HIGH-TEMPERATURE LOAD TRANSFER IN NICALON/BMAS GLASS-CERAMIC MATRIX COMPOSITES

摘要

High-temperature load transfer characteristics of Nicalon fiber-reinforced BMAS glass-ceramic composites were studied. Specimens were crept at 1100 deg C under constant tensile load to accomplish load transfer from the matrix to the fibers, and then cooled under load. Upon removal of the load at room-temperature, the matrix was put into compression by the elastic recovery of the fibers. This compressive residual stress in the matrix increased the proportional limit of the composite as determined by room-temperature tensile stress-strain behavior. Changes in the state of residual stress in the matrix were also confirmed with X-ray Diffraction measurements (XRD).