Stereology of grain-boundary precipitates

Grain-boundary precipitates coexist with matrix precipitation in many alloys. Depending on the orientation of the sectioning plane, particle sections appearing in the matrix on a plane of polish will arise from both grain boundary and matrix participate particles. The errors associated with assuming that the only GBP particles on a section are the ones appearing on the grain-boundary traces are discussed and evaluated. The corrections required are shown to be small, but may nonetheless be important. In addition, a dimensionless grain-boundary affinity parameter has been derived that indicates the tendency of the precipitate to occur on the boundaries rather than the matrix.