Nondestructive Inspection Technique for Detecting Defects in Metal Matrix Composites

The objective of this proposal is to develop a Non-Destructive Inspection (NDI) system for detection of porosity and debonds in the Metal Matrix Composite (MMC) wear surfaces of Tank Track Shoes (TTS). TTS quality must be such that no further inspection isnecessary after it has passed an initial production acceptance test. The part is placed in service where it will remain until it reaches a recommended service life and is replaced. Thus the MMC must be free of porosity and must adhere tightly to themetallic substrate to conserve its structural integrity. In this project Physical Acoustics Corporation (PAC) proposes the use of the Acoustic Guided Lamb Wave (AGLW) technique for the evaluation of Al/SiC MMC wear layer on 356-T cast aluminum TTS. PACwill demonstrate that the AGLW technique can detect porosity and cracks in the MMC wear layer, and debonds in TTS. Also, PAC will demonstrate its ability to develop and manufacture a portable and easy to use AGWL NDI system. It is anticipated that theresults of this program will lead to the development of a portable ceramic MMC inspection and evaluation system that can be used to assess MMC composite structures. The prototype inspection system will be specifically designed for use in the track shoesfor the U.S. Marine Corps' Advanced Amphibious Assault Vehicle (AAAV) and the Army's Crusader and Bradley Fighting Vehicles (BFV). The system will be portable and be useful in the NDI of MMC structural components of aircraft and Navy's ships andsubmarines, and in a broad range of MMC applications within DoD. In the non-military field, a system of this type will find applications in the automotive industry, as new automotive engines and pistons are manufactured using MMCs and in the in theaerospace and power generating industries where high-temperature corrosion resistance components such as engine turbine blades are more and more often manufactured using MMCs.