Researchers developed several improvements to the fused-silica process over the years. In 1970, researchers discovered that manipulating the rate of heating, temperature and the time at temperature affect the development of the ceramic's mechanical strength in a phenomenon called sintering. The result was 50 percent stronger than previous efforts, yet maintained the requisite electromagnetic properties. By the end of the 1980s, Tech researchers learned that adding aluminoborosilicate fibers to the mix strengthened the material. The shorter fibers also prevented clumping during slip casting, a condition that results in lower density and strength, and large flaws.
Fibers increase the amount of energy needed to break the fused silica material.
And should a crack develop, it would run into a fiber and follow the fiber along a tortuous path. The radomes developed at Tech are widely used for intelligent missile systems such as the Patriot.