Scanning ion microprobe analysis of composite materials

Abstract

SUMMARY Applications of scanning ion imaging with high lateral resolution in the microchemical investigation of metal – and ceramic‐matrix composites are described. The technique, which combines a scanning ion microprobe with secondary ion mass spectrometry (SIMS), is ideally suited to the study of complex, multicomponent composite structures. Most elements can be detected with good sensitivity, enabling the determination of spatial distributions for major and minor elements. Analytical images obtained with this technique reveal unprecedented chemical information about interfacial segregation and interdiffusion phenomena. As examples, the characterization of both ceramic–matrix (Al borate–SiC) and metal–matrix (Ni alloy–Al2O3) composite materials is described.

Imaging with Mass Spectrometry

“…Mass spectral imaging requires the effective creation of secondary ions. As noted earlier, and by other authors, , the number of molecules available for analysis becomes vanishingly small as the pixel size approaches the size of the ion beam probe. This problem is particularly acute for static SIMS imaging where surface damage limits the number of molecules that are desorbed from a given area.…”

Ion microprobe studies of reactions in squeeze‐cast aluminium alloy matrix composites

“…The above results demonstrate that high-spatial-resolution imaging microanalysis with secondary ion mass spectrometry (SIMS) is extremely powerful and efficient id the study of composites. Chief among the benefits of using SIMS over other techniques is that most elements can be detected with good analytical sensitivity and that bulk polished samples can be examined (Soni et al, 1993b;Williams et al, 1993). Compositional imaging samples every point in an image matrix without bias, which unfortunately is not the case when an analyst is selecting locations for point analyses.…”

“…A scanning ion microprobe (focused ion beam), in conjunction with SIMS, offers good lateral resolution and excellent analytical sensitivity for most elements. The merits and limitations of the SIMS technique for the characterization of composite materials have been discussed previously (Soni et al, 1993a(Soni et al, ,b, 1995Williams et al, 1993). In a recent study, Mogilevsky et al (1994) used SIMS to microanalyse Al-Si-Mg-Cu alloys reinforced with Saffil or Fiberfrax (45155 mixture of alumina and silica) fibres.…”

Ion microprobe investigations of interfacial phenomena in composites

“…In contrast, there has been relatively little effort to characterize the matrix/reinforcement reactions using modern microanalytical techniques. [1][2][3] It is reasonable to postulate that a fuller understanding of interfacial phenomena will promote the design and development of advanced composite materials. Scanning ion imaging microanalysis is one tool that can be used to increase our knowledge of processing-induced microchemical phenomena.…”

“…transparency for examination in the transmission electron microscope (TEM). 3 The capabilities of SIM/SIMS for the analysis of composite materials are illustrated here by case studies of an alumina-reinforced superalloy, an alumina-reinforced aluminum alloy, and an SiC-reinforced aluminum borate.…”