AU2014217875A1

AU2014217875A1 - Metal matrix composite useful as wear parts for cement and mining industries

Info

Publication number: AU2014217875A1
Application number: AU2014217875A
Authority: AU
Inventors: Ufuk BASMACI
Original assignee: AMINCEM S A
Current assignee: AMINCEM SA
Priority date: 2013-02-18
Filing date: 2014-02-13
Publication date: 2015-08-06
Anticipated expiration: 2034-02-13
Also published as: WO2014125034A1; CN105026584B; EP2956561A1; AU2014217875B2; EP2956561B1; CN105026584A; LU92152B1; ZA201505284B

Abstract

The present invention relates to a cast metal matrix composite, a method for the preparation thereof and the uses thereof. In particular, the cast metal matrix according to the present invention comprises -one or more ceramic cakes comprising: Al

Description

WO 2014/125034 PCT/EP2014/052837 1 METAL MATRIX COMPOSITE USEFUL AS WEAR PARTS FOR CEMENT AND MINING INDUSTRIES Technical field [0001] The present invention generally relates to cast metal matrix composites, 5 uses thereof and methods for the preparation thereof. Background Art [0002] Wear parts are used in many industries such as cement and mining industries. The metal matrix composites used as wear parts have to comply with several requirements in order to be efficient. The wear parts are usually 10 implemented within mining equipment intended to crush and grind the solid material. Thus, they have to show a good resistance to the impacts and the abrasion to which they are subjected during their use. Ductile materials show improved resistance to impact but low resistance to abrasion whereas hard abrasion-resistant materials provide a satisfying resistance to abrasion but low 15 resistance to violent impacts. Thus, it is critical to develop a cast metal matrix composite showing a good balance between the resistance to the abrasion and the impacts. Furthermore, the wear parts are consumable materials involving their frequent replacements. It is essential that the replacements of these wear parts be spaced out, easy and cost less. The production costs of the wear parts have to be 20 low for being implemented in the industry. Technical problem [0003] The present invention aims to provide a reinforced cast metal matrix composite useful as wear parts for cement and mining industries. The present invention also intends to provide wear parts showing an extended life service with 25 high production rates while having low production costs. General Description of the Invention [0004] The cast metal matrix composite according to the present invention comprises two distinct parts namely: WO 2014/125034 PCT/EP2014/052837 2 - One or more ceramic cakes comprising: A1 2 0 3 , ZrO 2 , ferrous metal and TiC, - and a metal matrix comprising: ferrous metal and TiC. [0005] It is one aspect of the invention to provide a cast metal matrix composite, 5 which comprises TiC both in the ceramic part and in the metal matrix. [0006] The ceramic cakes correspond to the hard material of the cast metal matrix composite. The ceramic cakes are preformed before being included within the metal matrix. These ceramic cakes show a high hardness due to their composition comprising, in particular, a mixture of TiC and inorganic compounds: A1 2 0 3 and 10 ZrO 2 . [0007] The metal matrix includes a ferrous metal and TiC. The presence of TiC allows reinforcing the matrix of metal. Indeed, the inventors have noted that the reinforcement of the metal matrix with TiC allows obtaining a better resistance of the ceramic cakes within the metal matrix. It means that the ceramic cakes are 15 maintained more strongly within the metal matrix and thus are more hardly removed from it when submitted to the use conditions. Indeed, the presence of TiC within the metal matrix increases its hardness, but does not affect the fracture toughness. The obtained material is thus more wear resistant without increasing the risk for cracking. Furthermore, the inventors surprisingly found out that the 20 insertion of the ceramic compounds (A1 2 0 3 and ZrO 2 ) is improved when the metal matrix also comprises TiC. [0008] Another aspect of the invention concerns the method for the preparation of the cast metal matrix composites. The metal matrix composite according to the present invention is prepared by a casting process. Such a process offers several 25 advantages since it is economical and easy to implement. Furthermore, the formation of TiC within the ceramic cakes occurs during the casting process namely during the pouring step of the metal matrix .The addition of the melt metal matrix upon the ceramic cakes leads to the formation of TiC within the ceramic cakes. Indeed, titanium and carbon are very reactive components and lead to the 30 production of TiC when they are mixed at temperatures above about 1100 C. The particles of TiC obtained show a diameter/size of inferior or equal to about 30 microns. Furthermore, these particles are homogenously distributed within the WO 2014/125034 PCT/EP2014/052837 3 metal matrix. The formation of the TiC particles leads to an increase in strength, strain and hardness of the material obtained, which in turn allows improving its service lifespan and its wear resistance. [0009] In this context, it has to be noted that it would not be possible to add directly 5 this kind of TiC particles (i.e. with the same diameter size) within the metal matrix while benefitting from the same effects. Indeed, even if particles of that size were added, they would coagulate and the metal would not cover them in the way provided by the present method. Such a coagulation and inappropriate covering would be deleterious for the properties of the wear resistant material. 10 [0010] The process of preparation according to the present invention preferably comprises a step of preformation of the ceramic cakes followed by a step of casting a metal matrix. In particular, the method of preparation may thus include the steps of: (a) preparing the ceramic cake(s) by: 15 - mixing A1 2 0 3 , ZrO 2 , FeTi , graphite and a binder, - filling the mixture obtained in preform mold(s), - heating and curing the mixture, - removing the (preformed) ceramic cakes obtained from the preform mold(s), 20 - cooling down the mixture to room temperature, (b) casting the ceramic cake(s) into a composite by: - placing the (preformed) ceramic cakes in resin type mold(s) - closing the resin type mold(s), - melting metal comprising ferrous metal and ferrotitanium 25 and graphite in order to obtain an alloy of metals comprising TiC, - pouring the alloy of metals in the resin type mold(s) - obtaining a cast metal matrix composite. [0011] Another aspect of the invention concerns an article comprising the use of 30 cast metal matrix composites according to the present invention and in particular wear parts.

WO 2014/125034 PCT/EP2014/052837 4 Brief Description of the Drawings [0012] Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which: [0013] Fig. 1 shows a ceramic cake having a honeycomb shape. 5 [0014] Fig. 2 shows a detail of the ceramic cake having a honeycomb shape before pouring the metal matrix. [0015] Fig. 3 shows a view of a cast metal matrix composite according to the present invention wherein ceramic cakes are included within a metal matrix. [0016] Fig. 4 shows portions comprising ceramic cake and a metal matrix in a 10 suitable shape, namely adapted to be inserted within a further metal layer. [0017] Fig.5 shows a specific embodiment of the present invention wherein portions of cast metal matrix composite (such as those of Fig. 4) are included within a further (preferably ductile) metal. Fig.5-A shows this embodiment wherein the portions are visible by transparency within the (preferably ductile) metal. Fig.5 15 B is another view of this embodiment wherein the parts of the portions included within the (preferably ductile) metal are hidden. [0018] Further details and advantages of the present invention will be apparent from the following detailed description of several non limiting embodiments with reference to the attached drawings. 20 Description of Preferred Embodiments [0019] The present invention proposes a cast metal matrix composite which comprises ceramic cakes included within a metal matrix. In particular, this cast metal matrix composite is reinforced by the simultaneous presence of TiC in the ceramic cakes and the metal matrix. 25 [0020] The cast metal matrix according to the present invention comprises: - one or more ceramic cakes comprising: A1 2 0 3 , ZrO 2 , ferrous metal and TiC and - a metal matrix comprising : ferrous metal and TiC.

WO 2014/125034 PCT/EP2014/052837 5 [0021] TiC which is present within the ceramic cakes and the metal matrix is obtained through the following in situ reaction: FeTi+C which converts to Fe+TiC. This reaction is obtained by contacting the reagent materials at high temperatures, namely at temperatures over about 1100C. 5 [0022] It is advantageous to use TiC since it shows a very high hardness value over 3000 HV and is stable in ferrous solutions. [0023] Regarding the ceramic cakes, it has to be noted that the in situ reaction for producing TiC occurs only at the time the metal matrix comprising ferrous metal and TiC is poured onto the ceramic cakes. When pouring the metal matrix, the 10 metal matrix comprising the ferrous metal and TiC infiltrates within the ceramic cakes and fills the gaps between the ceramic grains. Thus, the ceramic cakes are loaded with the metal matrix. This leads to the formation of TiC within the ceramic cakes. As a result, the weight of metal matrix included within the ceramic cake corresponds to four times the weight of the ceramic cake. 15 [0024] Thus, before the pouring step, the (preformed) ceramic cakes comprise: A1 2 0 3 , ZrO 2 , FeTi, graphite and a binder. [0025] A binder is used, within the ceramic cakes, in order to aggregate the grains of ceramic. The binder used in the ceramic cake may be preferably an inorganic binder. In particular, the binder may be selected from the group comprising sodium 20 silicate, colloidal silicate or a mixture thereof. [0026] In particular, it has to be noted that the use of the colloidal silicate reduces the hygroscopic properties of the material obtained and thus avoids the increase of the moisture within the material. Indeed, this is due to the structure of the colloidal silicate which allows binding the sites which could be occupied by the water 25 molecules. Contrary to other binders, the colloidal silicates limit the absorption of water (for example from the ambient air) by the ceramic cakes. Thus, the strength of the ceramic cakes does not decrease which prevents the formation of cracks. In order to limit the effects of water absorption by the binder, the known processes require the use of the ceramic cakes as fast as possible. Such processes do not 30 allow the preformation of large quantities of ceramic cakes since they cannot be stored during a sufficiently long period. As a result, the use of colloidal silicate as a binder represents a preferred embodiment of the present invention with WO 2014/125034 PCT/EP2014/052837 6 significant advantages since a large amount of ceramic cakes can be prepared well before the actual casting of the metal matrix, stored during extended periods and used as needed. [0027] According to a specific embodiment of the present invention, the ceramic 5 cake before the pouring step comprises from 3 to 6 wt% and preferably from 4 to 5 wt% of binder compared to the total weight of the ceramic cake. [0028] Before the pouring step, the quantity of graphite is comprised between 0,2 and 4wt%, preferably from 0,5wt% to 3wt% and preferably from 0,875wt% to 2,625wt% compared to the total weight of the ceramic cake. 10 [0029] Before the pouring step, the ceramic cake comprises 1 to 20 wt% of FeTi and preferably from 5 to 15wt% compared to the total weight of the ceramic cake. [0030] The ceramic cake generally also comprises from 30 to 60 wt% and preferably from 40 to 55 wt% of A1 2 0 3 compared to the total weight of the ceramic cake. 15 [0031] The quantity of ZrO 2 is comprised between 20 and 40 wt% and in particular between 25 and 35 wt% compared to the total weight of the ceramic cake. [0032] According to one embodiment of the present invention, the ceramic cake comprises from 30 to 60wt% of A1 2 0 3 , from 20 to 40wt% of ZrO 2 , from 0,2 to 4wt% of graphite, from 1 to 20wt% of FeTi and from 3 to 6wt% of binder compared to the 20 total weight of ceramic cake before the pouring step. [0033] After the pouring step of the metal matrix, the ceramic cake comprises from 2 to 1 Ovol% of TiC and preferably from 4 to 8vol% of TiC. [0034] The ceramic cakes may have any shape allowing the filling of the metal in the gaps between the ceramic particles, in particular the ceramic cakes may have 25 a honeycomb shape (1) as shown in Fig.1. Indeed, it has been noted that such a shape is particularly suitable for the use according to the present invention. In fact, when casting the metal matrix, the metal can easily and quickly infiltrate each cavity of the ceramic cake (1), whereas without such shape, the metal matrix could solidify before entirely filling the cavities of the ceramic cake. This shape therefore 30 allows a better infiltration of the metal matrix. Fig.2 shows a detailed view of this honeycomb (preform) ceramic cake (1) before pouring the metal matrix, which WO 2014/125034 PCT/EP2014/052837 7 thus comprises A1 2 0 3 , ZrO 2 (corresponding to grains of ceramic (2)), FeTi (3) and graphite (4). [0035] The cast metal matrix composite according to the invention may comprise a plurality of ceramic cakes, wherein the ceramic cakes have a honeycomb shape. 5 [0036] Regarding the metal matrix, it comprises a ferrous metal. Ferrous metals can be defined as metals which comprise a largest part of metal(s) comprising iron (Fe), for example: steels, cast irons and their alloys with other metals. According to one embodiment, the ferrous metals can be selected from: High Chromium Iron (like for example ASTM A532 Class 2 type E), Chromium steel (like for example 10 DIN 1.2601), Ni hard metals (like for example ASTM A532 Class 1 type D) or low alloy steel (like for example DIN 1.2356) and combinations thereof. [0037] The metal matrix includes from 50 to 90 wt% and preferably from 60 to 85 wt% of ferrous metal compared to the total weight of the metal matrix. In addition, the metal matrix also includes TiC. Preferably, TiC is comprised from 0,1 to 10 15 vol%, and in particular from 2 to 6 vol% compared to the total volume of the metal matrix. [0038] The metal matrix may comprise from 50 to 90wt% of ferrous metal compared to the total weight of the metal matrix and from 0,1 to 1 Ovol% of TiC and in particular from 2 to 6 vol% of TiC compared to the total volume of the metal 20 matrix. [0039] According to one embodiment, the cast metal matrix composite comprises from 2 to 10 vol% of TiC, preferably from 4 to 8 vol% TiC, and preferably about 6 vol% TiC with respect to the total volume of metal in the ceramic cake after pouring the metal matrix. It has been identified that wear resistance of ferrous 25 metal casting will be improved by increasing the volume% of TiC up to 6vol%. In fact, a wear resistance peak has been observed at about 6vol% whereas TiC is still homogeneously distributed in ferrous matrix. [0040] Fig.3 shows a cross-section of a cast metal matrix composite (5) according to one embodiment of the present invention. The ceramic cakes (1) are placed in a 30 resin-type mold. A metal matrix (6) has been poured within the ceramic cakes in WO 2014/125034 PCT/EP2014/052837 8 order to fill the resin-type mold. Thus, it is obtained a cast metal matrix composite (5) comprising ceramic cakes (1) embedded within a metal matrix (6). [0041]According to one embodiment of the present invention, the cast metal matrix composite can also comprise an additional metal, in particular a ductile 5 metal. This metal can be selected among the ductile irons. As a result, such cast metal matrix composite would include one ceramic cake and two metals. The ductile metal improves the toughness of the cast metal matrix composite material and allows rendering the material more resistant to shocks and breaking. [0042] The cast metal matrix composite according to the present invention can be 10 used as wear parts for cement and mining industries. [0043] The present invention also concerns an article comprising the cast metal matrix composite according to the present invention such as: wear parts. The wear parts comprising the cast metal matrix composite can be used in general in plants for grinding, crushing and conveying various abrasive materials; in mining and 15 construction equipments such as bucket wheel excavators, dragline excavators, high capacity haulage trucks, and crushing/milling machines; in industries such as cement factories, mines, metallurgy or electricity generating stations. [0044] The article comprising the cast metal matrix composite according to the present invention may also be raw mill, coal mill, grinding mill castings, roller and 20 table segments (or liners) for raw, coal, grinding mills, or crushers or kiln cooler parts. [0045] According to the present invention, the method for producing the cast metal matrix composite includes two main steps. The first one (step (a)) concerns the preparation of the ceramic cakes preforms and the second one (step (b)) relates to 25 the casting of the metal matrix upon the ceramic cakes. [0046] It has to be noted that the second step (b) corresponds to a casting step which is convenient to implement and low-cost. [0047] The preparation of the preformed ceramic cakes (step (a)) includes the steps of: 30 - mixing A1 2 0 3 , ZrO 2 , FeTi, graphite and a binder, WO 2014/125034 PCT/EP2014/052837 9 - filling the mixture obtained in preform molds, - heating and curing the mixture, - removing the (preformed) ceramic cakes from the preform molds. 5 - cooling down the mixture to room temperature, [0048] These steps are performed before the casting of the metal matrix. [0049] According to one embodiment of the present invention: the preform molds are silicone core boxes. Indeed, such kinds of molds, which are very flexible, allow easily removing the ceramic cakes. The preform molds can be in honeycomb 10 shape in order to facilitate the infiltration of the metal matrix when casting. [0050] The heating step of the mixture may be performed with a microwave oven, an infrared oven or a conventional oven, such as a gas or electrical convection oven. [0051] After being cooled at about room temperature (for example below 400C), 15 the ceramic cakes are ready to be subjected to the casting step (or stored until casting is performed). [0052] It has to be noted that when the ceramic cakes comprise colloidal silicate as a binder, the method provides the additional advantage that the ceramic cakes can be prepared well before the casting of the metal matrix. The ceramic cakes can be 20 preformed and stored during one week before being used for the preparation of the cast metal matrix composite. Thus, a large quantity of ceramic cakes can be prepared since they are not subjected to the constraint of being immediately used in the casting process. [0053] The second step (b) of the process concerns casting the ceramic cakes into 25 a composite. [0054] In order to obtain a ceramic metal matrix composite, a metal matrix should be casted/poured upon the ceramic cakes in order to cover and to infiltrate them. [0055] According to one embodiment, the ceramic cakes may be placed e.g. in resin-type molds, such as at the upper surface or the side surface of this resin 30 type mold. The density of the ceramic cake is lower than the density of the metal WO 2014/125034 PCT/EP2014/052837 10 matrix. As a result, when pouring the metal matrix within the resin-type mold, the ceramic cakes are forced to float. During the pouring step, the ceramic cakes are heated up by hot air convection which allows an easy penetration of the metal matrix. 5 [0056] Any appropriate resin-type mold can be used for the preparation of the cast metal matrix composite, such as for example ALpHASET*, furan, sodium silicate or other sand molds. According to one embodiment of the present invention, the ceramic cakes can be screwed to the resin type mold with steel screws or otherwise affixed thereto. 10 [0057] Then, the resin-type mold is closed before pouring the metal matrix. [0058] The metal matrix is prepared by mixing and melting (at least) ferrous metal with ferrotitanium and graphite. This step can be performed in a furnace such as an induction furnace. The ferrotitanium and the carbon should be preferably added within the mixture after the ferrous metal. In particular, the ferrotitanium can be 15 added either into the furnace, in the ladle or directly in the resin-type mold. The advantage to add the ferrotitanium within the furnace is the possibility to use less expensive ferrotitanium which comprises only 30-50 wt% of Ti. Regarding the carbon or graphite, it is preferable to add it directly in the furnace. According to one embodiment of the present invention, the carbon is added in the furnace and 20 the ferrotitanium is added in the ladle. [0059] The pouring step should be performed at a temperature which is 250 to 3000C above the liquidus of the metal. The metal matrix should be poured in the resin-type mold in order to cover and to infiltrate the ceramic cakes and to cover the walls of the resin-type mold. 25 [0060] Additional fettling operations identical to the conventional ones may be implemented. The cast metal matrix composite may for example be subjected to an additional heat treatment. [0061] According to one specific embodiment of the present invention, a further metal can be added to the cast metal matrix composite obtained through the 30 above-mentioned method for improving its resistance to shocks. This metal should be selected among metals more ductile than that used in step (b), for WO 2014/125034 PCT/EP2014/052837 11 example ductile irons. Thus, the method according to the present invention may further comprise an additional step (c) which involves: - placing one or several portion(s) of the cast metal matrix composite obtained from step (b) in a further resin-type 5 mold, - pouring another metal in said resin-type mold. [0062] In order to obtain the portions of the cast metal matrix composite (previously obtained), it may be carved up in suitable shapes. As a result, the cast ceramic metal matrix composite is in the shape of several portions. 10 [0063] Fig.4 shows portions (7) of cast metal matrix composite. These portions (7) are produced in a shape suitable for being included in another metal. As it is shown, these portions comprise the ceramic cakes (1) having a honeycomb shape which are filled with a metal matrix (6). [0064] These portions obtained may be placed in a further resin-type mold for 15 being subjected to a (further) casting step. For this embodiment, this resin-type mold should be heat resistant and could for example comprise sodium silicate. Once placed in the resin-type mold, the portions may be heated up before the pouring step. Then, the additional metal matrix is poured in the resin-type mold upon the portions. As a result, the portions are included within the ductile metal, 20 thereby obtaining a cast metal matrix composite comprising ceramic cakes, a hard wear metal matrix and a ductile shock resistant metal. In fact, the ductile metal constitutes the carrier of the portions of cast metal matrix composites. Fettling operations may be further implemented and a heat treatment may be applied. [0065] Fig.5 A and B illustrate this specific embodiment. Fig.5-A shows this 25 embodiment wherein the portions are visible by transparency within the (preferably ductile) metal whereas in Fig 5-B the parts of the portions which are included within the (preferably ductile) metal are not shown. Fig.5 A and B show portions (7) of cast metal matrix composite which are arranged within another metal (8). These portions (7) have been obtained through steps (a) and (b) of the method 30 described herein. These portions (7) are included within a layer of a further metal (8) which may be for example ductile iron. Thus, the composite obtained according WO 2014/125034 PCT/EP2014/052837 12 to this embodiment (9) comprises both a wear resistant metal matrix composite (7) on the wearing side and shock resistant ductile iron (8) at the carrier side. The portions (7) are preferably spaced in such a way that the cast ductile iron (8) can be infiltrated between these portions. 5 [0066] It is to be noted that all previously mentioned embodiments may be combined where useful or desirable. [0067] The following examples are provided for illustration purposes and should not be construed to limit the invention. a) Examples of compositions of cast metal matrix 10 [0068] The following examples of metal matrixes have been produced by a method according to the present invention. - ASTM A532 Class 1 type D + (0-4 % Titanium + (0,25* %Ti) % Carbon). - ASTM A532 Class 2 type B + (0-4 % Titanium + (0,25* %Ti) 15 % Carbon). - ASTM A532 Class 2 type C + (0-6 % Titanium + (0,25* %Ti) % Carbon). - ASTM A532 Class 2 type D + (0-6 % Titanium + (0,25* %Ti) % Carbon). 20 - ASTM A532 Class 3 type A + (0-4 % Titanium + (0,25* %Ti) % Carbon). [0069] b) Examples of a supplementary (ductile) metal [0070] ASTM A536 80-60-03 (American standard) or ISO 1083 600-3 (International standard) or similar. 25 [0071] c) Example of a cast metal matrix composite - Inside and around the ceramic cake (after the pouring step) - Alumina (A1 2 0 3 ): 1Owt%, - Zirconia (ZrO 2 ): 6 wt %, WO 2014/125034 PCT/EP2014/052837 13 - Titanium Carbide (TiC): 4 wt% (2,65% of TiC coming from metal and 1,35% of it coming from cake, this also corresponds to 6 vol%), - Ferrous Alloy: 80 wt%. 5 - Metal matrix - C: 3,66 wt%, - Si:0,63 wt%, - Mn: 1,3 wt%, - Cr: 18,5 wt%, 10 - Mo: 1,5 wt%, - Cu: 0,8 wt%, - Ni:0, 4 wt%, - Ti: 2,12 wt%. [in fact, 2,12% of Ti is equivalent to 2,65% of TiC (0,53% being C)] 15 [0072] All the cast metal matrix composites according to the present invention show a very good wear resistance. The presence of TiC in both ceramic cakes and metal matrix allows increasing the hardness of the cast metal matrix composites without affecting its fracture toughness. Furthermore, it appears that the ceramic compounds are homogeneously distributed within the metal matrix.

Claims

1. A cast metal matrix composite including: - one or more ceramic cakes comprising: A1 2 0 3 , ZrO 2 , ferrous metal and TiC, and 5 - a metal matrix comprising: ferrous metal and TiC.

2. The cast metal matrix composite according to claim 1 wherein TiC of the ceramic cake(s) and of the metal matrix is produced through an in situ reaction of FeTi+C, which leads to the formation of Fe+TiC.

3. The cast metal matrix composite according to any one of claims 1 to 2 wherein 10 the ferrous metal is High Chromium Iron, Chromium steel, Ni hard metals or low alloy steel.

4. The cast metal matrix composite according to any one of claims 1 to 3 comprising a plurality of ceramic cakes and wherein the ceramic cakes have a honeycomb shape. 15

5. The cast metal matrix composite according to any one of claims 1 to 4 wherein the ceramic cakes comprise from 30 to 60 wt% of A1 2 0 3 , from 20 to 40 wt% of ZrO 2 , from 0,2 to 4 wt% of graphite, from 1 to 20 wt% of FeTi and from 3 to 6 wt% of binder compared to the total weight of the ceramic cakes before pouring the metal matrix. 20

6. The cast metal matrix composite according to any one of claims 1 to 4 which comprises from 2 to 1 Ovol% of TiC after pouring the metal matrix with respect to the total volume of metal in the ceramic cake after pouring the metal matrix.

7. The cast metal matrix composite according to any one of claims 1 to 6 wherein the metal matrix comprises from 50 to 90 wt% of ferrous metal compared to 25 the total weight of the metal matrix and from 0,1 to 10 vol% of TiC and preferably from 2 to 6 vol% of TiC compared to the total volume of the metal matrix.

8. The cast metal matrix composite according to any one of claims 1 to 7 wherein it comprises further metal(s), preferably selected from ductile metals. WO 2014/125034 PCT/EP2014/052837 15

9. An article or apparatus comprising cast metal matrix composite(s) according to any one of claims 1 to 8.

10. Use of a cast metal matrix composite according to any one of claims 1 to 8 or of an article according to claim 9 as wear parts, in particular for cement and 5 mining industries.

11. A method for the preparation of the cast metal matrix composite according to any one of claims 1 to 8 comprising the following steps: (a) preparing ceramic cake(s) by - mixing A1 2 0 3 , ZrO 2 , FeTi, graphite and a binder, 10 - filling the mixture obtained in preform mold(s), - heating and curing the mixture, - removing the ceramic cakes from the preform mold(s), - cooling down the mixture to room temperature, (b) casting the ceramic cake(s) into a composite by 15 - placing the ceramic cake(s) in a resin-type mold, - closing the resin-type mold, - melting metal comprising ferrous metal and ferrotitanium and graphite in order to obtain an alloy of metals comprising TiC, - pouring the alloy of metals in the resin-type mold, 20 - obtaining a cast metal matrix composite.

12. The method according to claim 11 which further comprises an additional step (c) comprising: - placing one or several portion(s) of the cast metal matrix composite obtained from step (b) in a further resin-type mold, 25 - pouring a further metal matrix in the resin-type mold.

13. The method according to claim 12 wherein it comprises a step of: - heating the portion(s) of the cast metal matrix composite in the resin-type mold before the pouring step.

14. The method according to claim 11 or 13 which further comprises the steps of: 30 - implementing fettling operations. WO 2014/125034 PCT/EP2014/052837 16

15. The method according to claim 14 which further comprises the step of: - applying a heat treatment to the cast metal matrix composite obtained.

16. The method according to any one of claims 11 to 15 wherein the preform molds are silicon core boxes. 5

17. The method according to any one of claims 11 to 16 wherein the ceramic cakes are heated in step (a) with a microwave oven, an infrared oven or a conventional oven.

18. The method according to any one of claims 11 to 17 wherein the binder is an inorganic binder, preferably comprising sodium silicate, colloidal silicate or a 10 mixture thereof.