SE505824C2 - Reinforced materials, process for making them and their use - Google Patents

Abstract

Inclusion-reinforced material (I) contains a metallic or ceramic matrix. Finely divided mixed crystals of transition metal borides of the AlB2 type and/or crystals of the related W2B5 type is/are used as inclusion particles. (I) is produced by mixing finely divided mixed crystals of transition metal borides of the AlB2 type and/or crystals of the W2B5 type into the flowable matrix and solidifying the mixt. Specifically, mixed crystals contg. Ti-Cr, Zr-, Nb-, Ta-, W- or Mo-borides, esp. TiB2, CrB2, ZrB2, VB2, NbB2, TaB2, WB2, or MoB2, are used, pref. CrB2/WB2 mixed crystals or TiB2 mixed crystals, esp. TiB2/CrB2-, TiB2/VB2-, TiB2/ZrB2- and/or TiB2/WB2-mixed crystals. The inclusions have a particle size of 0.05-500 (esp. 1-50) microns and are of plate-form. USE/ADVANTAGE - (I) can be used as and in the prodn. of wear- and temp. resistant components and elements (claimed). It has improved mechanical, physical and chemical properties.

Description

15 20 25 30 35 505 824 2 a pressure component perpendicular to the crack flank has a closing or at least slowing effect on the development of the crack. This means that the second reinforcement mechanism, the micro-crack reinforcement, also becomes available.

If numerous interfaces occur in the vicinity of the tip of the crack, in a so-called process zone, and so-called micro-cracks are formed, their formation and growth contribute to an increase in the fracture work of the main crack. Emerging micro-cracks can increase the tensile strength by contributing to a branching and deflection of the crack. However, excessively high internal stresses between particles and matrix can also cause spontaneous microcracking or also lead to several microcracks merging to form larger cracks that are harmful to the material. The thermophysical properties of the stored particles must therefore be such that there is an optimal, i.e. toughness-increasing stress in size and direction.

The production of new materials by embedding in the matrix phase is thus an extremely complicated procedure, especially in view of the fact that the aim is to produce a new material with improved properties in several respects without, however, a significant improvement of an intrinsic material. cabinets go beyond other properties. The many possibilities for the interaction between grain morphology, chemical composition and thermophysical properties of stored particles with the matrix phase can lead to reinforced materials of the most varied kinds and finally make it impossible to predict with certainty how a reinforcement material works in a matrix.

The object of the invention was therefore to produce materials and shaped bodies on the basis of thermodynamic, biphasic or multiphase, storage-reinforced, metallic or ceramic matrixes with improved mechanical, physical and / or chemical properties in relation to the unreinforced material or comparable, reinforced materials and moldings.

In particular, it is intended to produce materials with improved modulus of elasticity, strength, hardness, fracture toughness, thermal expansion coefficients, electrical and thermal conductivity and high temperature properties. The object is achieved with materials and shaped bodies on the basis of by reinforcements reinforced by deposits and thus thermodynamically at least two-phase, metallic or ceramic matrixes according to the invention by depositing in the matrixes of these materials and shaped bodies fine-grained mixed crystals of transition metal borides of type A132 and / or crystals of the related type WZBS. The indication that the matrices are thermodynamically two-phase reinforcement reinforced makes it clear that the stored substances cannot be identical to the matrix but through the storage there is at least thermodynamically at least two-phase material regardless of whether a single-phase or multiphase matrix is the basis.

Suitable metallic matrices are low-alloy but also high-alloy steels, preferably transition metals such as Fe, Ni, Co, Cr, Cu, Zn, Ag and / or Sn or alloys thereof. The ceramic matrix of the materials and moldings according to the invention preferably contains carbides such as silicon carbide, boron carbide, titanium carbide, tungsten carbide and other transition metal carbides, borides, in particular transition metal borides such as titanium boride, zirconium boride, tantalum boride or tungsten boron, including mixed crystals and carbides and borides of said compounds, silicides, in particular transition metal silicides such as titanium silicide, molybdenum silicide, iron silicide, nitrides, in particular transition metal nitrides such as boron nitride, aluminum nitride, titanium nitride, titanium carbonitride or nanotalin nitride or vanadium nitride alumina, titanium oxide and / or zirconia.

Particularly well-functioning are in particular deposits containing mixed crystals, of which at least one part of the boron-forming boride is a boride, in particular a diboride of the metals titanium, chromium, zirconium, vanadium, niobium, tantalum, tungsten or molybdenum. Particularly well used are such materials and shaped bodies which, as deposits in the matrix, contain two or more of said borides as mixed crystals. These are preferably mixed crystals with a titanium diboride content, in particular TiB2 / CrB2, TiB2 / VB2, TiB2 / ZrB2, TiB2 / WB2 but also CrB2 / WB2 - mixed crystals.

Examples of the crystals of the type AlB2 of the type AlB2 related to the type W2B5 are in addition to W2B5 itself also Mo2B5 and compounds in which part of tungsten and / or molybdenum is replaced by other transition metals, in particular with Ti or Cr, e.g. Ti) 2B5, (W, Cr) 2B5 or (Mo, W) 2B5.

In order to achieve optimum reinforcement or to avoid spontaneous microcrack growth, it is advantageous to match the thermal expansion coefficients of finely dispersed particles to the matrix. This is made possible primarily by mixed crystal formation of the transition metal borides among themselves. Thus, for example, starting from TiB2, a material with a large anisotropy in the thermal expansion, it is possible to modify the expansion coefficients by alloying CrB2 within wide limits. This is due to the fact that the anisotropy properties of the chromoboride show the inverse sign in relation to TiB2, but both phases are indefinitely miscible with each other above 1,800 ° C and at lower temperatures TiB2 dissolves to a large extent in CrB2. In this way, not only the coefficients of thermal expansion but also the anisotropy contribution can be modified within wide limits. Thus, for example, in a boron carbide matrix or a silicon carbide matrix, by using such mixed crystals radial tensile stresses from about 500 to about 2,500 MPa can be achieved around such storage particles. As further examples may be mentioned the system CrB2- -W2B5 with equally strong solubility of WB2 in CrB2, whereby at constant anisotropy for the thermal expansion its contribution can be modified even more strongly. For example, for a boron carbide matrix and a silicon carbide matrix, the resulting radial tensile stress amounts to between 100 and 2,500 MPa. The invention similarly allows the modulus of elasticity of the storage particles to be altered. It is an advantage if the finely dispersed particles have a higher E-modulus than the matrix. This can advantageously be detected in the TiB2- -W B system. Mixed crystals with an E-modulus of between 500 and 770 GPa can be prepared.

In order to minimize the stresses in the construction, TiB2 / VB2 mixed crystals in particular and for the production of stress-induced microcracks TiB2 / ZrB2 mixed crystals have proven to work well, the latter having the advantage that in mixed ceramic materials containing zirconia with the better compatibility with ZrB2 Zr02 a formation of zirconium titanate occurring at higher temperatures can to a large extent be avoided.

It is advantageous if the deposits in the materials according to the invention, in particular in the case of deposits of the WZB5 type, are disc-shaped. The discs usually have a thickness of 0.05-5 μm, in particular 0.1-1 μm at a length of up to 15 μm, preferably up to 10 μm, the ratio between the thickness and length of the discs being within the range from 5: 100 to 50: 100. Usually these are longer elongated discs with a width: length ratio of preferably 1:10 to 3:10. The beneficial effect will be further elucidated with examples concerning the fracture toughness of a material based on a boron carbide matrix. In comparison with isometric deposits with the same composition, when using disc-shaped deposits, an increase in fracture toughness occurs from 3.2 MPavm to 5-6 MPavm, whereby the strength of the hot-pressed material 800 Mæa did not deteriorate.

The volume concentration of the deposits is generally in the range 10-50% by volume, in particular between 20-40% by volume, calculated on the total volume of deposits and matrix.

Apart from special cases, significantly lower or significantly higher levels of deposits do not lead to any special benefits. Locally deviating concentrations should, however, be taken into account. It is thus known that in the production of material joints, in particular in soldering, welding or sintering of art-like materials, but also of ceramic materials with metals, difficulties often arise with regard to the compatibility between thermal , mechanical or chemical properties of the materials to be joined. If the mentioned properties of the two materials are not sufficiently well matched to each other, mechanical stresses or diffusion and corrosion tendencies can occur, which can weaken the joint or even lead to breakage. Furthermore, due to chemical reactions, the mutual adhesion between the joined materials can be impaired. However, these disadvantages can be circumvented in that the thermal, mechanical or chemical properties of a shaped body according to the invention are changed continuously or stepwise depending on the origin, type and / or amount of storage particles in the shaped body, so that it exhibits the desired properties. at the joining surface. The favorable effect is due to the fact that the design stresses due to thermophysical mismatches do not occur locally in high concentration at the interface but are distributed by only insignificant gradients over a larger volume of the structural part and thus remain uncritical.

The production of the materials and shaped bodies according to the invention can be carried out in such a way that the particles intended for storage and the flowable matrix are mixed with each other and the mixture is then allowed to solidify, whereby a processing may be carried out simultaneously or afterwards or the particles to be stored in the matrix of the material and the shaped body in place.

According to the invention, the preparation can thus be based on pre-reacted fine-grained mixed crystals of transition metal borides of the type AlB2 and / or of fine-grained crystals of the related type WZBS, which are preferably ground down to grain sizes below 10 μm, which are then intimately mixed with corresponding proportions of the, for example, powdered matrix material are subjected to a design and then sintered. 10 15 20 25 30 35, 505 824 Another way is to produce the storage particles in the matrix of the material or shaped body in situ.

In this case, for example during the compression process by sintering, hot pressing or heat isostatic pressing through a reaction between the boron-forming pure components present in stoichiometric amounts or corresponding transition metal carbides with elemental boron or boron carbide, the fine-grained storage particles can be prepared for storage. Also when using the particularly reactive transition metal carbide powders, care must be taken that the addition of powder of elemental boron or boron carbide takes place in stoichiometric amounts. In the case of boron carbide, further care must be taken that carbon formed in the reaction binds. This can be done, for example, with optionally added transition metals, for example titanium, to form the corresponding carbide, or preferably with silicon. Slight excesses of boron or carbon of, for example, 0.1 and 3% by weight are advantageous, whereby these elements in a known manner are able to clean the matrix powder from surface-adhesive oxide layers and are able to achieve a sinter activation.

The storage particles of the AlB2 and / or W2B5 type involved with the liquid matrix can be prepared by reaction, for example heat treatment or reaction sintering, by powder stoichiometrics having corresponding mixtures of the pure components or elements or of transition metal carbides and elements. boron or boron carbide.

The preparation of materials or shaped bodies with a continuously or gradually changing concentration of storage particles can be effected, for example, by powder metallurgical means by stepwise supply of corresponding powder mixtures of the pure borides or their starting compounds or in particular by plasma spraying of transition metal boride powders during the application process. According to the invention, in the case of shaped bodies produced by powder metallurgical means, after the compression carried out by sintering, hot pressing or heat isostatic pressing, a uniform concentration gradient can be set by a homogenization annealing. In the case of plasma spraying, no such finishing is required, since the process provides the thermal energy necessary for the interdiffusion of the transition metal blanks. A corresponding graded setting of thermal, mechanical and chemical properties thus becomes possible according to the invention. It is not only advantageous for joining different materials but also for adapting a shaped body to the building environment's local different environmental conditions. These ambient conditions can consist of gases, liquids (including melts) or solids, which in various ways have a corrosive, oxidative or otherwise reactive effect on the structural part to be reinforced. Examples of this can be electrolyte baths, metal melts, salt melts, hot gases, acidic or alkaline solutions or materials in workpieces, which are processed by contact with a shaped body according to the invention. Methods for intracrystalline precipitation can also be used for the production of materials and shaped bodies according to the invention. Thus, for example, the precipitation of transition metal diboride mixed crystals as well as WZBS-type crystals in species-like matrix according to the invention can take place by an aging storage treatment of transition metal homodiboride mixed crystals pre-homogenized by solution annealing. In this case, the mixed crystal is advantageously produced by diffusion reactions of the weighed-in amounts of the intimately mixed pure transition metal diboride powders. According to the invention, the temperatures for the solution annealing are within a range in which there is an increased mutual solubility of the starting components. This is the case, for example, in the TiB2-CrB2 system, preferably at temperatures above 1,500 ° C, but preferably above 1,800 ° C (unlimited miscibility). In the TiB2-WZBS system, according to the invention, the temperatures for the solution annealing are, for example, above 1,700 ° C, preferably at 2,000-2,200 ° C. In this process, it is irrelevant whether the solution annealing has led to a single-phase material or whether residues of the original starting compounds still remain, if advantageously the majority phase has a mixed crystal which, in relation to the corresponding 10 15 20 25 30 35 e 505 824 second component is as saturated as possible. According to the invention, the precipitation takes place at low temperatures, preferably at temperatures above 1,200 ° C, the choice of temperature and residence time affecting the composition and grain size of the precipitates. The precipitates obtained are usually flat and can show extensions within the nanometer range, eg 2-5 or more to several micrometers, eg to 15 or 50 μm. Small precipitates produced in this way add compressive stresses to the crystal lattice of the host crystal, which results in an increase in hardness. Larger crystallites can even have an increase in toughness if their coefficients of thermal expansion are adapted to the matrix so that the mechanisms influencing the crack path are triggered. In the case of large precipitates, an increase in hardness can also be achieved by selecting the mixed crystal system according to the invention so that the precipitates have lower coefficients of expansion than the value crystal. This is especially the case with tungsten-rich WZBS precipitates in tungsten-poor TiB2 matrix crystals.

In terms of production technology, it can be mentioned that the storage of disc-shaped particles in, for example, powdered matrixes is sometimes cumbersome, since disc-shaped particles in the form of powder are difficult to handle during reprocessing. The separation of individual grain sizes from industrially produced aggregates and the decomposition of particle masses (agglomerates) due to production technology is sometimes very difficult. Furthermore, it is a problem to design such disc mixtures, since often undesired particle orientations, grain size distributions or clumps occur in the untreated body, and which during the sintering process adversely affect the compression in the field of such storage particles (shrinkage difficulty and thus differential sintering). mechanical properties or at least reduces the improving effect of the bearings. Another critical point is the presence of difficult-to-separate larger particles, the diameter of which exceeds the critical grain size for a useful solution. Such particles, which in the case of reprocessing technology, in particular in larger constructions, can only be avoided with difficulty with greater difficulty, have a strength-lowering effect. According to the invention, these problems can be circumvented in that the disk-shaped borides stored here first arise during the compression process ("in situ growth") and thus happen to be oriented, are homogeneously dispersed and their dimensioning can be set within wide limits by the heat treatment. Preferably, tungsten borides, titanium boride, mixed crystals thereof or transition metal borides with WZB5 structure are used. It is possible, for example, to use the forming elements or corresponding element carbides with boron or boron carbide in stoichiometric amounts or the borides. The growth process then takes place by gas phase or liquid phase reactions, whereby preferably the growth in a crystallographic direction is blocked. This can be done, for example, by doping substances, which prevent the nucleation for the construction of the next growth layer, so that this crystal surface only grows laterally. In the transition metal diborides specified according to the invention, this surface is the (0001) surface. Thus, disc-shaped particles are formed with a thickness to length ratio of between 1: 3 and 1: 1,000. Examples of dopants that can be used for disc growth are silicon, aluminum, manganese, iron, cobalt and nickel and mixtures. hence.

The total amount of these impurities required for disk growth amounts to less than 5% by volume, preferably less than 1% by volume, for aluminum, manganese, iron and nickel.

The dopants may be present in the form of impurities in the starting powders of the precursors for the transition metal boride sheets stored here or mixed in finely dispersed form as a powder having a grain size of preferably less than 1 μm during the powder metallurgical work-up or deposited from solutions or organometallic preparticles. In the case of the production of large disks, a silicon melt is preferably required as a means of transport for corresponding atoms or molecules along the surface of the disk to the growing edges. In the case of growth in situ, for example in a ceramic matrix, this is done according to the invention by forming a thin film of melt on the growing particles or by gas phase reactions between vaporized metals or borides thereof. The length of the free-growing transition metal boride sheets can amount to up to 2 or 3 mm at a thickness of 1-10 μm. As a result, the deposits can in particular contain particles with a particle size (length) up to 500 μm. In a ceramic matrix, the diameter growth amounts to up to 30-50 μm at a thickness of from 0.1 up to about 3 μm. Preferably, during the sintering process, discs with a maximum length of less than 10 μm and a thickness of 0.1-1 μm are produced to achieve optimal structural reinforcement. The diameters of the discs can be adjusted for in situ growth using the aging ring temperatures. The actual reaction between, for example, transition metal carbides to borides takes place above 900 ° C, preferably between 900 and 1200 ° C. The slice growth takes place by a diffusion reaction at temperatures up to 1,900 ° C, at which, for example, in a boron carbide matrix or Sic matrix, no grain growth in the matrix can be observed anymore. Preferably, in hot pressing or heat isostatic pressing, the critical reaction temperature is passed relatively quickly, which has a favorable effect on the compression and keeps the sample at temperatures above 1,700 ° C between 10 and 120 minutes.

The materials and moldings according to the invention are characterized by high abrasion resistance, high temperature resistance, high temperature change resistance, high electrical and thermal conductivity even at high temperatures. They can thus be used as cutting tools for processing metallic and non-metallic materials, as electrodes for melt-flow electrolyses even at high temperatures, as motor parts at high temperature change stresses, as high-strength parts for static stress at high temperatures and for parts where high abrasion, erosion and corrosion stresses are present.

The following examples describe the composition of some materials and shaped bodies according to the invention for illustrating the invention and manufacturing methods. Example 15 Preparation and properties of transition metal diboride-mixed crystal particles and their storage in ceramic and metallic matrices Fine-grained TiB2 and fine-grained W2B5 are mixed in a molar ratio of 40:60 to 60:40, eg 50:50, pressed and annealing gas at temperatures of 1,900-2,100 ° C for at least 2-6 hours. This can be done without pressure in a chamber furnace under vacuum or shielding gas or with advantage for simultaneous sintering by hot pressing. By diffusion, single-phase masses consist of grains of a (Ti, W) B2 mixed crystal. The sample is cooled so that the solid state is maintained; in the case of inhomogeneous distribution of the starting powders, a residual content of WZBS may remain, which, however, does not adversely affect the properties of the material.

A (Ti, W) B2 mixed crystal produced in this way has a coefficient of thermal expansion, which at room temperature in the -a direction amounts to about 4 x 10-6K'1 and in the c-direction to about 2 x 10O_6K_1 and is thus lower than in TiB2 and W2B5.

At about 600 ° C, both coefficients of expansion are isotropic.

A mixture of TiB2 and W2B5 in the molar ratio between 70:30 and 80:20, eg 75:25, leads in the same treatment to a coefficient of thermal expansion at room temperature in the a-direction of about 5.5 x 10-6K-1 and in c the direction of about 1 x 10_6K'1.

Isotropy is achieved at about 930 K.

A ternary mixture consisting, for example, of preferably 30.3 mol% TiB2, 23.4 mol% CrB2 and 46.3 mol% W2B5 leads after annealing under the above conditions to a homogeneous mixed crystal with isotropic thermal expansion of about 4.0 x 10-6K-1 at room temperature.

As can be seen from the above, the thermal expansion can be varied in many ways. According to the invention, for the production of the mixed crystals, it is also possible to start from the corresponding stoichiometric mixtures of the elements, from metal carbides and elemental boron or from metal hydrides with elemental boron. The resulting mixed crystals can be comminuted by grinding or in the form of said reacting starting materials mixed with fine-grained ceramic and metallic materials in the required volume ratio, so that the transition diboride mixed crystals form reinforcing particles in a matrix B SiC, Ti Si3, MoSi Fe, Cu or the like. Example 2 Preparation of WZBS precipitates in TiB2 mixed crystal matrix 60 mol% fine-grained TiB2 and 40 mol% fine-grained WZBS (corresponding to 42.8 mol% TiB2 and 57.2 mol% "WB2" ) is intimately mixed and ground by means of an attritor grinder for 30 minutes in an alcoholic suspending agent. The powder mixture is dried, sieved and pressed cold-isostatically below 300-600 MPa into shaped bodies. The shaped bodies are heated in boron nitride crucibles or graphite crucibles with boron nitride coating or overlay in vacuum or argon at 30 K / min to temperatures between 2,100 and 2,250 ° C and kept for 2 hours. Thereby a compression process takes place and the formation of homogeneous (Ti, W) B2-type mixed crystals. The construction will then be single-phase or two-phase, depending on the ratio between weighed-in W2B5 and TiB2.

The maximum solubility of "WB2" in TiB2 is about 63 mol% at 2,250 ° C. At higher amounts of weighted W2B5 or lower aging temperature, a two-phase mass consisting of (Ti, W) B2 mixed crystal and (W-Ti) 2B5 mixed crystal is initially formed, which can also be advantageous. When weighing W2B5, the actual ratio of tungsten to boron must be taken into account. The stoichiometry should preferably be close to 1: 2.0 up to 1; 2.28; In the case of aging, any elemental boron formed by a process of dissolution or excess-forming boron can, for example, be compensated for the formation of B4C by weighing in metallic Ti, TiH2 or W or preferably by TiC, WC or C.

After the aging treatment, the sample is cooled to 1,500-1,900 ° C, whereby the morphology and the sizes of the in situ growing precipitates can be controlled by the cooling rate and the final temperature. At low cooling rates, especially at 5-10 K / min to final temperatures between 1,700 and 1,900 ° C, relatively coarse-grained disc-shaped precipitates of 0.2-0.5 μm thickness and 2-10 μm diameter are obtained. Rapid cooling, preferably at 50-100 K / min to temperatures of 1,500-1,700 ° C, preferably fine precipitates of 0.05- -0.2 μm thickness and 2-10 μm length are obtained. The dimensions of the discs can be affected by the residence time at the final temperature. Thus, residence times at 1,700 ° C for 2 hours give approximately the same disk geometry as a deposition at 1,500 ° C for about 12 hours. In the case of biphasic masses due to an excess of weighted W2B5, these crystallites can also grow further disc-shaped from the edge, so that typical H-shaped shapes are formed, which can also be to the advantage of the mechanical properties.

Example 3 In situ slice growth of W2B5 in B40 matrix 61% by weight of fine-grained WC, 38% by weight of fine-grained B, preferably amorphous and 1% by weight of fine-grained Si are intimately mixed preferably by grinding in a ball mill with cemented carbide balls and isopropanol as dispersant. . In the case of high ball friction, the extra WC portion of the cemented carbide must be taken into account when weighing the B portion. The homogeneous amount of powder is filled after drying in a mold and hot-pressed under vacuum or shielding gas at a piston pressure of in particular 20-60 MPa. At 900-100 ° C, the fine-grained boron metal reacts with WC to WZBS and B4C.

The resulting W2B5 to B4C ratio can be changed by adding B4C or W2B5 in fine grain form to the starting powder. In the first case, B4C may also have participated in the reaction, and which reacted with WC to W2B5 and C, whereby C is again bound to secondary B4C. The fine-grained Si- material predominantly forms a liquid phase, which promotes the compression and the slice growth of the w2B5 phase is accelerated. With continued temperature increase, Si reacts with B40 (B, C, Si) 3 or SiC or dissolves in WZBS and thus no longer exists as a melt. The sample is kept at temperatures between 1,700 and 2,100 ° C for between 10 and 60 minutes.

The reaction forms a very fine structural mass, mainly consisting of a B4C or B12 (B, C, Si) 3 matrix and sheet-shaped WZB5 deposits. The matrix has an average grain size between 0.8 and 2 μm, the WZB5 discs can reach lengths of between 2 and 20 μm and thicknesses between 0.1 and 1 μm. With rising temperature and longer residence time, the dimensions of the discs can be set carefully. For example, at 1,720 ° C and for 10 minutes sintered slices show dimensions of predominantly 0.1 x 1.0 x μm, while a storage for 10 minutes at 2,000 ° C gives slice dimensions of on average 0, 5-0.8 x 3-10 pm. However, it has proved advantageous to set discs with a diameter of between 3 and 5 μm at as small a thickness as possible. The proportion of silicon can in this case preferably be varied between 0 and 5% by weight. A change in the volume fraction of reinforcing disc-shaped W2B5 deposits is obtained by varying the weighted amount of B4C. The tensile strength achieved depends on the ratio of thickness to diameter 1/2. This corresponds to one and the volume fraction of disks at 6-7 MPam 1/2) and a tripling of the value for single-phase B4C (2.4 MPam doubling for a B4C material with non-elongated TiB2 deposits (3.5-4.2 Mæaml). The flexural strength is between 700 and 850 MPa.

Claims (16)

10 15 20 25 30 35 sus 824 M 16 Patentkgav Materials and moldings based on reinforced metallic or ceramic mats, characterized in that they contain fine-grained mixed crystals of transition metal borides of the AIB2 type and / or crystals of the related WZBS type as reinforcement reinforcements. Materials and moldings according to Claim 1, characterized in that they have fine-grained particles of solid solutions of two or more such borides deposited as AlB2-type transition metal borides. Materials and shaped bodies according to Claim 1 or 2, characterized in that those in storage contain Ti-, Cr-, Zr-, Nb-, 2: e-, w- or ne-berianal, especially 'riß2-, crßf , ZrB2, VB2, NbB2, TaB2, WB2 or MoB2 containing mixed crystals or (mixed) crystals which may belong to the WZBS type. Materials and shaped bodies according to one of the preceding claims, characterized in that those deposits contain mixed crystals of at least two borides from the group Ti, Cr, Zr, V, Nb, Ta, W and Mo, preferably of their diborides. Materials and shaped bodies according to one of the preceding claims, characterized in that those deposits contain CrB2 / WB2 mixed crystals or TiB2-containing mixed crystals, in particular TiB2 / CrB2, TiB2 / VB2, TiB2 / ZrB2 and / or TiB2 / WB2 mixed crystals. Materials and moldings according to one of the preceding claims, characterized in that the bearings have a higher E-modulus than the matrix. Materials and shaped bodies according to one of the preceding claims, characterized in that they contain deposits with a particle size of 0.05-500 μm, preferably 0.1-100 μm and in particular 1-50 μm. 10 15 20 25 30 35 17 505 824 Materials and shaped bodies according to one of the preceding claims, characterized in that the bearings of the AlB2 and / or WZB5 type are disc-shaped. Materials and shaped bodies according to claim 8, characterized in that the discs have a thickness of 0.05-5 μm, especially 0.1-1 μm and a length of up to 15 μm and especially up to 10 μm. Materials and shaped bodies according to one of the preceding claims, characterized in that the matrix contains 10-50% by volume, in particular 20-40% by volume of storage particles, calculated on the total volume of the matrix and the storage particles. Process for the production of materials and shaped bodies according to one of the preceding claims, characterized in that fine-grained mixed crystals of transition metal borides of A182 type and / or crystals of the related W2B5 type are mixed into the flowable matrix and that the mixture thereafter, possibly during processing, may solidify. Process for the production of materials and shaped bodies according to one of Claims 1 to 10, characterized in that the fine-grained mixed crystals of transition metal borides of the AIB2 type and / or crystals of the related WZB5 type are formed in place in the matrix. Process for the production of materials and moldings according to Claim 12, characterized in that the storage particles are formed in the powdery matrix, preferably during the solidification process, by their pure, fine-grained forming components or by the fine-grained corresponding transition metal carbides and boron or boron carbide in the corresponding stoichiometry. amounts, possibly with a small excess of boron and boron carbide, respectively. Process for the production of materials and shaped bodies according to one of Claims 1 to 10 and 12, characterized in that the fine-grained storage particles are formed by intracrystalline precipitation after prior homogenization of the storage particles in the matrix by solution annealing and subsequent cooling. Process for the production of materials and shaped bodies according to claim 13, characterized in that for the production of the disc-shaped storage particles the gas phase or liquid phase growth is blocked in a crystallographic direction, preferably by doping with nucleation inhibitors, especially Si, Al, Mn , Fe, Co and / or Ni. Use of materials and moldings according to any one of the preceding claims as and for the production of abrasion and temperature resistant structural parts and elements.