TECHNOLOGY AREA(S): Materials/Processes
The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 5.4.c.(8) of the solicitation.
OBJECTIVE: Develop a methodology for producing low-cost, high-performance thermoplastic composite structures that contain highly detailed features for missile and aviation applications.
DESCRIPTION: Fiber reinforced thermoplastic matrix composites (TPMCs) provide improved damage tolerance, faster processing and assembly, reduced joint weight, virtually unlimited shelf life with minimal storage requirements, and recycling options which thermoset composites typically cannot offer. Through automated processing, TPMCs allows the potential for mass production of high stiffness/strength thermoplastic composites at lower costs. Despite the above advantages, the true benefits of TPMC missile structures have been limited by the constraints of available fabrication methods. For example, autoclave and compression molding techniques can process continuous fiber preforms that offer high strength and stiffness but are generally more suited to producing fairly simple geometric structures (e.g., plates, cones, box-structures). Injection molding methods, on the other hand, offer the ability to produce highly complex geometries, but even the most advanced molding compounds do not offer the structural performance of continuous preforms.
An ideal TPMC structure would combine compression molded and injection molded components into a single structure to retain cost and performance benefits. This ideal TPMC fabrication process should have a minimum cost reduction of 20% from traditional autoclave and compression molding manufacturing techniques. Joining techniques for TPMC components is an area of active research but this is a secondary process that decreases through-put and often requires access to the bond line for processing. For structures that could benefit from attaching multiple injection molded components to compression molded components, a direct method of attachment is desired.
PHASE I: Develop a design and fabrication strategy that combines multiple TPMC processing techniques for producing a low-cost, high performance TPMC structure. Structural properties should be a minimum of 50 Ksi tensile strength, 50 Ksi compression strength and 7 Msi tensile and compression modulus. The strategy should be able to accommodate producing structures as large as 1m x 1m, but contains detailed features, such as internal ribbing and other traditional stiffening elements. Demonstrate the feasibility at the coupon level to join TPMC components that have been produced by multiple fabrication methods.
PHASE II: Refine the design and fabrication strategy for producing more representative structures. Perform comprehensive studies and analyses of the structure to determine optimal fabrication method for the individual subcomponents to balance cost and performance. Perform mechanical tests to demonstrate performance.
PHASE III DUAL USE APPLICATIONS: Upon successful completion of the research and development in Phase I and Phase II, produce prototype structures that can be demonstrated in field tests. Scale-up the design and fabrication strategy to be compatible for low rate and full production rate quantities. Demonstrate the TPMC structure can provide cost, weight, and performance benefits to applications outside the military.
KEYWORDS: thermoplastic matrix composites, thermoplastic matrix composites missile structures, injection molding, back molding, joining technique of thermoplastic, cost effective fiber reinforced thermoplastic matrix composites.