Additive Manufacturing of Aerospace Composite Structures: Fabrication and Reliability

Abstract

More than twenty years have passed since we invented polymer–clay nanocomposites (PCN), in which only a few wt.-% of silicate is randomly and homogeneously dispersed in the polymer matrix. When molded, these nanocomposites show superior properties compared to pristine polymers such as tensile strength, tensile modulus, heat distortion temperature, gas barrier property, and so on. The number of papers on PCN has increased rapidly in recent years, reaching over 500 only in 2005. As the pioneers of the new technology, we will review its history highlighting our works. Epoch-making events of PCN are as follows: In 1985, The first PCN, nylon 6–clay hybrid (NCH), was invented. In 1987, NCH was first presented at the ACS Fall Meetings. In 1989, NCH was presented at the MRS Fall Meetings, firing PCN. In 1989, Toyota launched cars equipped with a NCH part. In 1996, Clay was found to cause a memory effect in liquid crystals. In 1997, Gilman of NIST et al. found revolutionary fire retardency in NCH. In 1997, PP-clay nanocomposite was prepared. In 1998, Compounding method for producing NCH was established. In 2002, Haraguchi of Kawamura Institute of Chemical Research et al. invented a nanocomposite hydrogel. So far only nylon-clay nanocomposites are used in practice, but other PCN will become increasingly useful in the future.