AFRL-RX-WP-JA-2017-0316 LARGE FORMAT ADDITIVELY MANUFACTURED TOOLING FOR OUT-OF-AUTCLAVE AEROSPACE COMPOSITES ( PREPRINT )
The aerospace composites industry is plagued with high costs and long lead times for tooling, driving up part costs and delaying design cycles in new production. Tooling also complicates sustainment efforts for the Air Force’s legacy aircraft. Large format additive manufacturing has the potential to address both issues. Printed thermoplastic tools in excess of 0.5 square meters in size will be presented that are capable of curing aerospace-quality epoxy and bismaleimide composites at lower cost and with much quicker lead times compared with conventional tooling. 3D-printable, high-temperature thermoplastics and reinforcing fibers will be investigated to achieve the right balance of strength, dimensional stability, and life from the tooling. A general approach for optimization of print parameters to achieve a high-quality tool will be explored. The ability of these additively manufactured tools to withstand autoclave cures as well as out-ofautoclave processes (some of which will require the tooling to support 7 kg/sq m (100 psi) single-side loading) will be demonstrated. The Air Force’s Low Cost Attritable Aircraft Technology (LCAAT) platform is especially suited for this technology and will be used as a demonstrator for this work.
Effect of Curing Poly( p -Phenylene Sulfide) on Thermal Properties and Crystalline Morphologies
Commercial poly(p-phenylene 
sulfide) (PPS) was thermally cured, which resulted in an increase of molecular 
weight due to cross-linking. Non-isothermal crystallization studies of samples 
cured for up to 7 days at 250?C showed a monotonous increase of crystallization 
temperature compared to pure PPS. However, a further increase of curing time decreased 
the crystallization temperature. The change in the half-crystallization time (t1/2) was similar to the 
crystallization temperature. Thus, the cross-linking of PPS affected 
crystallization behaviors significantly. To a certain 
extent, crosslinks acted as nucleation agents, but excessive cross-linking 
hindered the crystallization. Morphologies observed by polarized optical 
microscopy suggested that thermal curing for as little as 1 day contributed to 
the spherulitic structure having a smaller size, that was not observed with 
pure PPS.
Corporations and the Market for Law
The state competition for corporate law has long been studied as a distinct phenomenon. Under the traditional view, corporations are subject to a unique choice-of-law rule, the internal affairs doctrine (IAD). This rule is explained as a historical accident, or by the special logistics of the corporate contract. The resulting market for corporate law appears to have special characteristics, particularly including the dominance by the single state of Delaware. This paper challenges the traditional view. It shows that the corporate law market is best understood as a special application of the general market for law. Any differences are matters of degree rather than kind, and are explained by considerations underlying enforcement of all choice-of-law contracts rather than by factors unique to corporations. It follows that theories of corporate competition that ignore the broader law market context are incomplete, and that the competition for corporate law carries lessons for the law market generally. Moreover, the connection between the corporate and other law markets has implications for the nature of corporate law, the constitutional status of the IAD, the scope of the IAD, and for the relationship between state and federal law.