The iron-base INCOLOY alloy MA 956 contains about 20% Cr, 4.5% Al, 0.5% Ti, and about 0.5% Y2O3. It can be used at operating temperatures of over 1300°C in a corrosive atmosphere.[8] MA 956 also has excellent fabricability. It can be cold-worked and can be joined by several welding techniques. MA 956 sheets can be bent more than 150° around a diameter equal to twice the sheet thickness.[5] The first ODS material designed as a structural system was SAP (Sintered Al Powder) as developed by Irmann.[9] Sintered Al Powder (SAP) displayed a greater strength than pure Al and no changes were observed after extended heating near the melting point. In 1957, Benjamin et al.[10] developed further SAP. Bars of SAP were made by a mixture of 1 to 10% vol % Al2O3 powder in pure Al powder. The Al2O3 particles in SAP exhibit a wide distribution of sizes (~10 nm to 1 µm), as presented in Fig. 2.4. In order to maximize the strength of Al-Al2O3 ODS alloys it was desired to obtain a finer and more uniform distribution of the Al2O3 dispersion in the Al matrix.