Research progress of syntactic foams used in solid buoyance material

Abstract

Buoyant materials, as an important counterweight material of the deep-sea devices, play an important role in providing the equipment with enough buoyance as much as possible. Solid buoyant materials (SBMs) have received extensively attention in deep-water surveying and development and petroleum exploration fields in recent years due to their low density, high strength and low water absorption characteristics.In this paper, the classification and the application of SBMs and their recent developments both at home and broad were firstly discussed. Typically, the SBMs can be mainly divided into the chemical and the composite syntactic foams according to their chemical composition and the composite syntactic foam was especially elaborated in this study. Secondly, four basic types of the composite syntactic foams, namely metal-, polymer-, and ceramic- matrix and other types of the syntactic foams, based on their chemical composition of the matrix and the reinforcement. The influence factors such as the essential composition, the surface microstructure, and the loading rate on the physical, mechanical, and the failure mode of the syntactic foams were summarized. The dynamical behavior and failure mechanism under different loading rates can be analyzed and revealed by the computed X-ray tomography technique combined with the finite element method. The prospects of improving overall mechanical performance and advanced experimental characterization methods of syntactic foams are summarized as follows: the overall mechanical performance can be improved by modifying functional groups of filler and resin matrix or adding a second reinforcement phase; the microstructure can be characterized and the failure mechanism revealed by means of μ-CT and scanning electron microscope.

Keywords

• solid buoyant material
• syntactic foam
• matrix
• filler
• fracture mechanism