KR20180091865A - METHOD FOR MANUFACTURING METAL MATRIX COMPOSITE COMPRISING INORGANIC PARTICULATES - Google Patents

Abstract

A method of making a porous metal matrix composite is provided. The method includes mixing a metal powder, a plurality of inorganic particles, and a plurality of discontinuous fibers to form a mixture, wherein the metal powder comprises aluminum, magnesium, an aluminum alloy, or a magnesium alloy. The method further comprises sintering the mixture to form a porous metal matrix composite. Typically, the inorganic particles comprise porous particles or ceramic bubbles or glass bubbles, and the inorganic particles and discontinuous fibers are dispersed in the metal. Metal matrix composites have lower density and acceptable yield strength than metals.

Description

METHOD FOR MANUFACTURING METAL MATRIX COMPOSITE COMPRISING INORGANIC PARTICULATES

The present invention relates to a method of making a metal matrix composite comprising a mixture of a metal base and other materials, for example filler materials.

Metallic matrix composites have long been recognized as promising materials because they combine high strength and stiffness with low weight. The metal matrix composite typically comprises a metal matrix reinforced with fibers or other filler materials.

The present invention provides a method of making a lightweight metal matrix composite. There remains a need for a method of forming a metal matrix composite having a lower envelope density than metal while maintaining a certain level of physical properties.

In one aspect, the present invention provides a method of making a porous metal matrix composite. The method includes mixing a metal powder, a plurality of inorganic particles, and a plurality of discontinuous fibers to form a mixture. The method further comprises sintering the mixture to form a porous metal matrix composite. Typically, inorganic particles and discontinuous fibers are dispersed in a metal.

In an exemplary embodiment of the present invention, various unexpected results and advantages are obtained. An advantage of at least one exemplary embodiment of the present invention is that it exhibits both an envelope density lower than metal and an acceptable yield strength (e.g., plastic yielding in tensile stress-strain curves) , A porous metal matrix composite containing inorganic particles dispersed in a metal and discontinuous fibers is produced. Moreover, there is no need to use any coatings on the inorganic particles to provide a metal matrix composite with effectively dispersed inorganic particles in the metal, according to at least some exemplary embodiments of the present invention. The inorganic particles are typically undamaged within the metal matrix composite, having at least some broken particles in at least some exemplary embodiments of the present invention.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following detailed description illustrates exemplary embodiments in more detail. In many places throughout this application, guidance is provided through a list of examples, and these examples may be used in various combinations. In each case, the listed list serves only as a representative group and should not be construed as an exclusive list.

BRIEF DESCRIPTION OF THE DRAWINGS The invention can be more fully understood by considering the following detailed description of various embodiments of the invention in conjunction with the accompanying drawings.
1 is a schematic cross-sectional view of a metal matrix composite made in accordance with an exemplary embodiment of the present invention.
Figure 2 is a graph of stress-strain curves for exemplary matrices and comparative matrices made in accordance with the present invention.
Figure 3 is a graph of stress-strain curves for additional exemplary matrices and comparative matrices.
Figure 4 is a graph of stress-strain curves for additional exemplary matrices and comparative matrices.
Figure 5 is a graph of the stress-strain curves for another exemplary matrix.
Figure 6 is a graph of stress-strain curves for a further exemplary matrix.
Figure 7 is a graph of the stress-strain curves for another exemplary matrix.
Although the foregoing drawings, which may not be drawn to scale, illustrate embodiments of the present invention, other embodiments are also contemplated, as set forth in the Detailed Description for Implementing the Invention.

In the following glossary terms for defined terms, such definitions shall apply to the entire application unless a different definition is provided in the claims or elsewhere in this specification.

Terms

Certain terminology is used throughout this specification and claims, many of which are well known, but which may require some explanation. These terms, as used herein, should be understood as follows.

As used in this specification and the appended claims, the singular forms "a", "an," and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended embodiments, the term "or" is generally used to mean "and / or ", unless the context clearly indicates otherwise.

As used herein, reference to a numerical range by an endpoint includes all numbers contained within that range (e.g., 1 to 5 are 1, 1.5, 2, 2.75, 3, 3.8, 4 and 5).

Unless otherwise indicated, all numbers expressing quantities of ingredients, measurements of properties, etc. used in the specification and embodiments are to be understood as being modified in all instances by the term "about ". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and in the accompanying list of embodiments may vary depending upon the desired properties sought to be obtained by those skilled in the art using the teachings of the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claimed embodiments, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

The term " comprises "and variations thereof are not intended to be limiting insofar as such terms appear in the detailed description and the claims.

The words "preferred" and "preferably" refer to embodiments of the present invention that can provide certain benefits under certain circumstances. However, under the same or other circumstances, other embodiments may also be preferred. Furthermore, reference to one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the present invention.

Reference throughout this specification to "one embodiment", "an embodiment", "one or more embodiments" or "an embodiment" means that the term "exemplary" Means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one of the exemplary exemplary embodiments of the present invention. Thus, the appearances of the phrases "in one or more embodiments," in certain embodiments, "in an embodiment," " in many embodiments, "or & And does not necessarily refer to the same embodiment among the certain exemplary embodiments of the present invention. Furthermore, a particular feature, structure, material, or characteristic may be combined in any suitable manner in one or more embodiments.

The term "dispersed" in reference to one or more fillers in a metal matrix refers to that one or more fillers are distributed throughout the metal matrix to provide a substantially homogeneous metal matrix composite comprising, for example, metal and filler (s) . This is in contrast to having regions of the metal matrix composite (e.g., layers or clusters of filler in the metal matrix composite) having a concentration of one or more fillers that is at least twice that of the regions of the metal matrix composite at different locations to be. Although the filler (s) may be observed in a sufficiently small volume of the metal matrix composite that is not strictly homogeneously distributed in the metal matrix, the filler (s) are still dispersed in the metal.

The term "sinter" refers to the incorporation of the powdered material into solid or porous lumps by heating without complete liquefaction. Optionally, the powdered material is also compacted during sintering.

The term "envelope density" in relation to particles refers to the mass divided by the envelope volume. "Envelope volume" refers to the sum of the volume of solids in each particle and the volume of any voids in the particle. Similarly, the term "envelope density" in relation to a metal matrix composite refers to the mass divided by the envelope volume, where "envelope volume" refers to the volume of solids in the metal matrix composite and the volume of any void in the metal matrix composite ≪ / RTI >

The term "skeletal density" in relation to porous particles refers to the mass divided by the skeletal volume. "Skeletal volume" refers to the sum of the volume of solid material within the particle and the volume of any closed pores.

The term "average true density " in relation to glass bubbles refers to the average density of glass bubbles, rather than the density of a given volume of glass bubbles (depending on the compaction of the glass bubbles in such volume).

The term "plastic yield" refers to the stress when a predetermined amount of permanent deformation of the material occurs.

The term "tensile plastic yielding" refers to the stress when a predetermined amount of permanent deformation of the material occurs while the material is subjected to tensile force.

The term "softening point " refers to the temperature or temperature range at which a material (e.g., solid phase) material begins to slump under its own weight. In the case of a material with a definite melting point (e.g. metal), the softening point is generally regarded as the melting point of the metal or metal alloy. However, for materials that do not have a definite melting point, the softening point may be the temperature at which the elastic behavior of the material changes to a plastic flow. For example, the softening point of glass, glass-ceramic, or porcelain can occur at the glass transition temperature of the material and can be defined by the viscosity of 10 ^7.65 poise. The softening point of the glass is typically measured by, for example, the Vicat method (e.g., ASTM-D1525 or ISO 306) or the Heat Deflection Test (e.g., ASTM-D648) .

The term "uncoated " in the context of a glass bubble refers to the absence of any additional material (i.e., having a different composition than glass) applied to the outer surface of the glass bubble.

The term "yield strength" refers to the stress when plastic elongation of a material is considered to have begun. As used herein, the yield strength is determined at an offset of 0.2%. ASTM B557M-15 discloses: "7.6 Yield Strength - Determination of Yield Strength by Offset Method at Offset of 0.2%". The acceptance or rejection of the material may be determined based on the Extension-Under-Load Method. For the determination test, the offset method shall be used. 7.6.1 Offset test - In order to determine the yield strength by the "offset method", it is necessary to obtain data (autorecording or numerical) which can draw the stress-strain curve. Then, on the stress-strain curve (Fig. 16), locate Om , which is the same as the specified value of the offset, and draw mn parallel to OA to find r , the intersection of mn and the stress-strain diagram. When reporting the value of the yield strength obtained by this method, the specified value of the "offset" used must be noted in parentheses after the term yield strength. Thus: Yield strength (offset = 0.2%) = 360 MPa ".

The term "transition-alumina" refers to any alumina from aluminum hydroxide to alpha-alumina. Specific transition-alumina particles include delta-alumina, eta-alumina, theta-alumina, chi-alumina, kappa-alumina, low-alumina, and gamma-alumina. Transition-alumina particles are generated during the heat treatment of aluminum hydroxide or aluminum oxyhydroxide. The most thermodynamically stable form is usually alpha-alumina.

Various illustrative embodiments of the invention will now be described. The illustrative embodiments of the present invention can make various changes and modifications without departing from the spirit and scope of the invention. It is, therefore, to be understood that the embodiments of the present invention should not be limited to the exemplary embodiments described below but should be determined by the limitations set forth in the claims and any equivalents thereof.

In one aspect, the present invention provides a method of making a porous metal matrix composite. The method includes mixing a metal powder, a plurality of inorganic particles, and a plurality of discontinuous fibers to form a mixture. The method further comprises sintering the mixture to form a porous metal matrix composite.

In some embodiments, the mixing of the metal powder, the inorganic particles, and the discontinuous fibers is performed manually, for example by shaking the container containing the materials by hand. Often shaking is carried out for greater than 15 seconds, greater than 20 seconds, greater than 30 seconds, greater than 45 seconds, or greater than 60 seconds, less than 2 minutes, less than 100 seconds, less than 90 seconds, or less than 70 seconds. When manually mixing the ingredients for the metal matrix composite, the container containing the material is optionally inverted one or more times. In certain embodiments, the mixing of metal powder, inorganic particles, and discontinuous fibers is performed using an acoustic mixer, a mechanical mixer, a shaker table, or a tumbler. Mixing using the device may be similarly performed for greater than 15 seconds, greater than 20 seconds, greater than 30 seconds, greater than 45 seconds, or greater than 60 seconds, less than 2 minutes, less than 100 seconds, less than 90 seconds, or less than 70 seconds . The mixture produced by mixing the components includes inorganic particles and discontinuous fibers dispersed in the metal powder. As discussed above, having inorganic particles and discontinuous fibers dispersed in metal powder provides a substantially homogeneous mixture.

After mixing, the mixture is sintered. In most embodiments, sintering is performed for at least 30 minutes, at least 60 minutes, at least 90 minutes, or at least 2 hours, at least 3 hours, or at most 24 hours; For example from 30 minutes to 3 hours. Typically, the mixture is sintered in a die (e.g., a mold). Sintering is usually carried out in a hot press or furnace at temperatures of 250 ° C or higher, 300 ° C or higher, 400 ° C or higher, 500 ° C or higher, 600 ° C or higher, 1,000 ° C or lower, 900 ° C or lower, Or 700 ° C or less; For example, from 250 캜 to 1,000 캜, or from 400 캜 to 900 캜, or from 600 캜 to 800 캜. In many embodiments, the temperature is increased at a constant rate until the desired maximum temperature is reached.

In some embodiments, the sintering further comprises applying pressure to the mixture in the die. For example, sintering may optionally be at least 4 megapascals (MPa), at least 5 MPa, at least 7 MPa, at least 10 MPa, at least 12 MPa, at least 15 MPa, or at least 20 MPa; 200 MPa or less, 150 MPa or less, 100 MPa or less, 75 MPa or less, 50 MPa or less, or 25 MPa or less; For example from 4 MPa to 200 MPa, from 4 MPa to 50 MPa, or from 15 MPa to 200 MPa. In certain embodiments, the die is flushed with an inert gas (e.g., nitrogen or argon) after release of the applied pressure.

After the sintering process, the metal matrix composite can be allowed to cool (e.g., inside or outside the hot press or furnace). In some embodiments, the metal matrix composite is allowed to cool to room temperature (i.e., the furnace is turned off and the metal matrix composite is allowed to cool itself). In another embodiment, coolant, for example and without limitation, inert gas (e.g., nitrogen, argon, etc.) is passed through a hot press or furnace to allow the metal matrix composite to cool more rapidly.

Referring to Figure 1, a schematic cross-sectional view of a porous metal matrix composite 100 made in accordance with an exemplary embodiment of the present invention is provided. The porous metal matrix composite 100 includes a metal 10, a plurality of inorganic particles 12, and a plurality of discontinuous fibers 14. The inorganic particles 12 and the discontinuous fibers 14 are dispersed in the metal 10. For simplicity, the metal matrix composite is illustrated as having a monolithic shape; The metal matrix composite can be formed into a number of different shapes depending on the intended application. Metallic matrix composites are applicable to industries such as construction, automotive, and electronics where certain metal components can be replaced by metal matrix composites.

In many embodiments, the metal comprises a porous matrix structure. The porous matrix structure is usually obtained from a powdered metal, where the powder comprises a metal structure in which a gas (e.g., air) is incorporated into the solid metal structure. Typically, the metal is present in an amount of at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, or at least 75 wt% of the metal matrix composite; And 95 wt% or less, 90 wt% or less, 85 wt% or less, or 80 wt% or less. In other words, the metal may be present in an amount of 50% to 95% by weight of the metal matrix composite, or 70% to 95% by weight of the metal matrix composite. The metal includes aluminum, magnesium, or an alloy thereof (i.e., an aluminum alloy or a magnesium alloy). Suitable metals include, by way of example and without limitation, aluminum powder having a purity of 99.0% or greater, such as pure aluminum (e. G., Pure aluminum powder available from Eckart, Louisville, KY., Such as AA1100, AA1050, AA1070 Etc); Or an aluminum alloy containing aluminum and 0.2 to 2 mass% of other metals. Such alloys include Al-Cu alloys (such as AA2017), Al-Mg alloys (such as AA5052), Al-Mg-Si alloys (such as AA6061), Al- Or as a mixture of two or more. A variety of suitable metal powders are available from Atlantic Equipment Engineers (Upper Saddle River, NJ).

Typically, when the metal is used in powder form, the metal powder may be at least 300 nanometers (nm), at least 400 nanometers, at least 500 nanometers, at least 750 nanometers, at least 1 micrometer, at least 2 micrometers, at least 5 micrometers At least 7 μm, at least 10 μm, at least 20 μm, at least 35 μm, at least 50 μm, or at least 75 μm; Less than 100 μm, less than 75 μm, less than 50 μm, less than 35 μm, or less than 25 μm. In other words, the metal powder has a range of 300 nm to 100 mu m; Ranging from 1 [mu] m to 100 [mu] m; Or an average particle size in the range of 1 [mu] m to 50 [mu] m. The particle size can be analyzed using, for example, an optical microscope and laser diffraction.

Suitable inorganic particles include particles having a maximum envelope density of less than 2.00 grams per cubic centimeter, less than 1.75 grams per cubic centimeter, less than 1.50 grams per cubic centimeter, less than 1.25 grams per cubic centimeter, or less than 1.00 grams per cubic centimeter. Typically, the plurality of inorganic particles comprises a substantially spherical or acicular shape, but in some embodiments the inorganic particles comprise multicelled bubbles. Particles generally have an aspect ratio of the longest axis to the shortest axis of 2: 1 or less.

Typically, the plurality of inorganic particles is at least 50 nm, at least 250 nm, at least 500 nm, at least 750 nm, at least 1 μm, at least 2 μm, at least 5 μm, at least 7 μm, at least 10 μm, at least 20 μm, Or more, 50 占 퐉 or more, 75 占 퐉 or more, or 100 占 퐉 or more; No more than 5 millimeters (mm), no more than 3 mm, no more than 2 mm, no more than 1 mm, no more than 750 μm, no more than 500 μm, or no more than 250 μm. In other words, the plurality of inorganic particles have a particle size in the range of 50 nm to 5 mm; Ranging from 1 [mu] m to 1 mm; Or an average particle size in the range of 10 [mu] m to 500 [mu] m.

The amount of the inorganic particles dispersed in the metal is not particularly limited. The plurality of inorganic particles is often at least 1% by weight of the metal matrix composite, at least 2%, at least 5%, at least 8%, at least 10%, at least 15%, or at least 20% by weight of the metal matrix composite; Up to 50 weight percent, up to 28 weight percent, up to 26 weight percent, up to 24 weight percent, or up to 22 weight percent of the metal matrix composite. In certain embodiments, the inorganic particles are present in the metal matrix composite in an amount of from 1 wt% to 30 wt%, or from 2 wt% to 25 wt%, or from 2 wt% to 15 wt% of the metal matrix composite. The inclusion of less than 1% by weight of inorganic particles causes the envelope density of the metal matrix composite to be minimized while the inclusion of more than 30% by weight of the inorganic particles results in a metal matrix composite containing an insufficient amount of metal and fiber Which adversely affects the mechanical properties of the matrix composite.

In some embodiments, the plurality of inorganic particles comprises porous particles. As used herein, "porous particle" refers to both agglomerates of non-porous primary particles comprising pores between themselves and pores between at least some of the non-porous primary particles. Examples of useful porous particles include, by way of example and without limitation, porous metal oxide particles, porous metal hydroxide particles, porous metal carbonates, porous carbon particles, porous silica particles, porous dehydrated alumino silicate particles, porous dehydrated metal hydrate particles, zeolite Particles, porous glass particles, expanded pearlite particles, expanded vermiculite particles, porous sodium silicate particles, engineered porous ceramic particles, agglomerates of non-porous primary particles, or combinations thereof. In certain embodiments, the metal of the metal oxide, metal hydroxide, or metal carbonate is selected from aluminum, magnesium, zirconium, calcium, or combinations thereof. In selected embodiments, the porous particles include porous alumina particles, porous carbon particles, porous silica particles, porous aluminum hydroxide particles, or combinations thereof. Porous particles are typically associated with water, and water is usually removed from the porous particles by heating the porous particles. Optionally, the porous particles comprise transition-alumina particles. Suitable porous particles include, for example and without limitation, Versal 250 boehmite powder available from UOP LLC, Des Plaines, Ill., Chiba Ink Chemical Company Limited A YH-D 16 boehmite powder available from Zibo Yinghe Chemical Company, Ltd., Shandong, China, and Alumax PB300 boehmite available from PIDC International (Ann Arbor, Mich. .

In some embodiments, the plurality of inorganic particles include ceramic bubbles or glass bubbles. Suitable materials for ceramic bubbles and glass bubbles include, by way of example and without limitation, alumina, aluminosilicates, silicas, or combinations thereof. Glass bubbles that may be purchased include, for example, LightStar, EconoStar, and High Alumina Sensophier, available from Cenostar Corporation of Amesbury, Mass. do. Preferably, ceramic bubbles and glass bubbles are not coated (e.g. with a metal material that has been used to assist wetting of the bubble by a metal matrix).

In embodiments where the metal has a high melting point (e. G., Aluminum) and the inorganic particles are glass bubbles, a plurality of (e. G., Uncoated) glass bubbles are advantageously & Includes glass to withstand heating to temperature. The use of an intrinsic high temperature glass bubble allows its incorporation into the metallic matrix composite; otherwise the metallic matrix composite can be formed by softening a glass bubble, for example by softening at least a portion of the glass bubble to the point where the glass bubble is deformed and / Lt; RTI ID = 0.0 > and / or < / RTI >

One suitable type of glass bubble includes a bubble leaching less than 100 micrograms of sodium ions per gram of glass bubble in deionized water with stirring for 2 hours with deionized water. An advantage of such a glass bubble with a low sodium leaching rate is that leaching of sodium ions is often useful in electronic applications where this is not acceptable. In one embodiment, suitable compounds for use in making such low sodium glass bubbles include silica, lime, boric acid, calcium phosphate, calcined alumina silicate, and magnesium silicate. In certain embodiments, such low sodium glass bubbles exhibit a softening temperature of 717 캜 to 735 캜, as measured by thermal dilatometry.

Preferably, the inorganic particles comprise uncoated inorganic particles. Advantageously, the use of uncoated inorganic particles provides a reduction in material cost and coating time. The method according to at least some embodiments of the present invention produces a porous metal matrix composite in which inorganic particles are dispersed in the metal without requiring any additional material to improve contact between the inorganic particles and the metal.

The plurality of discontinuous fibers dispersed in the metal matrix composite are not particularly limited and include, for example, inorganic fibers such as glass, alumina, aluminosilicate, carbon, basalt, or a combination thereof. More particularly, in certain embodiments, the fibers comprise at least one metal oxide, alumina, alumina-silica, or combinations thereof. Discrete fibers have an average length of less than 5 centimeters, which tends to be more beneficial to dispersion in the metal matrix than longer fibers. In many embodiments, the fibers have an average length that is shorter than the minimum dimension of the mold or die used to form the metal matrix composite, so that the orientation of the fibers is not limited by the mold or die. Often, the ratio of the length of the fiber to the minimum dimension of the mold or die is less than 1: 1. In some embodiments, the discrete fibers have an average length of less than 4 centimeters, less than 3 centimeters, or less than 2 centimeters. The discontinuous fibers can be formed from continuous fibers by methods known in the art, such as, for example, chopping and milling. Typically, the plurality of discontinuous fibers comprise an aspect ratio of at least 10: 1.

Suitable discontinuous fibers may have a variety of compositions such as ceramic fibers. The ceramic fibers can be produced in continuous length, which is chopped or sheared as discussed herein to provide the ceramic fibers of the present invention. Ceramic fibers can be produced from a variety of commercially available ceramic filaments. Examples of filaments useful for forming ceramic fibers include ceramic oxide fibers sold under the trade designation NEXTEL (3M Company, St. Paul, Minn.). Nextel is a continuous filament ceramic oxide fiber with low elongation and shrinkage at operating temperatures and provides good chemical resistance, low thermal conductivity, thermal shock resistance, and low porosity. Specific examples of Nextel fibers include Nextel 312, Nextel 440, Nextel 550, Nextel 610, and Nextel 720. Nextel 312 and Nextel 440 are refractory aluminoborosilicates comprising Al ₂ O ₃ , SiO ₂ and B ₂ O ₃ . Nextel 550 and Nextel 720 are aluminosilica and Nextel 610 is alumina. During manufacture, the Nextel filaments are coated with an organic sizing or finish that serves as an aid in textile processing. Sizing may include the use of other organic components applied to starch, oil, wax or filament strands for protection and handling aids. The sizing can be removed from the ceramic filaments by heating the filaments or ceramic fibers to a temperature of 700 DEG C for 1 to 4 hours.

The ceramic fibers can be cut or chopped to provide a relatively uniform length, which can be achieved by cutting the continuous filaments of the ceramic material in a mechanical shearing operation or in a laser cutting operation, among other cutting operations. Given the highly controlled properties of such a cutting operation, the size distribution of the ceramic fibers is very narrow and makes it possible to control the composite properties.

The length of the ceramic fiber was measured with an optical microscope (Olympus MX61, Japan) equipped with a CCD camera (Olympus DP72, Tokyo, Japan) and analysis software (Olympus Stream Essentials, Tokyo). ≪ / RTI > Samples can be prepared by spreading a representative sample of ceramic fibers on a glass slide and measuring the length of more than 200 ceramic fibers at 10X magnification.

Suitable fibers include, for example, ceramic fibers available under the trade designation Nextel (available from 3M Company, St. Paul, Minn.), Such as Nextel 312, 440, 610 and 720. One presently preferred ceramic fiber comprises polycrystalline alpha -Al ₂ O ₃ . Suitable alumina fibers are described, for example, in U.S. Patent No. 4,954,462 (Wood et al.) And U.S. Patent No. 5,185,299 (Wood et al.). Exemplary alpha alumina fibers are commercially available under the trade designation Nextel 610 (3M Company, St. Paul, Minnesota, USA). In some embodiments, the alumina fibers are polycrystalline alpha-alumina fibers and comprise, based on the theoretical oxides, greater than 99 wt% Al ₂ O ₃ and 0.2 to 0.5 wt% SiO ₂ , based on the total weight of the alumina fibers do. In another embodiment, some preferred polycrystalline alpha-alumina fibers include alpha alumina having an average grain size of less than 1 [mu] m (or, in some embodiments, even less than 0.5 [mu] m). In some embodiments, the polycrystalline alpha-alumina fibers have an average tensile strength of at least 1.6 GPa (in some embodiments, at least 2.1 GPa, or even at least 2.8 GPa). Suitable aluminosilicate fibers are described, for example, in U.S. Patent No. 4,047,965 (Karst et al.). Exemplary aluminosilicate fibers are marketed under the trade names NEXTEL 440 and NEXTEL 720 by the 3M Company (St. Paul, Minn.). Aluminoborosilicate fibers are described, for example, in U.S. Patent No. 3,795,524 (Sowman). Exemplary aluminoborosilicate fibers are sold under the trade designation Nextel 312 by 3M Company. Boron nitride fibers can be prepared, for example, as described in U.S. Patent No. 3,429,722 (Economy) and 5,780,154 (Okano et al.).

The ceramic fibers may also be formed from other suitable ceramic oxide filaments. Examples of such ceramic oxide filaments include those available from Central Glass Fiber Co., Ltd. (e.g., EFH75-01, EFH150-31). Aluminoborosilicate glass fibers (i.e., "E-glass" fibers) containing less than about 2% alkali or substantially free of alkali are also preferred. E-glass fibers are available from numerous commercial sources.

The amount of the discontinuous fiber dispersed in the metal matrix composite is not particularly limited. The plurality of fibers is often at least 1 weight percent of the metal matrix composite, at least 2 weight percent, at least 3 weight percent, at least 5 weight percent, at least 10 weight percent, at least 15 weight percent, at least 20 weight percent, or at least 25 weight percent of the metal matrix composite Wt% or more; Up to 50 weight percent, up to 45 weight percent, up to 40 weight percent, or up to 35 weight percent of the metal matrix composite. In certain embodiments, the fibers are present in the metal matrix composite in an amount of 1 wt% to 50 wt%, or 2 wt% to 25 wt%, or 5 wt% to 15 wt% of the metal matrix composite. The inclusion of less than 1% by weight of fibers results in a minimum increase in the strength of the metal matrix composite, while the inclusion of fibers in excess of 50% by weight results in the formation of metal matrix composites due to metal matrix composites containing insufficient amounts of metal and inorganic particles. Lt; RTI ID = 0.0 > density. ≪ / RTI > In some embodiments, the plurality of inorganic particles and the plurality of discontinuous fibers together are present in an amount of 5% to 50% by weight of the metal matrix composite.

Advantageously, the metal matrix composite exhibits both reduced envelope density (as compared to pure metal) and acceptable mechanical properties. For example, metal matrix composites typically have an envelope density of 1.35 to 2.70 grams per cubic centimeter or 1.80 to 2.50 grams per cubic centimeter. For example, the metal matrix composite may have a thickness of at least 1.60 grams per cubic centimeter, at least 1.75 grams per cubic centimeter, at least 1.90 grams per cubic centimeter, at least 2.00 grams per cubic centimeter, at least 2.10 grams per cubic centimeter, or at least 2.25 grams per cubic centimeter Envelope density; And an envelope density of less than 2.70 grams per cubic centimeter, less than 2.60 grams per cubic centimeter, less than 2.50 grams per cubic centimeter, less than 2.40 grams per cubic centimeter, or less than 2.30 grams per cubic centimeter.

In some embodiments, the metal comprises aluminum or an alloy thereof, and the metal matrix composite has an envelope density of from 1.80 to 2.50 grams per cubic centimeter; 2.00 to 2.30 grams per cubic centimeter; Or from 1.80 to 2.20 grams per cubic centimeter.

In certain embodiments, the metal comprises magnesium or an alloy thereof, and the metal matrix composite has an envelope density of 1.35 to 1.60 grams per cubic centimeter; 1.55 to 1.60 grams per cubic centimeter; Or 1.35 to 1.50 grams / cubic centimeter.

Advantageously, in many embodiments, the metal matrix composite comprises an envelope that is at least 8% lower (or 10% or more lower, 12% or higher, 15% or lower, or 17% or lower) Density and can withstand 1% strain before fracture. This combination of properties not only provides a lighter weight of metal but also maintains some metallic characteristics of the metal matrix composite. In particular, the metal matrix composite preferably exhibits a yield strength before fracture in a tensile test. In certain embodiments, the metal matrix composite has a yield strength of at least 50 megapascals, at least 75 megapascals, at least 100 megapascals, at least 150 megapascals, or at least 200 megapascals.

The metal matrix composites of at least some exemplary embodiments of the present invention exhibit stress-strain curves exhibiting plastic yield strength behavior and the metal matrix composites of at least certain exemplary embodiments of the present invention exhibit tensile plastic deformation behavior stress- Curves. That is, the stress-strain curve represents the area of the plastic flow. The plastic yield curve and the tensile plastic yield curve are in contrast to the pure brittle fracture mechanism. That is, pure embrittleness behavior represents only the elastic region within the stress-strain curve, and does not represent the (at all) regions of the plastic flow. Surprisingly, the combination of both inorganic particles and discontinuous fibers as fillers in metal matrix composites according to at least some embodiments of the present invention provided plastic yield curve and / or tensile plastic yielding behavior in testing. For example, referring to FIG. 3, the stress-strain curves for Example 13 containing both fibers (described in detail below) and both porous inorganic particles exhibit yielding prior to the brittle fracture mechanism. In certain embodiments, the metal matrix composite can withstand strains of 1%, 1.5%, or 2% before fracture. Furthermore, it was not expected that the metal powder would remain in the porous inorganic particles after being squeezed into the pores of the porous inorganic particles during sintering (especially sintering under the applied pressure), but not separated from the porous inorganic particles. Interestingly, the porous inorganic particles also did not tend to be damaged (e.g., crumble or crush) during sintering, rather maintaining its porous framework structure.

In many embodiments, the metal matrix composite may have a density of at least 25 megapascals (MPa), such as at least 40 MPa, at least 50 MPa, at least 75 MPa, at least 100 MPa, at least 150 MPa, at least 200 MPa, at least 250 MPa, MPa < / RTI > Additionally, it may be useful to consider the tensile strength of the metal matrix composite as the tensile strength of the metal matrix composite is related to the envelope density of the metal matrix composite, typically because tensile strength is sacrificed during lightening of the composite. In some embodiments, the metal matrix composite has an envelope density of from 1.80 to 2.50 grams per cubic centimeter and a maximum tensile strength of at least 50 MPa, at least 100 MPa, at least 150 MPa, at least 200 MPa, at least 250 MPa, or at least 300 MPa.

Advantageously, in certain embodiments, desirable mechanical properties are obtained without the need for fillers other than inorganic particles and discontinuous fibers. In such an embodiment, the metal matrix composite consists essentially of a metal, a plurality of inorganic particles, and a plurality of discrete fibers. Thus, the metal matrix composite may additionally contain additives that do not substantially affect the mechanical properties of the metal matrix composite. In contrast, metal matrix composites consisting essentially of a metal, a plurality of inorganic particles, and a plurality of discrete fibers may not further include additives such as materials used to assist in dispersing the filler.

The metal matrix composites according to aspects of the present invention can be manufactured by hot pressing, powder extrusion, hot rolling, hot rolling after hot rolling, cold compaction and sintering, hot isostatic pressing, May be prepared according to various suitable methods known to those skilled in the art, including the same powder metallurgy process. In one embodiment, the metal matrix composite is produced by dispersing inorganic particles and discontinuous fibers in a metal powder by mixing a metal powder, a plurality of inorganic particles, and a plurality of discontinuous fibers, and then sintering the mixture to form a metal matrix composite . For example, such a powder metallurgy process is described in detail in Example 1 below.

Exemplary embodiments

Embodiment 1 is a method for producing a porous metal matrix composite material. The method includes mixing a metal powder, a plurality of inorganic particles, and a plurality of discontinuous fibers to form a mixture. The method further comprises sintering the mixture to form a porous metal matrix composite.

Embodiment 2 is the method of Embodiment 1, wherein the mixture is sintered in a die.

Embodiment 3 is a method according to Embodiment 1 or Embodiment 2, and sintering is performed at a temperature of 250 ° C to 1,000 ° C.

Embodiment 4 is a method of any of Embodiments 1 to 3, wherein sintering includes an applied pressure.

Embodiment 5 is the method of Embodiment 4, wherein sintering is performed at a pressure of 4 megapascals to 200 megapascals.

Embodiment 6 is a method of any of Embodiments 1 to 5, wherein sintering is performed for a time of 30 minutes to 3 hours.

Embodiment 7 is a method of any of Embodiments 1 to 6, wherein mixing is performed using an acoustic mixer, a mechanical mixer, or a tumbler.

Embodiment 8 is a method of any of Embodiments 1 to 7, wherein the mixture includes inorganic particles and discontinuous fibers dispersed in a metal powder.

Embodiment 9 is a method of any of Embodiments 1 through 8 wherein the metal matrix composite has an envelope density that is at least 8% lower than the density of the metal and is capable of withstanding a strain of 1% before fracture.

Embodiment 10 is the method of Embodiment 9, wherein the metal matrix composite can withstand a strain of 2% before fracture.

Embodiment 11 is a method according to any one of Embodiment 1 to Embodiment 10, wherein the metal matrix composite has a yield strength of 50 mega pascals or more.

Embodiment 12 is a method according to any one of Embodiment 1 to Embodiment 11, wherein the metal matrix composite has a yield strength of 100 megapascals or more.

Embodiment 13 is a method according to any one of Embodiments 1 to 12, wherein the metal matrix composite has a maximum tensile strength of 100 mega pascals or more.

Embodiment 14 is a method according to any one of Embodiment 1 to Embodiment 13, wherein the metal matrix composite has a maximum tensile strength of 200 mega pascals or more.

Embodiment 15 is a method according to any one of Embodiment 1 to Embodiment 14, wherein the metal matrix composite has a maximum tensile strength of 300 mega pascals or more.

Embodiment 16 is a method according to any one of Embodiment 1 to Embodiment 15, wherein the plurality of inorganic particles includes porous particles.

Embodiment 17 is the method of Embodiment 16, wherein the porous particles have a maximum envelope density of 2 grams / cubic centimeter or less.

Embodiment 18 is the method of Embodiment 15 or Embodiment 16, wherein the porous particles are selected from the group consisting of porous metal oxide particles, porous metal hydroxide particles, porous metal carbonate, porous carbon particles, porous silica particles, porous dehydrated aluminosilicate particles, Hydrated particles, zeolite particles, porous glass particles, expanded pearlite particles, expanded vermiculite particles, porous sodium silicate particles, engineered porous ceramic particles, agglomerates of non-porous primary particles, or combinations thereof.

Embodiment 19: A method of any of embodiments 16-18, wherein the porous particles comprise porous alumina particles, porous carbon particles, porous silica particles, porous aluminum hydroxide particles, or combinations thereof.

Embodiment 20 is the method of Embodiment 19, wherein the porous particles comprise transition-alumina particles.

Embodiment 21 is a method according to any one of Embodiments 1 to 15, wherein the plurality of inorganic particles include a ceramic bubble or a glass bubble.

Embodiment 22: The method of Embodiment 21, wherein the glass bubble includes glass which is resistant to heating to a temperature of 700 占 폚 for 2 hours or more without softening.

Embodiment 23 is the method of Embodiment 21 or 22 wherein the glass bubble leaches less than 100 micrograms of sodium ions per gram of glass bubble in deionized water with stirring for 2 hours with deionized water.

Embodiment 24 is a method according to any one of Embodiment 1 to Embodiment 23, wherein the plurality of inorganic particles has a maximum envelope density of 2 grams / cubic centimeter or less.

Embodiment 25 is a method according to any of Embodiment 21 to Embodiment 23, wherein the plurality of inorganic particles includes alumina, aluminosilicate, silica, or a combination thereof.

Embodiment 26 is a method according to any of Embodiment 18 to Embodiment 21, Embodiment 24 or Embodiment 25, wherein the inorganic particles include multi-cell type bubbles.

Embodiment 27 is a method according to any of Embodiments 1 to 26, wherein the plurality of inorganic particles have a substantially spherical shape or an acicular shape.

Embodiment 28 is a method according to any of Embodiments 1 to 27, wherein the plurality of inorganic particles have an average particle size in the range of 50 nm to 5 mm.

Embodiment 29 is a method according to any one of Embodiment 1 to Embodiment 28, wherein the plurality of inorganic particles have an average particle size in a range of 1 占 퐉 to 1 mm.

Embodiment 30 is a method according to any of Embodiments 1 to 29, wherein the plurality of inorganic particles have an average particle size in a range of 10 μm to 500 μm.

Embodiment 31 is a method of any of Embodiments 1 to 30 wherein the plurality of discontinuous fibers comprise glass, alumina, aluminosilicate, carbon, basalt, or combinations thereof.

Embodiment 32 is a method according to any of Embodiments 1 to 31, wherein the plurality of discontinuous fibers have an aspect ratio of 10: 1 or more.

Embodiment 33 is a method of any of Embodiments 1 to 32 wherein the metal comprises a porous matrix structure.

Embodiment 34 is a method according to any one of Embodiment 1 to Embodiment 33, wherein the metal includes aluminum or an alloy thereof.

Embodiment 35. The method of any one of embodiments 1 to 34 wherein the metal matrix composite has an envelope density of from 1.80 to 2.50 grams per cubic centimeter.

Embodiment 36. The method of any one of embodiments 1 to 34 wherein the metal matrix composite has an envelope density of from 2.00 to 2.30 grams per cubic centimeter.

Embodiment 37. A method as in any of embodiments 1 to 34 wherein the metal matrix composite has an envelope density of from 1.80 to 2.20 grams per cubic centimeter.

Embodiment 38 is a method according to any one of Embodiments 1 to 33, wherein the metal includes magnesium or an alloy thereof.

Embodiment 39. The method of embodiment 38 wherein the metal matrix composite has an envelope density of 1.35 to 1.60 grams / cubic centimeter.

Embodiment 40 is the method of Embodiment 38 or 39 wherein the metal matrix composite has an envelope density of from 1.55 to 1.60 grams per cubic centimeter.

Embodiment 41 is the method of Embodiment 38 or Embodiment 39, wherein the metal matrix composite has an envelope density of 1.35 to 1.50 grams / cubic centimeter.

Embodiment 42 is a method of any of Embodiments 1 to 41 wherein the metal matrix composite exhibits a yield strength before fracture in a tensile test.

Embodiment 43 is the method of any of Embodiments 1 to 42 wherein the metal is present in an amount of from 50% to 95% by weight of the metal matrix composite.

Embodiment 44. The method as in any of Embodiments 1 to 43, wherein the plurality of inorganic particles is present in an amount of 2 to 50% by weight of the metal matrix composite.

Embodiment 45. A method as in any of embodiments 1 to 44 wherein the plurality of discontinuous fibers are present in an amount of from 2% to 25% by weight of the metal matrix composite.

Embodiment 46. The method according to any of Embodiments 1 to 45 wherein the plurality of inorganic particles and the plurality of discontinuous fibers are present in an amount of 5 to 50% by weight of the metal matrix composite.

Embodiment 47 is a method according to any of Embodiments 1 to 46 wherein the envelope density of the inorganic particles is at least 40% lower than the density of the metal.

Embodiment 48. The method of any of embodiments 1 to 47 wherein the envelope density of the inorganic particles is at least 50% lower than the density of the metal.

Embodiment 49. A method as in any of Embodiments 1 to 48, wherein the metal matrix composite is a metal; A plurality of inorganic particles; And a plurality of discontinuous fibers.

Example

These embodiments are for illustrative purposes only and are not intended to be limiting in any way to the scope of the appended claims. Notwithstanding that the numerical ranges and parameters describing the broad scope of the invention are approximations, the numerical values set forth in the specific embodiments are recorded as precisely as possible. However, any numerical value inherently includes a certain error inherently resulting from the standard deviation found in its respective test measurement. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Summary of Materials

Unless otherwise stated, all parts, percentages, ratios, etc. in the remainder of the examples and specification are by weight. Table 1 provides a description and source of materials used in the following examples:

[Table 1]

Test method 1. Three point bending test

Three point bending test was used to determine the stress and strain of the metal matrix composites. In the three-point bending test, samples were longitudinally placed between two cylindrical supports spaced by 32 mm. A third loading cylinder suspended from the load cell of the test apparatus was lowered at its midpoint to touch the sample. Software provided by MTS Systems Corporation, Eden Prairie, Minn., USA, equipped with a 100 kilo Newton (KN) load cell - load at the center of the sample through the intermediate loading cylinder using a controlled load frame Were added. The system measured the force applied to the sample and the displacement of the intermediate loading cylinder from its starting position for each time point. These values were converted to stress and strain, respectively, using standard force equations.

Test method 2. Acoustic dispersion method

To homogeneously disperse one or more filler materials in the metal, all materials were poured into 50 milliliter (mL) glass vials and then tightly capped. Next, the vials were loaded into a Resodyn LabRAM acoustic mixer (Resodyn Corporation, Bute, MT) and shaken at 70% intensity for 3 minutes using automatic frequency control, It was patted 3 to 5 times on the surface so that all the material was submerged in the bottom of the vial.

Test method 3. Ion leaching test

A sample of 100 g of glass bubbles was stirred with 1000 g of deionized water (DI water) in an ultrasonicator for approximately 2 hours. The glass bubble was then separated from the DI water by centrifugation at 10,000 revolutions per minute (rpm) for 10 minutes. The ion concentration in the resulting leach solution was measured by ion chromatography. The area of each ion in the standard versus the concentration of that ion in the standard was plotted to provide a separate calibration curve for each ion. The measured area of each ion was used to determine the concentration of each ion leached from the sample. Only each ion was identified by retention matching.

Test method 4. Manual dispersion method

To manually disperse one or more filler materials in the metal, all materials were poured into 50 milliliter (mL) glass vials and then capped tightly. Next, the vial was shaken by hand for 30 seconds and patted 3 to 5 times against the hard surface to allow all the material to sink to the bottom of the vial.

Production Example 1

Each of the materials listed in Table 2 below was mixed and placed in a fused silica crucible. The mixture was then heated in a furnace at 2320 DEG F (1271 DEG C) for 4 hours. Next, the material was cooled to room temperature (e.g., about 23 占 폚). The material was poured out of the crucible and crushed into frit particles by a disk mill (BICO Inc., Burbank, CA). The maximum size of the frit was less than 5 mm. The frit particles were then jet-milled into powder having a particle size mass-median-diameter (D50) of 20 占 퐉 using a jet mill (Hosokawa Alpine, Augsburg, Germany). 1000 g of powder were then mixed with 1100 g of water, each with 2% by weight of additional boric acid based on the total weight of the glass powder, and 0.3% by weight of sulfur from zinc sulfate as well as 1% by weight of CMC. The total solids of the slurry were made up to 48% by weight. The water / frit powder slurry was milled with a LabStar mill (NETZSCH Premier Technologies, LLC, Exton, Pennsylvania) with a D50 of 1.4 μm primary particle size. The slurry from the mill was spray dried to form agglomerated feed particles. A glass bubble was produced from the spray dried feed through a natural gas flame. The total glass bubble density and flame conditions were as listed in Table 3 below. The resulting bubbles were D5 of 7 占 퐉, D50 of 35 占 퐉, and D90 of 60 占 퐉.

[Table 2]

[Table 3]

[Table 4]

Example 1 (Comparative Example, CE-1)

10 grams (g) of Al 1-511 powder was poured into a circular graphite die having an internal diameter of 1.5 inches (3.81 centimeters). The Al 1-511 powder was sintered as follows: the die was loaded into an HP 50-7010 hot press (Thermal Technology LLC, Santa Rosa, Calif., USA) and the setup pumped down to vacuum Respectively. The die was heated from room temperature to 25O < 0 > C / minute ([deg.] C / min) to 600 [deg.] C and held there for 15 minutes. After maintaining the temperature for 15 minutes, a force of 640 kilograms (kg) (800 pounds per square inch of pressure for this size die) was applied at 600 DEG C for 1 hour (hr). The pressure was then released, the chamber was flooded with nitrogen, and the die was again allowed to cool to room temperature. The bulk density of 1.91 grams per cubic centimeter (g / cc) was calculated by measuring the mass as well as the dimensions of the resulting sintered disc, which was 29% lower than that of pure dense pure aluminum. Strips approximately 0.5 inches (1.27 centimeters) wide and 1.5 inches (3.81 centimeters) wide were cut from the middle of the disc and subjected to the three-point bending test described above. The sample had a maximum tensile strength of 31 megapascals (MPa), a ratio of strength to density of 16. The results are shown in Table 5 below.

Example 2 (Comparative Example, CE-2)

10 g of Al 1-511 powder and 1 g of glass bubble were mixed by the passive dispersion method described above and the mixture was poured into the same graphite die as in Comparative Example 1. [ The setup was then subjected to the same sintering procedure as described in Comparative Example 1 above. The resulting sintered disc had a density of 1.58 g / cc. The results of the three-point bending test are shown in Table 5 and FIG.

Example 3 (Comparative Example, CE-3)

10 g of Al 1-511 powder and 1 g of ceramic fiber were mixed by the manual dispersion method described above and the mixture was poured into the same graphite die as in Comparative Example 1 and Comparative Example 2. The setup was then subjected to the same sintering procedure as described in Comparative Example 1 above. The resulting disc had a density of 2.11 g / cc. The results of the three-point bending test are shown in Table 5 and FIG.

Example 4 (Comparative Example, CE-4)

9 g of Al 1-511 powder, 0.3 g of glass bubble, and 1.7 g of ceramic fiber were gently agitated and the mixture was poured into the same graphite die as in Comparative Examples 1 to 3. The setup was then subjected to the same sintering procedure as described in Comparative Example 1 above. The resulting disc had a density of 1.72 g / cc. The results of the three-point bending test are shown in Table 5 and FIG.

Example 5 (EX-5)

9 g of Al 1-511 powder, 0.3 g of glass bubble and 1.7 g of ceramic fiber were mixed by the manual dispersion method described above and the mixture was poured into the same graphite die as in Comparative Examples 1 to 4 . The setup was then subjected to the same sintering procedure as described in Comparative Example 1 above. The resulting disc had a density of 1.83 g / cc. The results of the three-point bending test are shown in Table 5 below.

Example 6 (EX-6)

10 g of Al powder, 0.5 g of glass bubble and 0.5 g of fiber were mixed by the manual dispersion method described above and the mixture was poured into the same graphite die as in Comparative Examples 1 to 4 and Example 5 . The setup was then subjected to the same sintering procedure as described in Comparative Example 1 above. The resulting disc had a density of 1.71 g / cc. The results of the three-point bending test are shown in Table 5 below.

Example 7 (EX-7)

8 g of Al 1-511 powder, 0.45 g of glass bubble, and 2.55 g of ceramic fiber were mixed by the passive dispersion method described above, and the mixture was mixed with Comparative Example 1 to Comparative Example 4, Example 5 and Example 6 Was poured into the same graphite die as in. The setup was then subjected to the same sintering procedure as described in Comparative Example 1 above. The resulting disc had a density of 1.78 g / cc. The results of the three-point bending test are shown in Table 5 below.

Example 8 (EX-8)

7 g of Al 1-511 powder, 0.6 g of glass bubble, and 3.4 g of ceramic fiber were mixed by the above-described passive dispersion method, and the mixture was mixed with Comparative Examples 1 to 4 and Examples 5 to 7 Was poured into the same graphite die as in. The setup was then subjected to the same sintering procedure as described in Comparative Example 1 above. The resulting disc had a density of 1.63 g / cc. The results of the three-point bending test are shown in Table 5 below.

[Table 5]

Example 9 (Comparative Example, CE-9)

10.8 grams (g) of Al 6063 powder was poured into a circular graphite die having an inner diameter of 1.575 inches (4.00 centimeters). Al 6063 powder was sintered as follows: The die was loaded into a Toshiba Machine GMP-411VA glass mold press machine (Toshiba Machine Co., Numazu, Japan) and the set up was purged with nitrogen Allowed to flood for 60 seconds, and then pumped down to vacuum. The die was heated from 40 占 폚 to 28 占 폚 / min (占 폚 / min) to 600 占 폚. Once the die reaches 600 占 폚, the die is maintained at that temperature while gradually increasing the force on the die from the applied force of zero to 21,000 Newtons (2400 psi (or 16.55 MPa) pressure for this size die) Respectively. A gradual increase in power occurred approximately linearly over the course of 20 minutes. Once the maximum force of 21,000 N was reached, the die was held in this state at 600 ° C for 1 hour. The pressure was then released and the die allowed to cool to room temperature. The envelope density of 2.51 grams per cubic centimeter (g / cc) was calculated by measuring the dimensions of the resulting sintered disc as well as its mass, which was 7% lower than the fully dense aluminum 6063. Strips approximately 0.5 inches (1.27 centimeters) wide and 1.5 inches (3.81 centimeters) wide were cut from the middle of the disc and subjected to the three-point bending test described above. The sample had a maximum tensile strength of 203 megapascals (MPa). The results are shown in Table 6 and FIG.

Example 10 (Comparative Example, CE-10)

8.64 g of Al 6063 powder and 0.48 g of alumina powder were mixed by the acoustic dispersion method described above and the mixture was poured into the same graphite die as in Comparative Example 9. The set-up was then subjected to the same sintering procedure as described in Comparative Example 9 above. The resulting sintered disc had an envelope density of 2.34 g / cc. The results of the three-point bending test are shown in Table 6 and Fig.

Example 11 (Comparative Example, CE-11)

9.72 g of Al 6063 powder and 1.56 g of ceramic fiber were mixed by the acoustic dispersion method described above and the mixture was poured into the same graphite die as in Comparative Example 9 and Comparative Example 10. The set-up was then subjected to the same sintering procedure as described in Comparative Example 9 above. The resulting disc had an envelope density of 2.65 g / cc. The results of the three-point bending test are shown in Table 6 and Fig.

Example 12 (EX-12)

7.56 g of Al 6063 powder, 0.48 g of alumina powder, and 1.56 g of ceramic fiber were mixed by the acoustic dispersion method described above, and the mixture was poured into the same graphite die as in Comparative Examples 9 to 11. The set-up was then subjected to the same sintering procedure as described in Comparative Example 9 above. The resulting disc had an envelope density of 2.45 g / cc. The results of the three-point bending test are shown in Table 6 and Fig.

Example 13 (EX-13)

5.4 g of Al 6063 powder, 0.96 g of alumina powder, and 1.56 g of ceramic fiber were mixed by the above-described acoustical dispersion method and the mixture was mixed with the same graphite die as in Comparative Examples 9 to 11 and Example 12 Poured. The set-up was then subjected to the same sintering procedure as described in Comparative Example 9 above. The resulting disc had an envelope density of 2.11 g / cc. The results of the three-point bending test are shown in Table 6 and Fig.

Example 14 (EX-14)

5.4 g of Al 6063 powder, 0.96 g of alumina powder, and 1.56 g of ceramic fiber were mixed by the above-described acoustical dispersion method, and the mixture was mixed in the same manner as in Comparative Example 9 to Comparative Example 11, Example 12 and Example 13 Poured into the same graphite die. The die was loaded into a Toshiba Machine GMP-411VA glass mold press machine (Toshiba Machine Company, Numazu, Japan) and the set up was flooded with nitrogen for 60 seconds and then pumped down to vacuum. The die was heated from 40 DEG C to 630 DEG C at 30 DEG C / min. Once the die reaches 630 占 폚, the die is maintained at that temperature while gradually increasing the force on the die from the applied force of zero to 34,664 Newtons (4000 psi (or 27.58 MPa) pressure for this size die) Respectively. A gradual increase in power occurred approximately linearly over the course of 20 minutes. Once the maximum force of 34,664 N was reached, the die was held in this state for 1 hour at 630 ° C. The pressure was then released and the die allowed to cool to room temperature. The resulting disc had an envelope density of 2.19 g / cc. The results of the three-point bending test are shown in Table 6 and Fig.

[Table 6]

Example 15 (Comparative, CE-15)

10.8 grams (g) of Al 6063 powder was poured into a circular graphite die having an inner diameter of 1.575 inches (4.00 centimeters). The Al 6063 powder was sintered as follows: the die was loaded into a Toshiba Machine GMP-411VA glass mold press machine (Toshiba Machine Company, Numazu, Japan) and the set up was flooded with nitrogen for 60 seconds and then vacuumed Pumped down. The die was heated from 40 占 폚 to 28 占 폚 / min (占 폚 / min) to 615 占 폚. Once the die reached 615 占 폚, the die was held at that temperature while gradually increasing the force on the die from a force of 0 to 21,000 Newton (pressure of 1600 psi for this size die). A gradual increase in power occurred approximately linearly over the course of 20 minutes. Once the maximum force of 21,000 N was reached, the die was held in this state at 600 ° C for 1 hour. The pressure was then released and the die allowed to cool to room temperature. The envelope density of 2.51 grams per cubic centimeter (g / cc) was calculated by measuring the dimensions of the resulting sintered disc as well as its mass, which was 7% lower than the fully dense aluminum 6063. Strips about 0.5 inches (1.27 centimeters) wide and 1.575 inches (4.00 centimeters) long were cut from the middle of the disc and subjected to the three-point bending test described above. The sample had a maximum tensile strength of 203 megapascals (MPa). The results are shown in Table 7 and FIG.

Example 16 (EX-16)

5.4 g of Al 1-511 powder, 0.96 g of glass bubble, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above, and the mixture was poured into the same graphite die as in Comparative Example 15. The die was loaded into a Toshiba Machine GMP-411VA glass mold press machine (Toshiba Machine Company, Numazu, Japan) and the set up was flooded with nitrogen for 60 seconds and then pumped down to vacuum. The die was heated from 40 占 폚 to 30 占 폚 / minute (占 폚 / min) to 615 占 폚. Once the die reached 615 占 폚, the die was held at that temperature, gradually increasing the force on the die from a force of 0 to 13,954 Newtons (1600 psi pressure for this size die). A gradual increase in power occurred approximately linearly over the course of 20 minutes. Once the maximum force of 13,954 N was reached, the die was held in this state for 1 hour at 615 ° C. The pressure was then released and the die allowed to cool to room temperature. The resulting disc had an envelope density of 1.93 g / cc. The results of the three-point bending test are shown in Table 7 and FIG.

Example 17 (EX-17)

5.4 g of Al 1-511 powder, 0.96 g of glass bubble, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 1.91 g / cc. The results of the three-point bending test are shown in Table 7 and FIG.

Example 18 (EX-18)

5.4 g of Al 1-511 powder, 0.96 g of Wright Star 106 senesphere, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 1.93 g / cc. The results of the three-point bending test are shown in Table 7 and FIG.

Example 19 (EX-19)

5.4 g of Al 1-511 powder, 0.96 g of high alumina 106 senesphere, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 1.95 g / cc. The results of the three-point bending test are shown in Table 7 and FIG.

Example 20 (EX-20)

5.4 g of Al 1100 powder, 0.96 g of Econosta 106 senesphere, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above, and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 1.93 g / cc. The results of the three-point bending test are shown in Table 7 and FIG.

[Table 7]

Example 21 (EX-21)

5.4 g of Al 1-511 powder, 0.96 g of partially sintered silicon carbide agglomerate particles, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above, and the mixture was added to the same graphite die as in Example 16 . The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 2.28 g / cc, a maximum tensile strength of 190 MPa and a breaking strain of 3.4%. The results of the three-point bending test are shown in Fig.

Example 22 (EX-22)

5.94 g of Al 1-131 powder, 0.96 g of Wright Star 106 senesphere, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 1.98 g / cc. The results of the three-point bending test are shown in Table 8 and FIG.

Example 23 (EX-23)

7.56 g of Al 1-131 powder, 0.6 g of Light Star 106 senesphere, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above, and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 2.21 g / cc. The results of the three-point bending test are shown in Table 8 and FIG.

Example 24 (EX-24)

7.02 g of Al 1-131 powder, 0.72 g of Wright Star 106 senesphere, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above, and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 2.12 g / cc. The results of the three-point bending test are shown in Table 8 and FIG.

Example 25 (EX-25)

7.02 g of Al powder, 0.72 g of Light Star 106 senesphere, and 0.78 g of ceramic fiber were mixed by the acoustic dispersion method described above, and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 2.00 g / cc. The results of the three-point bending test are shown in Table 8 and FIG.

[Table 8]

Example 26 (EX-26)

5.94 g of Al 1-131 powder, 0.84 g of Light Star 106 senesphere, and 1.016 g of glass fiber were mixed by the acoustic dispersion method described above and the mixture was poured into the same graphite die as in Example 16. The set-up was then subjected to the same sintering procedure as described in Example 16 above. The resulting disc had an envelope density of 2.00 g / cc, a maximum tensile strength of 159 MPa, and a fracture strain of 1.8%. The results of the three-point bending test are shown in Fig.

Although the present disclosure describes certain exemplary embodiments in detail, those skilled in the art will readily appreciate that modifications, changes, and equivalents may be devised by those skilled in the art upon reading the foregoing disclosure. In addition, all publications and patents referred to in this specification are incorporated by reference in their entirety to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. Various exemplary embodiments have been described. These and other embodiments are within the scope of the following claims.

Claims (14)

A method of making a porous metal matrix composite,
a. Mixing a metal powder, a plurality of inorganic particles, and a plurality of discontinuous fibers to form a mixture; And
b. Sintering the mixture to form the porous metal matrix composite
≪ / RTI > 2. The method of claim 1, wherein the mixture is sintered in a die. The method of claim 1 or 2, wherein the sintering is performed at a temperature of from 250 캜 to 1,000 캜. 4. The method of any one of claims 1 to 3, wherein the sintering comprises an applied pressure. 5. The method of claim 4, wherein the sintering is performed at a pressure of from 4 megapascals to 200 megapascals. 6. The method of any one of claims 1 to 5, wherein the mixing is performed using an acoustic mixer, a mechanical mixer, or a tumbler. 7. The method of any one of claims 1 to 6, wherein the mixture comprises the inorganic particles and the discontinuous fibers dispersed in the metal powder. The method of any one of claims 1 to 7, wherein the plurality of inorganic particles are selected from the group consisting of porous metal oxide particles, porous metal hydroxide particles, porous metal carbonate, porous carbon particles, porous silica particles, porous dehydrated aluminosilicate particles, Porous particles comprising dehydrated metal hydrate particles, zeolite particles, porous glass particles, expanded perlite particles, expanded vermiculite particles, porous sodium silicate particles, engineered porous ceramic particles, agglomerates of non-porous primary particles, ≪ / RTI > The method of any one of claims 1 to 7, wherein the plurality of inorganic particles comprises ceramic bubbles or glass bubbles. 10. The method of any one of claims 1 to 9, wherein the plurality of discontinuous fibers comprises glass, alumina, aluminosilicate, carbon, basalt, or a combination thereof. 11. The method of any one of claims 1 to 10, wherein the metal comprises aluminum, magnesium, an aluminum alloy, or a magnesium alloy. 12. A method according to any one of claims 1 to 11, wherein the metal matrix composite has an envelope density that is at least 8% lower than the density of the metal and is capable of withstanding a strain of 1% / RTI > 13. The method of claim 12, wherein the metal matrix composite is capable of withstanding a strain of 2% before fracture. 14. The method of any one of claims 1 to 13, wherein the metal matrix composite has a yield strength of at least 50 mega pascals.

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