07-13-10 ⊗ ATC Materials was awarded a Phase I SBIR from the Missile Defense Agency which began April 30, 2010. The purpose of the work is to use Hotblox technology to create an injection moldable in-situ reinforced barium aluminosilicate (better known as IRBAS, a Lockheed Martin patented material) material for missile radomes. Currently, IRBAS is manufactured using a slip casting process in which parts are machined in the sintered state where the material has very high hardness. Because of this hardness, the machining process is difficult and expensive. ATC Materials' goal is to create an injection molded IRBAS radome that can be molded to near-net-shape and thus, minimizing or eliminating machining.

ATC Materials IRBAS SBIR Abstract

The objective of the proposed work is to validate the concept of an injection moldable  in-situ reinforced barium alumino silicate (IRBAS) missile radome using a pre-ceramic siloxane binder system.

IRBAS is a Lockheed Martin patented material that is currently used as the radome on the PAC 3 missile. IRBAS is well suited for missile radomes due its high hardness, high temperature capability, high strength and low dielectric constant.  Although IRBAS is an excellent radome material the cost of machining the blank to the final prescription is expensive.  This effort has the potential of reducing the cost of fabricating IRBAS radomes by producing a more near net shape requiring minimal machining reducing overall fabrication cost.  

American Technical Coatings, Inc. (ATC Materials) has developed a pre-ceramic siloxane binder system that enables injection molding of various ceramics. The use of the binder system and injection molding can create parts with superior dimensional tolerances and surface finish. Because of this, the amount of post-sinter machining can be reduced and part cost can be greatly reduced.

The Phase I project will build on work that ATC Materials has completed to date using the Hotblox binder with IRBAS to mold missile radomes. This material system has the following potential advantages:

1. The process can be precisely controlled and the need to scrap parts, minimized
2. Parts can be molded to near-net shape with very good surface finishes requiring little, if any, final machining or polishing.

These advantages will lead to overall benefits of significantly reduced production cycle times and significantly reduced cost. The integration of ATC Materials’ technology and IRBAS will not only reduce the cost of manufacture for missile radomes, it will also open up the use of IRBAS to other industries and markets.

In Phase I, ATC Materials will optimize formulation, mixing and molding processes.  ATC Materials will work with Lockheed Martin to develop a sintering process and to characterize the material.  At the end of Phase I, ATC expects this project will result in an injection moldable IRBAS material that has been molded into subscale radomes (4 in. tall) and that has been characterized (TRL=3) for use in missile radome applications.