Patent DK-195781-A (DK)
IPC: C04B14/00
Filed: 1981-05-01
Abstract: Formed objects having a continuous matrix which comprises homogeneously arranged bodies (A) 18, 24 of a size of from approx. 50 A to approx. 0.5 μm, such as particles of silica dust, and tightly packed bodies or particles (B) 12 having a size which is of the order of size of 0.5- 100 μm, and which are at least an order of size larger then the respective particles of bodies A, such as Portland cement, and, where appropriate, additionally comprises solid particles (C) which are embedded in the matrix and which consist of a material which has a strength which exceeds the strength of customary sand and stone which are used for normal concrete, such as refractory bauxite, with the particles A being homogeneously distributed, in particular tightly packed, in the cavities between the particles B, are produced from a free-flowing composite material containing a very small quantity of liquid, such as water, and an extremely large quantity of a dispersing agent such as a concrete superplasticizing agent. Test pieces having a Portland cement/silica dust matrix, in which refractory bauxite is embedded, have a higher compression strength than has previously been reported for any cement-based matrix, which means that the matrix material makes it possible to construct larger constructions than was possible using known construction materials such as high-quality concrete and low carbon steel. The Portland cement-based material can be used as a replacement for plastic, glass and steel, as, for instance, for tools for fabricating car body parts by stamping. More generally, the patent describes a novel class of materials, which are not limited to cement systems, where the fundamental principle is that of using known geometric and kinematic principles for bringing relatively large bodies or particles 12 into the desired configuration in relation to each other, in particular into a tightly packed formation, in systems of fine particles or bodies 18, 14 which are 1-2 orders of size smaller than the body or particle systems in which it has previously been possible to use the knowledge of geometry and kinematics for large bodies, with dispersing agents being used to overcome the locking surface forces between adjacent particles which have previously prevented bodies or particles of micro or submicro size from being brought into a tightly packed formation, in agreement with pure geometric and kinematic principles. The use of these principles makes it possible to produce a number of novel materials of previously unknown high quality, such as extremely strong fibre/metal matrix composite materials, where the compression strength and abrasion resistance of the metal matrix are greatly improved by introducing submicro particles A 18, which is possible in association with the particle location principle where locking surface forces are overcome. Despite a very high content of fibres, such as 50% by volume of very strong, extremely thin fibres in the range 5-10 μm, it is possible to introduce tightly packed particles A 18 by forming the particle-fibre system using an auxiliary carrier 20, such as water, which is then replaced with the final interparticle substance, such as a metal, in a subsequently process such as infiltration. <IMAGE>