Abstract: Electromagnetic wave absorbing materials comprising magnetic alloy particles and an insulating matrix are disclosed. The magnetic alloy particles comprise a transition metal such as Fe and/or Co, and further comprise at least one refractory metal such as Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W. The magnet alloy particles may further include Ni and/or Al, or other alloying additions which provide the desired absorption characteristics. In a preferred embodiment, the magnetic alloy particles comprise an Fe—Cr—Ni—Al alloy. The insulating matrix of the electromagnetic wave absorbing material may comprise a water miscible polysilicate or a refractory cement. The materials may be provided in the form of coatings that are applied to a substrate, such as the hot engine exhaust area of an aircraft. The electromagnetic wave absorbing materials are capable of functioning at very high temperatures for extended periods of time while retaining satisfactory electromagnetic wave absorbing properties.

Abstract: Electromagnetic wave absorbing materials comprising magnetic alloy particles and an insulating matrix are disclosed. The magnetic alloy particles comprise a transition metal such as Fe and/or Co, and further comprise at least one refractory metal such as Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W. The magnet alloy particles may further include Ni and/or Al, or other alloying additions which provide the desired absorption characteristics. In a preferred embodiment, the magnetic alloy particles comprise an Fe—Cr—Ni—Al alloy. The insulating matrix of the electromagnetic wave absorbing material may comprise a water miscible polysilicate or a refractory cement. The materials may be provided in the form of coatings that are applied to a substrate, such as the hot engine exhaust area of an aircraft. The electromagnetic wave absorbing materials are capable of functioning at very high temperatures for extended periods of time while retaining satisfactory electromagnetic wave absorbing properties.