Formable Preform for Complex Shaped Hot Structures

In this Phase II program Pepin Associates will improve the C/CSiC manufacturingnbsp;process and compare the properties of DiscoTex and continuous reinforced laminates.nbsp; Further comparisons will be made of laminates SiC densified with polymer infiltration and pyrolysis (PIP) with those SiC densified using the melt infiltration (MI) process.nbsp; One of these processes will be selected to fabricate and test laminates reinforced with DiscoTex, stretched DiscoTex and continuous fabrics.nbsp; Needle punching selected laminates will also be performednbsp;to evaluate its benefits to increase interlaminar toughness.nbsp; This added through thickness reinforcement prevents delamination both during processing and in service.nbsp; Mechanical and thermal test matrices include both room temperature and high temperature testing.nbsp; In addition Pepin Associates will design and build a torch test rig to evaluate material samples withnbsp;various reinforcement architectures and densification process history.nbsp;nbsp;Analysis will be performed to model DiscoTex reinforced laminates in both stretched and unstretched conditions.nbsp; The analysis willnbsp;infer constituent material properties from previously measured data on composites fabricated from both stretched and unstretched DiscoTex.. Using the resulting material model, material properties for arbitrary laminate stacking sequences, fiber volume fractions, and degrees of ply stretching can be estimated.Pepin Associates will fabricate a nozzle extension for a smallnbsp;liquid rocket engine.nbsp; The DiscoTex forming process will be developed to most efficiently form the nozzle extensionnbsp;shape.nbsp; Samples of the nozzle material will be tested in the torch test rig.nbsp; The team will also fabricate anbsp;spherical shell atmospheric entry vehicle.nbsp; Both these structures will be delivered to NASA at the end of the contract.nbsp;