In this Phase II program Pepin Associates will improve the C/CSiC manufacturing process and compare the properties of DiscoTex and continuous reinforced laminates. 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. One of these processes will be selected to fabricate and test laminates reinforced with DiscoTex, stretched DiscoTex and continuous fabrics. Needle punching selected laminates will also be performed to evaluate its benefits to increase interlaminar toughness. This added through thickness reinforcement prevents delamination both during processing and in service. Mechanical and thermal test matrices include both room temperature and high temperature testing. In addition Pepin Associates will design and build a torch test rig to evaluate material samples with various reinforcement architectures and densification process history.
Analysis will be performed to model DiscoTex reinforced laminates in both stretched and unstretched conditions. The analysis will 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 small liquid rocket engine. The DiscoTex forming process will be developed to most efficiently form the nozzle extension shape. Samples of the nozzle material will be tested in the torch test rig. The team will also fabricate a spherical shell atmospheric entry vehicle. Both these structures will be delivered to NASA at the end of the contract.
DiscoTex formable preforms will reduce the cost of fabricating complex shaped hot structures which are damage tolerant, reusable, and lightweight. These structures include nozzle extensions and other engine components, aeroshell structures, leading edges, and control surfaces, Atmospheric entry vehicle hot structures reduce vehicle weight and allow for easier inspection. The ability of DiscoTex preforms to more easily create integrated structures will allow more efficient designs to be created.
The DOD services all have active hypersonic programs. DiscoTex formable preforms will have applications to leading edges, control surfaces, and propulsion components for missiles, boost glide vehicles, and other DOD hypersonic weapon systems. DiscoTex reinforced C/C composites could also find industrial markets such as structures for metals and photovoltaic processing