardmetals,instead of destructive mechanical method.WC-Co hardmetals;ultrasonic wave attenuation coefficient;mean grain size;fracture toughness;mechanical properties