Metal-ceramic composite materials have been investigated for several years. The combination of a ductile metal with hard and brittle ceramic offers a range of high strength and wear resistant materials. [1][2][3] Metal matrix composites (MMC) are denoted by the ability of plastic deformation and high strain with reinforcements of ceramic particles. Ceramic matrix composites (CMC) with typical ceramic behavior are advantageous in terms of chemical stability, wear resistance, and hardness with elevated fracture toughness caused by metal phase.In recent times, a new type of steel has been developed: TRIP-steel (TRansformation Induced Plasticity). The key to excellent properties is a martensitic phase transformation from austenite to martensite on mechanical load. [4] This change is related with a considerable increase in toughness higher than in normal steels. As a secondary effect, an increase of strength can be observed. Metastable austenitic CrÀNiÀsteels offer tough and high-strength applications combined with economical advantages. [5] The ability of transformation is besides stress and temperature a function of the chemical composition. Austenite stabilizing elements and there factorized impact in comparison to nickel is summarized in formula (1). For sufficient TRIP-effect a calculated sum of 12-16 is necessary. Due to corrosive behavior additions of chromium are necessary in stainless steel. Ferrite phase is stabilized by chromium and other alloying elements as presented in formula (2). As a result a Cr-equivalent of 16-20 enables stainless steel with improved mechanical properties. The most critical alloying element with respect to economical reasons is nickel with up to 90% of costs in steel. Replacing nickel partially by manganese which is 30 orders of magnitude lower in costs offers the ability of cost reductions at similar mechanical properties. For this reason CrÀMnÀNiÀsteels are of interest for both metal and composite applications. [6] Ni À equivalent : %Ni þ 30%C þ 18%N þ 0:5%Mn þ 0:3%Co þ 0:2%Cu þ 0:2%Al(1) Cr À equivalent : %Cr þ %Mo þ 1:5%Si þ 0:5%W þ 0:9%Nb þ 4%Al þ 4%Ti þ 1:5%V(2) Zirconia (ZrO 2 ) ceramics have been used since decades in a wide range of applications due to their corrosive, chemical, and mechanical properties. ZrO 2 appears in three modifications: between melting and 2370 8C the cubic phase (c-ZrO 2 ) is stable. Further cooling leads to transformation into the tetragonal phase (t-ZrO 2 ) and below 1170 8C highly distorted monoclinic ZrO 2 (m-ZrO 2 ) is thermodynamically preferred. The t $ m transformation appears with a volume change of 3-5% which COMMUNICATION Ceramic-steel compound materials are used in a wide range of applications up to date. Major advantages are the mechanical properties due to the combination of brittle ceramic with tough steel. This study deals with effects of the sintering process on austenitic TRIP-steel/Mg-PSZ composite materials for mechanical load applications. Both, the FeÀCrÀNiÀsteel and partially stabilized zirconia offer their special mechanical b...

The combination of highly reactive raw materials with an optimized set of dopants results in high density Mn Zn ferrites. The use of non-calcined raw materials has the advantage of simplified processes and improved cost efficiency of the industrial realization. Lowest power losses and highest saturation flux densities could be achieved as a result of substantial investigations. Both properties require a dense and defect-reduced microstructure. The spinel formation and the grain growth were optimized due to the required grain size, the composition and the grain boundary thickness. Usual additive oxides like CaO, SiO 2 and Nb 2 O 5 were amended by V 2 O 5 and SnO 2 as eutectic control. Increased transport capability for the initial chlorine content of iron oxide at moderate temperatures could be enhanced by optimized shrinkage behavior. Consequently all results were adapted to commercial raw material qualities with the result of highest performance power transformer ferrites in the frequency range up to 300 kHz.