Synthesis and mechanical properties evaluation of IN SITU Ni3Al-TiC composite
Edward Fraś, Andrzej Janas, Andrzej Kolbus Akademia Górniczo-Hutnicza, Wydział Odlewnictwa, ul. Reymonta 23, 30-059 Kraków Stanisław Wierzbiński Akademia Pedagogiczna, Instytut Techniki, ul. Podchorążych 2, 30-048 Kraków
Annals 2 No. 4, 2002 pages 171-175
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abstract Metal matrix composites (MMCs) are a new range of advanced materials used mainly at elevated temperatures where existing materials are not suitable for use. The materials have a combination of different superior properties to an unreinforced matrix, which can result in a number of service benefits, among which are: increased strength, higher elastic modulus, higher service temperature, improved wear resistance, decreased weight, better fatigue resistance, high toughness and impact properties, low thermal shock, high electrical and thermal conductivity, low coefficient of thermal expansion and high vacuum environmental resistance. By varying the matrix material and particle content, the desired strength and ductility properties can be designed. The discovery by Aoki and Izumi of a method of plasticization of the polycrystalline Ni3Al intermetallic phase by the addition of boron, which while segregating to the boundaries increases the strength of cohesion between the grains. The boron reduces the intermetallic brittleness, as well as contributes to the increase of consolidation of a solid solution by blocking the dislocations. Figures 2a, b show the mechanical characteristics of the NiAlB alloys in the system of σ -ε-B wt.% (Fig. 2a) and R0,2-B wt.% (Fig. 2b) systems for the specimens deformed at room temperature in compression tests, respectively. In Figure 3 shows the influence of boron contents on the uniform elongation determined in the compression test. On the both, Figure 2b and Figure 3, is visible that optimum boron contents is 0.05 wt.%. Metallographic and scanning pictures on Figures 6-9 presents phase Ni3Al before and after synthesis TiC. The paper bring an information about SHSB method of manufacturing new generation of composites based on Ni3Al intermetallic phase reinforced TiC particles.