TWI Industrial Member Report Summary 1057/2015
By Melissa Riley
Composites are increasingly being used to make a wide range of products including aircraft, cars, medical implants and sports goods. However, they lack some of the functionality of their metallic counterparts. To provide this functionality, coatings are required but the application of well adhered, functional coatings onto polymer composites is challenging, due to the low thermal tolerance of many polymer composites and the high temperatures associated with many engineering coating processes. TWI has successfully demonstrated the feasibility of coating composites via thermal and cold spraying processes and has developed a range of coatings for composite materials, including electromagnetic shielding, thermal management, lightning strike protection, wear and tooling applications. An entirely new approach to the problem has enabled the application of thick thermally sprayed metallic coatings. These coatings are machinable and may provide exciting solutions to engineering challenges being faced in the aerospace, defence and automotive industries today. The coatings enhance the surface properties of composites by providing greater resistance to heat, wear, corrosion, or cavitation, or providing electrically conductive, radar absorbing properties and/or reduced IR detection. This report reviews the state of the art and methodologies for coating composites, technical challenges and potential applications of the technology.