Method for embedding optical fibers in an aluminum matrix by ultrasonic consolidation

The overall aim of the research, part of which is outlined in this paper, was to utilize the ultrasonic consolidation (UC) process for the fabrication of smart metal structures, capable of measuring an external stimulus and responding to this stimulus by adapting its structure accordingly through embedding both active and passive functional elements. This paper presents a fundamental study of embedding methods for the fabrication of optical fibers embedded within aluminum structures. The methods considered in this paper produced embedded optical fiber specimens in which large amounts of plastic flow were observed within the matrix. The matrix material deformed around the fibers, resulting in fully embedded optical fibers capable of transmitting a bright light source and without damaging the fibers. Based on light responses, a general process window was drawn to show the range at which optical fibers can be embedded within aluminum structures using the UC process. The outcomes lay down initial investigative principles for the further development of the technology for embedding or cladding of optical fiber sensors, such as fiber Bragg grating devices, within or on metal structures: for example, the cladding of large free-form metal structures or smart "skinned" metal foam or metal honeycomb structures.