Ultrasonic Nondestructive Testing Technique Study Of W/Al Composites Materials

The W/Al composites materials were prepared by hot isostactic pressing method in this study. Nondestructive testing technique of W/Al composites materials was nondestructively studied by ultrasonic C-scan (UTC-Scanning) and x-ray nondestructive testing method to find out the artificial defects inside of W/Al composites materials. Tipical micro-structure of extruding W/Al composites materials including morphology, W/Al distribution and main composition were analyzed by ultrasonic C-scan, x-ray nondestructive testing method and SEM/EDS. At the same time, micro-structure evolution of W/Al composites materials including morphology, W/Al distribution and main composition after hot isostactic pressing, extruding and forging were comparatively studied by ultrasonic C-scan nondestructive mothed.The main conclusions are as follows:(l).The optimized inspection parameters of traditional ultrasonic C-scan for W/Al composites materials are as follows:velocity:10 mm/s, step:0.2 mm, gain:40 dB, the more the better for pulse energy.(2). Focal depth region is the optimized investigate area when we have the focal point inside of W/Al composites materials. In focal depth region, pulse energy the lower the better to have ultrasonic C-scan nondestructive testing of W/Al composites materials.(3).The artifical defects of Al2O3 particles inside of W/Al composites materials can be successfully detected via ultrasonic C-scan. The size of the artifical defects is millimeter level.(4).After extruding, two kinds of typical micro structure occurred in W/Al composites materials:high density band and low density band. These bands paralleled to the direction of extrusion. It is Al of the low density band structure’s main component, as for the high density band structure, tungsten’s mass fraction is a little higher than normal.(5). W/Al composites materials prepared by hot isotactic pressing exhibit uniform micro structure, but there are some segregation structures whose main component is Al exist in part areas. After extrusion, these segregation structures which are rich of Al turn to band structures and paralleled to the direction of extrusion, extrusion is helpful to uniform W/Al composites materials. Having forging process to W/Al composites materials along extrusion direction, results show that forging process can basically eliminate segregation structure and decrease the width of band structure which is rich of Al in W/Al composites materials, making W/Al composites materials a uniform structure.