In conventional ultrasonic non-destructive condition monitoring, testing personnel use their testing experience to interpret faults while analyzing the echo ultrasonic. Due to the coarse structure of the material, the ultrasonic wave attenuates more, which sometimes gives a false impression of a defect and provides unreliable results. The conventional inspection method is too subjective and relies heavily on the efficiency of testing personnel, so the inspection reliability is low. To overcome these limitations, a multi-interrogation ultrasonic technique and correlation of several parameters such as attenuation, acoustic velocity and grain size with material characteristics are suggested in this article.1 IntroductionNon-destructive testing (NDT) are the testing of materials, for surface or interior. defects or metallurgical condition, without making it unfit for service. There are various NDT methods to inspect internal defects of complex surface parts, e.g. radiography, eddy flow, ultrasound, etc. Among these testing techniques, ultrasonic testing plays an important role due to its strong penetration, good direction, high sensitivity, low comparative overall cost and harmless to human body and parts material. Ultrasound [1, 2, 3, 4] is a highly effective non-destructive condition monitoring method that can detect even incipient defects. Thus, mean time between failures (MTBF) increases due to proactivity and reduces mean time to repair (MTTR) by improving troubleshooting capabilities. Ultrasonic non-destructive testing methods [5] play an important role in the physical characterization of engineering materials and in the assessment of their quality and suitability for service in structures. In a wide range of different NDT methods... middle of paper ......, NDT and E International (2008).[10]. Bohren Craig F., Huffman Donald R.: Absorption and scattering of light by small particles, Wiley, 2007.[11]. Lavender JD: Ultrasonic testing of steel castings, Steel Castings Research and Trade Association, England, 1976.[12]. Napolitano RE: ASTM Particle Size Index Measurement, Materials Science and Engineering, Lowa State University.[13]. Hyun Lee Joon: Non-destructive characterization of metal matrix composites by ultrasonic measurement, Peragmon (1995).[14].http://www.ndted.org/EducationResources/CommunityCollege/Ultrasonics/Physics/attenuation.htm. Community College, nd online.[15]. Anson LW, Chivers RC and Puttick. E.: On the feasibility of detecting fatigue damage before cracking in metal matrix composites by ultrasonic techniques, Elsevier Science Limited: Composite science and technology (1995).