JP2006002195A - Method for manufacturing porous metal glass, and porous metal glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish a method by which metal glass essentially requiring rapid cooling and having specific physical properties can be made porous. <P>SOLUTION: A metal glass material (1) and spacer particulates formed of a spacer substance (2) having a melting point higher than that of the metal glass material (1) are heated at a temperature between the melting point of the metal glass material (1) and the melting point of the spacer particulates (2) to melt the metal glass material (1) and disperse the spacer particulates (2) in the resultant molten metal glass (1a). Successively, rapid cooling is applied to the molten metal glass (1a) and the molten metal glass (1a) is solidified between the spacer particulates (2). Then the spacer particulates (2) are removed by means of a solvent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing porous metal glass and a porous metal glass formed by the method.

  Conventionally, voids in a metal are regarded as defects of the metal, and sintered metal having a large number of voids in the metal has been limited in its use because it lacks reliability as a structural material. However, recently, the use of voids in metals has been actively used, and the use has been rapidly expanded, including applications as materials with excellent specific strength and medical materials due to the penetration and affinity of bone tissue into voids. ing. However, these porous metals have no porous method for metallic glasses that require rapid cooling with commonly used crystalline metals such as iron, stainless steel, and silver.

  As a manufacturing technique of such a porous metal, a single crystal metal or a crystal alloy is produced in an isobaric gas atmosphere, and slow cooling is required to generate a porous metal pore. As one of them, according to the metal-gas equilibrium diagram, the metal glass is melted by utilizing the metal-gas eutectic reaction to dissolve a large amount of gas atoms and not to dissolve the gas in the solid metal. A technique for gradually cooling from the state to form a large amount of voids in the solid metallic glass has been disclosed (Japanese Patent Laid-Open No. 10-88254).

On the other hand, the metallic glass must be rapidly cooled from the molten state to be in the metallic glass state in the solid state. Therefore, in the rapid cooling method, the occluded gas remains in the metal glass and does not become a porous state, and in the conventional method, the rapid cooling becomes a bottleneck and the porous metal glass cannot be manufactured. As a result, it is known that metal glass has excellent physical properties, but the current method has not been able to produce a porous body of metal glass having this excellent physical property.
JP-A-10-88254

  The metallic glass is a material having special physical properties, that is, a special physical property of high strength, high modulus of elasticity, and low Young's modulus, and is a material that requires rapid cooling as described above. The problem to be solved by the present invention is that rapid cooling is indispensable, and is to establish a porous method for metallic glass having specific physical properties.

  The manufacturing method (FIG. 1) of the porous metallic glass (A) according to claim 1 is as follows: “A metallic glass material (1) and a spacer material (2) whose melting point is higher than that of the metallic glass material (1). The spacer glass particles formed in this way are heated at a temperature not lower than the melting point (Tm) of the metal glass material (1) and not higher than the melting point (Tm) of the spacer powder particles (2) to melt the metal glass material (1). Then, the spacer powder particles (2) are dispersed in the molten metal glass (1a) while the spacer powder particles (2) are in contact with each other. It is rapidly cooled to solidify the molten metal glass (1a) between the spacer powder particles (2), and then the spacer powder particles (2) are removed with a solvent (6). '' .

  The manufacturing method (FIG. 2) of the porous metallic glass (A) according to claim 2 is as follows: "The metallic glass material (1) and the main component of the metallic glass material (1) as its constituent elements, and the melting point thereof is the metallic glass material. A hydride that becomes a spacer material (2) having a melting point higher than the melting point of (1) is mixed, and then the mixture (3) is heated to melt the metallic glass material (1) and hydride (P ) And rapidly cooled during the generation of hydrogen bubbles (10) generated by the decomposition of the hydride (P) to turn the metallic glass material (1) into a foamed solidified body (1b).

  The method for producing the porous metallic glass (A) according to claim 3 (FIG. 3) is as follows: “The molten metal in the void (K) of the open-cell porous body (P) of the spacer material (2) having a melting point higher than that of the metallic glass material (1). After the glass (1a) is filled, it is rapidly cooled, and then the porous body (P) is removed with a solvent (6) ”.

  The method for producing the porous metallic glass (A) according to claim 4 (FIGS. 4 and 5) is as follows: “The metallic glass material (1) is melted, and then the pressure gas as the spacer substance (2) is melted into the molten metallic glass (1a). Metal glass (1a) being solidified by foaming and degassing of the occluded gas which is the spacer substance (2) in the molten metal glass (1a) after returning to a lower pressure from the pressurized state. The molten metal glass (1a) is rapidly cooled while bubbles (10) are formed therein. " Here, examples of the pressure gas that is the spacer substance (2) include Ar and nitrogen.

  The method for producing porous metallic glass according to claim 5 (FIG. 6) is “powder of metallic glass material (1) and granular material of spacer substance (2) having a melting point higher than the metallic glass transition temperature (Tg temperature). The mixture (3) is subjected to pressure sintering at a temperature immediately above the metallic glass transition temperature (Tg temperature), and then the spacer material (2) is removed from the mixed sintered body (3b) as a solvent. “Removed in (6)”.

  The manufacturing method (FIG. 7) of the porous metallic glass (A) according to claim 6 is as follows: “The metallic glass material (1) is melted in a high-pressure hydrogen atmosphere, and the spacer metal (2) is contained in the molten metallic glass (1). Alternatively, nitrogen is solid-dissolved, and then this is rapidly cooled to form a hydrogen-solid-dissolved metal glass body (1a ′) or nitrogen-solid-dissolved metal glass body, and then this hydrogen-solid-dissolved metal glass body (1a ′) Alternatively, the nitrogen solid solution metal glass body is heated within the range of (Tg-Tx temperature) to promote the bubble formation of the solid solution hydrogen (2) or nitrogen, and the metal glass body (1a ′ ) ". The porous metallic glass (A) is shown in FIG.

  The method for producing a porous metallic glass according to claim 7, wherein the metallic glass material (1) is an iron group or a zirconium group when the spacer material (2) is nitrogen. The iron-based or zirconium-based metallic glass material (1) has a large amount of solid solution of nitrogen and is effective for foaming.

  The porous metallic glass (A) of claim 8 is “formed by any one of the manufacturing methods according to claims 1 to 7”.

  The method according to claims 1 to 7 made it possible to produce a porous metallic glass (A).

  Hereinafter, the present invention will be described in order according to the illustrated embodiments. Examples of the metallic glass (A) subject to the present invention include zirconium-based, lead-based, iron-based, aluminum-based, titanium-based, nickel-based, copper-based, magnesium-based, palladium-based, etc. , Mg-Ln- (Ni, Cu, Zn), Ln-Al-Tm, Zr-Al-Tm, Fe- (Al, Ga)-(P, B, C, Si), Pd-Cu-Ni-P , Fe- (Zn, Hf, Nb) -B (wherein Ln = rare earth metal, Tm = IV to VIII transition metal) and other multi-component alloys ”, and glass transition temperature The conversion vitrification temperature (Tg / Tm) is 0.55 to 0.7, and the supercooled liquid region (Tx−Tg) has a width of 20 ° C. to 127 ° C. or more.

  Here, Tx is the crystallization temperature of the metallic glass (A), Tg is the metallic glass transition temperature of the metallic glass (A), and Tm is the melting point of the metallic glass (A).

In general formula, Xa-Yb-Mc (X is one or more metals selected from Zr, Ti, Hf, La, Mg, Al, Fe, Co, Ni and rare earth metals, Y is Al, One or more metals selected from Zr, Hf, Ti, Mo, Ta, Nb and rare earth metals, and M is one or more metals selected from Fe, Co, Ni, Pd, Ag, Cu and rare earth metals. A = 50 to 80, b = 0 to 20, c = 0 to 50), and specific examples include Zr ₆₀ Al ₁₅ Ni ₂₅ , Zr ₆₅ Al _7.5 Ni _27.5 , _{Zr 55 Al 10 Ni 5 Cu 30} , Zr 55 Ti 5 Al 10 Ni 10 Cu 20, Fe 73 Al 5 Ga 2 P 10 C 6 B 4, Fe 58 Co 7 Ni 7 Zr 10 B 18, Fe 58 Co 7 Ni 7 Zr ₃ Mo ₇ B ₁₈ , Fe ₅₈ Co ₇ Ni ₇ Mo ₁₀ B ₁₈ , La ₅₅ Al ₂₅ N i ₂₀ , Mg ₅₅ Cu ₂₅ Y ₁₀ , Mg ₆₀ Ni ₂₀ La ₂₀ and the like.

  The conversion vitrification temperature is an unnamed number defined by (Tg / Tm), and is used as a required cooling rate parameter.

  The supercooled liquid region is represented by ΔTx, is defined by ΔTx = Tx−Tg, and indicates a parameter of the degree of stability of the supercooled liquid.

The spacer substance (2) used in the present invention is
(B) It is not limited to a solid, but may be a gas such as hydrogen, and (b) a metal glass material (1) having a melting point equal to or higher than the metal glass transition temperature (Tg), or ( C) A material having a melting point (Tm) higher than that of the metallic glass material (1) is selected. And
(D) Even if the metal glass material (1) does not form an alloy or is alloyed, it is limited only to the surface layer of the generated porous metal glass (A), and the alloyed surface layer is acid, alkali, etc. As long as it can be removed with any chemical, it does not matter.
(E) Further, it is necessary that the molten metal glass material (1a) can be dissipated from the solidified metal glass (1b) during solidification or after solidification, or can be eluted and removed with an acid, alkali, water or other solvent (6).

When the spacer material (2) is a solid, the shape is not particularly limited, but in the case of the present invention, the granular material (2) is used for the purpose of forming a porous body. The particle size is not particularly limited. The spacer substance (2) is specifically described, for example, NaCl [melting point = 801 ° C.] (ionic bond salt), CaCO ₃ , MgOCO ₃ (carbonate), MgO [melting point = 2830 ° C.] (oxide), CaO [Melting point = 2,570 ° C.] (oxide). In the first embodiment, NaCl is used in the present invention.

  The metallic glass material (1) is a component material for producing the metallic glass (A) or a material having a metallic glass composition (in other words, pulverized powder of the metallic glass (A)), but the metallic glass (A When using each component material to produce ()), it is difficult to make metal glass (A) when melting with spacer substance (2), so usually use pulverized powder of metal glass (A) To do.

  The heating means (8) used in the present invention is an electric furnace, an induction heating device or the like, and the storage container (crucible) used for heating is, for example, a quartz tube (7) with a bottom having an upper end opening.

  The refrigerant (5) used in the present invention is water, liquid nitrogen, oil or the like, and water is used in this embodiment.

  The solvent (6) used in the present invention is an acid, an alkali, water, or an organic solvent, and here, water or an acid is used.

  Next, a first embodiment (FIG. 1) of the present invention will be described. First, the required amount of the metallic glass material (1) and the spacer material (2) in the quartz tube (7) is required (metal glass material: spacer granular material = 6: 4 to 8: 2). [Volume ratio]). The injection method may be the case where the quartz glass material (1) and the spacer powder (2) are mixed well, or divided into two layers as shown in FIG. You may make it throw in in the state.

  A pinhole or a fine through hole (18) is formed at the bottom of the quartz tube (7) of the first embodiment, and is melted by pressurization or suction from the bottomed quartz tube (7). Although the metallic glass (1a) does not flow out, the pressurized gas blown into the quartz tube (7) at a high pressure flows out from the fine through hole (18). The heating temperature is controlled to a temperature at which the metallic glass material (1) melts but the spacer granular material (2) does not melt.

  Subsequently, the inert gas (Ar) is supplied from the cylinder (9) (= argon supply cylinder in this embodiment) installed in the opening of the quartz tube (7) to the inert gas (= 0.3 MPa in this embodiment). Argon gas) is blown into the quartz tube (7), the inert gas blown into the inside through the fine through hole (18) at the bottom of the quartz tube (7) is discharged, and the molten metal in the quartz tube (7) is discharged. Stir the glass material (1a) so that the molten metal glass (1a) enters the voids of the spacer powder (2) [Of course, if it is like this at the time of melting, it is inactive Gas blowing is not always necessary. ]. In this state, the quartz tube (7) is immersed in the refrigerant (5) (water, oil or liquid nitrogen) to rapidly cool the molten metal glass (1a). As a result, the molten metal glass material (1a) that has entered the voids of the spacer powder particles (2) is rapidly cooled to become a metal glass solidified material (1b) containing the spacer powder particles (2) without crystallization.

  Subsequently, the solidified metal glass (1b) containing the spacer powder (2) is taken out from the quartz tube (7), and the solvent (6) (when the spacer powder (2) is a salt [eg, NaCl]. Then, the solvent (6) is immersed in water) to dissolve the spacer powder (2) into the solvent (6). As a result, an open-cell porous metallic glass (A) block is obtained.

The second embodiment (FIG. 2) of the porous metallic glass (A) is as follows. For example, a Zr-Al-Ni-Cu-based metallic glass material (1) and a hydride such as ZrH ₂ having the main component (Zr) of the metallic glass material (1) as its constituent element [this is a spacer material (2 ).]. Subsequently, the mixture (3) is heated in an electric furnace (8) to melt the metal gas material (1) at about 800 ° C. and decompose the hydride as the pacer substance (2), thereby generating hydrogen bubbles (10). generate. The hydrogen bubbles (10) ascend in the molten metal glass (1a) to form a bubble space extending vertically. When the molten metal glass (1a) is rapidly cooled (for example, water-cooled) while the hydrogen bubbles (10) are generated, innumerable bubble spaces remain in the metal glass material (1) to form the metal glass foam (A). In this case, when ZrH ₂ which becomes the spacer substance (2) is decomposed, the remaining in the molten metal glass (1a) is the main component Zr, so the composition is not significantly changed, and the metal glass The physical properties can be maintained.

  A third example (FIG. 3) of the porous metallic glass (A) is as follows. In this case, an open-cell porous body (P) having a predetermined shape is formed in advance from particles of a high melting point spacer material (2) (in this embodiment, NaCl) from the metal glass (A). The outer surface of the porous body (P) except for the pouring port (20) is formed with a closed wall so that the molten metal glass (1a) does not flow out (of course, the high melting point spacer material (2 ) Particles may be filled).

  On the other hand, the metallic glass material (1) is melted by induction heating using the quartz tube (7) as described above, and the molten metallic glass (1a) is poured from the pouring port (20) into the porous body (P). Subsequently, this is put into the refrigerant (5) (in this example, water) to rapidly cool the molten metal glass (1a). Thereby, the molten metal glass (1a) is solidified while maintaining the state of the metal glass. In other words, the metal glass solidified body (1b) containing particles of the high melting point spacer substance (2) is obtained. Then, if left in the refrigerant (5) as it is, the spacer substance (2) gradually dissolves in the refrigerant (5) (in this case, the water as the refrigerant (5) also serves as the solvent (6)), and finally Thus, an open-cell porous metallic glass (A) block is obtained. (2) in FIG. 3 schematically shows the removed NaCl.

  A fourth example (FIG. 4) of the porous metallic glass (A) is as follows. As in Example 1, the metallic glass material (1) is put in the quartz tube (7), and the opening of the quartz tube (7) is filled with hydrogen (or a mixed gas of hydrogen and argon) or nitrogen (9 ) To make the metallic glass material (1) hydrogen (or a mixed gas of hydrogen and argon) or nitrogen atmosphere, and then the metal in the quartz tube (7) or nitrogen by an electric furnace (8) or induction heating. Melt the glass material (1). Since the metallic glass material (1) is melted under hydrogen (or a mixed gas of hydrogen and argon) or nitrogen, the molten metallic glass (1a) contains a large amount of hydrogen or nitrogen (this is the spacer material (2)). Occlude (solid solution).

  Subsequently, the fused metal glass (1a) is obtained by switching the opening of the quartz tube (7) to the pump (11) and exhausting rapidly from the quartz tube (7) by bubbling the occluded hydrogen as the spacer material (2). The quartz tube (7) is immersed in the refrigerant (5) while foaming, and the fused quartz glass (1a) is rapidly cooled, solidified while maintaining the metallic glass state in the foamed state, and taken out from the quartz tube (7). . As a result, an open-cell porous metallic glass (A) block is obtained.

  As another method (Claim 6; FIG. 7), the metallic glass material (1) is put into the quartz tube (7) as described above, and the opening of the quartz tube (7) is hydrogen (or a mixed gas of hydrogen and argon) or Connected to a cylinder (9) filled with nitrogen or the like to make the metallic glass material (1) into hydrogen (or a mixed gas of hydrogen and argon) or nitrogen atmosphere, and then quartz by electric furnace (8) or induction heating Melt the metallic glass material (1) in a tube (7) or nitrogen. Since the metallic glass material (1) is melted under hydrogen (or a mixed gas of hydrogen and argon) or under nitrogen pressure (4 MPa or less in this embodiment), the molten metallic glass (1a) contains a large amount of hydrogen or nitrogen (this is a spacer). Occlude (solid solution) substance (2).

  Subsequently, the molten metal glass (1a) for each quartz tube (7) is cooled (water quenching in this embodiment) to form a metal glass hydrogen solid solution (1b) or a metal glass nitrogen solid solution. After that, the quartz tube (7) was connected to a vacuum (exhaust) pump (11), and the quartz tube (7) was depressurized, and then the metallic glass hydrogen solid solution (1b) or the metallic glass nitrogen solid solution was replaced with Tg ( Reheating the metal glass (A) from the metal glass transition temperature) to Tx (metal glass crystallization temperature) and below to release the hydrogen or nitrogen dissolved in the softened metal glass to make it porous. At the same time, the softened and porous metallic glass is again rapidly cooled (water quenching) to fix the porous state. As a result, an open-cell porous metallic glass (A) block is obtained. In this case, an infinite number of through holes having a circular cross section and various diameters are formed.

  In this case as well, as described above, it is necessary to appropriately perform the gas exhaust, the cooling timing, and the cooling rate. When the gas is exhausted insufficiently, the gas is taken into the metal glass. On the contrary, if the rapid cooling is slow, the gas will be exhausted and then cooled rapidly, and the porous state will not be achieved. The solid solution amount of hydrogen can be controlled by the atmospheric pressure of hydrogen (or a mixed gas of hydrogen and argon).

  As a degassing method, the inside of the quartz cylinder (7) may be directly depressurized by the pump (11) as described above, or the stirring gas (12) (such as Ar or nitrogen) may be used as shown in FIG. A molten metal glass (1a) such as hydrogen or a mixed gas of Ar and hydrogen) is introduced into the quartz tube (7) and the molten metal glass (1a) is stirred. Or after closing the upper opening of the quartz cylinder (7a) in the melted state without introducing the stirring gas (12), and for rapid cooling connected to the bottom (7b) of the quartz cylinder (7a) The piston (14) of the cylinder (13) is operated to rapidly expand the molten metal glass storage space (15) in the quenching cylinder (13) from the quartz cylinder (7a), and the space (15) is rapidly decompressed. (Adiabatic expansion), the occluded gas which is the spacer material (2) occluded in the molten metal glass (1a) is rapidly released from the molten metal glass (1a) and rapidly The molten metal glass (1a) sucked into the quenching cylinder (13) with a large mass of the cooling cylinder (13) may be quenched to obtain an open-cell porous metal glass (A) block. . In this case, in order to increase the rapid cooling rate by the rapid cooling cylinder (13), it is preferable that the rapid cooling cylinder (13) is made of copper having excellent thermal conductivity and has a water cooling structure.

Next, a method for producing the porous metallic glass (A) of Example 5 (FIG. 6) will be described. In this case, the metal glass powder (1) (in this case, it is not the powder of each composition material of the metal glass, but the powder that has already become the metal glass. For example, Zr ₅₅ Al ₁₀ Ni ₅ Cu ₃₀ ), Spacer material that does not form an alloy with metal glass Spacer material (2) powder (for example, an average particle diameter of CaCO ₃ is preferably 10 μm and smaller than the average particle diameter of metal glass) is mixed, and this mixture ( 3) Put in the mold (18), press it with the piston (16) (17) (also serves as an electrode) from above and below, and heat it by energization heating (for example, pulse energization effective for sintering of metal glass) and transition to metal glass Pressurize in the vicinity of temperature (Tg) and press into a predetermined shape. This state is a mixed and sintered state of the metallic glass powder (1) and the spacer substance (2) powder. In other words, such mixed powder compaction is performed in a state where the powders of the spacer material (2) are kept in contact with each other while the metallic glass powders (1) are partially bonded by sintering. After forming the body (3b), this mixed powder compact (3b) is cooled with a mold (18) (similar to the above, a copper water-cooled mold). Thereafter, this mixed powder compact (3b) is immersed in a solvent (6) (when the spacer substance (2) is CaCO ₃ , 0.1 mol / liter nitric acid [HNO ₃ ] is used). The spacer material (2) existing between the sintered metal glass powders of the de-spacer sintered body (3c) is dissolved and removed. As a result, an open-cell porous metallic glass (A) block is obtained. The following are the molding conditions of Example 5 (Table 1).

Compression ratio = Apparent density / Compression density Porosity = Pore ratio The characteristics of the block of the porous metallic glass (A) obtained by the above method are:
(a) Low density.
(b) When the surface is open with open cells, the surface area becomes very large.
(c) Young's modulus is lower than that of the original metallic glass.
(d) Realize a large plastic strain.

  By using this manufacturing method, an open-cell porous metallic glass block can be obtained, making use of the characteristics of excellent metallic glass, filtering materials in harsh environments, special electromagnetic shielding materials, catalyst materials, hydrogen storage alloy materials It is widely applied to high wear-resistant bearing materials, biomaterials, golf materials, eyeglass frame materials, sound deadening materials, automobile, aircraft, transportation equipment parts materials, and the like.

It is drawing which shows the procedure of 1st Example of this invention. It is drawing which shows the procedure of 2nd Example of this invention. It is drawing which shows the procedure of 3rd Example of this invention. It is drawing which shows the procedure of 4th Example of this invention. It is drawing which shows the other procedure of 4th Example of this invention. It is drawing which shows the procedure of 5th Example of this invention. It is drawing which shows the procedure of 6th Example of this invention. It is a microscope picture figure of the porous metal glass of FIG.

Explanation of symbols

(A) Porous metallic glass
(1) Metallic glass material
(1a) Molten metal glass
(1a ') Hydrogen or nitrogen solid solution metallic glass body
(1b) Foam solidified body
(2) Spacer material (spacer powder)

Claims (8)

  Heating a metallic glass material and spacer powder particles formed of a spacer material whose melting point is higher than that of the metallic glass material at a temperature not lower than the melting point of the metal glass material and not higher than the melting point of the spacer powder particles. Then, the metal glass material is melted so that the spacer powder particles are dispersed in the molten metal glass in contact with each other, and then the molten metal glass is rapidly cooled between the spacer powder particles. A method for producing a porous metallic glass, characterized in that the molten metallic glass is solidified, and thereafter the spacer powder is removed with a solvent.   A metallic glass material is mixed with a hydride which is a spacer substance whose melting point is higher than the melting point of the metallic glass material, the main component of the metallic glass material being the constituent element, and then heating the mixture. A porous metallic glass characterized in that the metallic glass material is melted and the hydride is decomposed, and the metallic glass material is made into a foam by quenching during the generation of hydrogen bubbles generated by the decomposition of the hydride. Production method.   A porous metal characterized by filling a void of an open-cell porous body of a spacer substance having a melting point higher than that of metal glass with a molten metal glass material, and then rapidly cooling it, and thereafter removing the porous body with a solvent. Glass manufacturing method.   The metal glass material is melted, and then a pressure gas, which is a spacer material, is injected into the molten metal glass. After that, the pressure is reduced to a lower pressure and the occluded gas, which is a spacer material in the molten metal glass. A method for producing a porous metallic glass, characterized in that the molten metallic glass is rapidly cooled while bubbles are formed in the solidifying metallic glass by foaming degassing.   A metallic glass material granule and a spacer material powder having a melting point equal to or higher than the metal glass transition temperature (Tg temperature) are mixed, and this mixture is added at a temperature just above the metal glass transition temperature (Tg temperature). A method for producing porous metallic glass, characterized in that pressure sintering is performed, and thereafter, a spacer substance is removed from the mixed sintered body with a solvent.   A metal glass material is melted in a high-pressure hydrogen atmosphere, and hydrogen or nitrogen as a spacer material is dissolved in the molten metal glass, and then rapidly cooled to obtain a hydrogen-solid metal glass body or a nitrogen-solid metal glass body. After that, the hydrogen solid solution metal glass body or the nitrogen solid solution metal glass body is heated within the range of (Tg-Tx temperature) to promote the formation of bubbles of the solid solution hydrogen or nitrogen. A method for producing porous metallic glass, comprising cooling a metallic glass body during generation of nitrogen bubbles.   When the spacer substance is nitrogen, the metallic glass material is an iron group or a zirconium group.   The porous metallic glass formed with the manufacturing method in any one of Claims 1-7.