Influence of zirconium-based alloys on manufacturing and mechanical properties of ultra high temperature ceramic matrix composites

For the continuous development of ultra high temperature ceramic matrix composites manufactured using reactive melt infiltration (RMI), the influence of three different melt alloys and two preform routes on mechanical behaviour and melt infiltration is investigated. Contact angle and viscosity measurement are performed to describe the melt infiltration process. The purpose of these experiments is to further understand the RMI process and increase the mechanical performance of the material. The infiltration height of molten metals within capillary systems depends on the measured contact angles and viscosity as well as the different phases present in the preform, matrix and fibre coating. In order to successfully maintain mechanical performance, minimal reactivity between the melt and coating/fibres is desired. Resulting phase formations, for each manufacturing step, are investigated and analysed using SEM, EDX and XRD. Mechanical performance is determined using flexural strength by three-point-bending, achieving close to 400 MPa with 0/90∘ fabrics.