Porous material

Abstract

The present invention relates to a porous material, wherein the pores of the porous material are uniformly distributed. The uniform distribution of the pores means that the pores are evenly distributed at any unit-level volume of the porous material. The elastic modulus of the porous material is reduced by 10-99% compared to that of the raw material used to make the porous material. This kind of porous material ensures the uniformity of its various properties. It is a porous material with excellent performance and quality. Its uniformity also ensures that its elastic modulus can be effectively reduced to meet multiple purposes.

Claims

1. A porous material, comprising a plurality of pores in a uniform distribution, wherein each cubic centimeter of the porous material is uniform in mass, and an absolute value of a deviation of the each cubic centimeter of the porous material is equal to or less than 4% by mass, referring that when a plurality of three-dimensional blocks with a volume of equal to or less than 1 cm.sup.3 and a same size are randomly taken from the porous material, each three-dimensional block of the plurality of three-dimensional blocks is weighed up respectively to obtain an average value of masses of the plurality of three-dimensional blocks, and the absolute value of the deviation of the each three-dimensional block from the average value of the masses is equal to or less than 4% of the average value of the masses of the plurality of three-dimensional blocks; and an elastic modulus of the porous material is reduced by 10-82% compared to a value of an elastic modulus of a raw material used to make the porous material.

2. The porous material according to claim 1, wherein the absolute value of the deviation of the each three-dimensional block from the average value of the masses is equal to or less than 2% of the average value of the masses of the plurality of three-dimensional blocks.

3. The porous material according to claim 1, wherein the porous material is composed of the pores classified into different levels according to a pore size and cavity walls surrounding to form the pores; the cavity wall forming upper-level large pores by surrounding a three-dimensional space are provided with lower-level small pores.

4. The porous material according to claim 1, wherein the elastic modulus of the porous material is reduced by 50 to 82%.

5. The porous material according to claim 3, wherein the elastic modulus of the porous material is reduced by 50 to 82%.

6. The porous material according to claim 1, wherein the elastic modulus of the porous material is reduced by 70 to 82%.

7. The porous material according to claim 3, wherein the elastic modulus of the porous material is reduced by 70 to 82%.

8. The porous material according to claim 2, wherein the elastic modulus of the porous material is reduced by 70 to 82%.

9. A porous material, comprising a plurality of pores in a uniform distribution, wherein each cubic millimeter of the porous material is uniform in mass, and an absolute value of a deviation of the each cubic millimeter of the porous material is equal to or less than 4% by mass, referring that when a plurality of three-dimensional blocks with a volume of equal to or less than 1 mm.sup.3 and a same size are randomly taken from the porous material, each three-dimensional block of the plurality of three-dimensional blocks is weighed up respectively to obtain an average value of masses of the plurality of three-dimensional blocks, and the absolute value of deviation of the each three-dimensional block from the average value of the masses is equal to or less than 4% of the average value of the masses of the plurality of three-dimensional blocks; and an elastic modulus of the porous material is reduced by 10-82% compared to a value of an elastic modulus of a raw material used to make the porous material.

10. The porous material according to claim 9, wherein the absolute value of the deviation of the each three-dimensional block from the average value of the masses is equal to or less than 2% of the average value of the masses of the plurality of three-dimensional blocks.

11. The porous material according to claim 9, wherein the elastic modulus of the porous material is reduced by 70 to 82%.

12. The porous material according to claim 10, wherein the elastic modulus of the porous material is reduced by 70 to 82%.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The present invention is further described below with reference to the accompanying drawings and embodiments.

(2) FIG. 1 is a structural schematic view of the porous material of the present invention, 1-1 is a front view, 1-2 is a left view, 1-3 is a top view;

(3) FIG. 2 is a structural schematic view of the porous material provided by embodiment 4 of the present invention, 2-1 is a front view, 2-2 is a left side view, 2-3 is a top view;

(4) FIG. 3 is a partial enlarged view of A in FIG. 2;

(5) FIG. 4 is a B-B sectional view in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

(6) The detailed embodiments are given on the premise of the technical solutions of the present invention, but the protection scope of the present invention is not limited to the following embodiments. Without departing from and changing the above technical idea of the present invention, according to common technical knowledge and/or usual means in the art, apparently various forms of substitutions and alterations can be made and should be included in the scope of the present invention

(7) As shown in FIG. 1, 1 is the pore, 2 is the cavity wall of the pore, the pores are uniformly distributed.

(8) As can be seen from FIG. 2 and FIG. 3, the cavity wall 4 of the pore 3 is formed by the smaller pores 5 (the next level pores) and the cavity wall 6 that is surrounding the pore 5. Referring to the enlarged view of the cavity wall 4 in FIG. 3 and the B-B sectional view in FIG. 4, the pore 5 is three-dimensionally interconnected, and the pores of two levels are also three-dimensionally interconnected.

(9) The embodiment of the present invention are given below in detail.

Embodiment 1

(10) The porous material of the present embodiment is porous stainless steel 316, the porosity of which is 75.5%, and composed of a square frame having a strut edge of 100 m, a strut diameter of 30 m and a unit of 12 strut edges. A cutting process is performed on the porous material to randomly get 10 pieces of three-dimensional blocks with the same size of 10 mm10 mm10 mm. Test their masses by a METTLER-TOLEDO XP26 Microbalance at an ambient temperature of 20 C. The measuring procedure is as follows.

(11) 1) Preheating: turn on the power, preheat the microbalance for a specified time.

(12) 2) The selection of basic mode of balance: tap the ON button, turn on the display, choose the normal mode.

(13) 3) Calibration: use Target (TAR) key to clear, use Calibration (CAL) minus and calibration weight to calibrate.

(14) 4) Weighing: press TAR key, the display is zero, then place the three-dimensional blocks successively on the scale pan, until the figure is stable, that is, the zero of the lower left corner of the display disappears, read the mass value of the three-dimensional block.

(15) The measurement results are shown in Table 1, wherein the absolute value of the deviation from the average value is expressed as a percentage, the value is the absolute value of the deviation from the average divided by the average of masses. As shown in Table 1, the mass deviation is less than 4%.

(16) TABLE-US-00001 TABLE 1 Piece Absolute Value of Deviation From the Number Mass (mg) Average Value (%) 1 1864.521 3.3% 2 1912.954 1.7% 3 1895.510 2.2% 4 1909.078 1.5% 5 1880.005 .sup.3% 6 2013.737 3.9% 7 1990.480 2.7% 8 1973.037 1.8% 9 1976.913 .sup.2% 10 1963.346 1.3% Average 1938.150 Mass

(17) According to GBT/7314-2005 Metallic materials-Compression testing at ambient temperature, use the Instron mechanical testing machine to test the compressive stress-strain curve of the above porous stainless steel 316 with a compression test at ambient temperature of 25 C. The initial deformation shown by the stress-strain curve is an elastic deformation. The ratio of the stress value of the elastic deformation part to the corresponding strain value is taken as the elastic modulus, the value of the elastic modulus is 35.1 GPa, compared to the raw material used in the porous material, the elastic modulus is reduced by 82%.

(18) A method of preparing the porous stainless steel 316 includes the following steps:

(19) step 1: using powder of stainless steel 316 having substantially spherical particles with an average particle size of 102 m;

(20) step 2: using CAD software to make a square frame-shaped porous material model with strut edge of 102 m, strut diameter of 30 m and unit of 12 strut edges;

(21) step 3: inputting the porous material model into the HRPM-IIB selective laser melting prototyping system, scanning according to the CAD software model with the scanning speed of 200 mm/min, when the laser beam completes a slice of area scanning, the cylinder is correspondingly descended by a thickness of the slice relative to the laser beam focal plane (forming plane), the thickness of slice is 30 m;

(22) step 4: proceeding stress relieving annealing; and

(23) step 5: proceeding abrasive blasting.

(24) The kind of material is used to make the filter element.

Embodiment 2

(25) The porous material of the present embodiment is porous nickel, having a porosity of 83% and an average pore diameter of 113 m. A cutting process is performed on the porous material to randomly get 10 pieces of three-dimensional blocks with the same size of 10 mm10 mm8 mm. Testing their masses with a METTLER-TOLEDO XP26 Microbalance. The temperature and procedure of the testing are the same as that in embodiment 1. The results are shown in Table 2, wherein, the absolute value of the deviation from the average value is expressed as a percentage, the value thereof is the absolute value of the deviation from the average divided by the average of masses. As can be seen from Table 2, the mass deviation is less than 2%.

(26) TABLE-US-00002 TABLE 2 Piece Absolute Value of Deviation From the Number Mass (mg) Average Value (%) 1 1225.532 0.39% 2 1229.165 0.69% 3 1200.100 1.69% 4 1240.796 1.64% 5 1224.320 0.29% 6 1197.412 1.91% 7 1219.475 0.1% 8 1235.220 1.19% 9 1226.740 0.49% 10 1208.562 1% Average 1220.632 Mass

(27) The elastic modulus of this kind of material measured by the method of Embodiment 1 is 15.6 GPa, which is 91% lower than that of the raw material used for the porous material.

(28) The preparation method of porous nickel is as follows:

(29) (1) substrate materials pretreatment: select a polyurethane foam with pore diameter of 1523 m, use hydrochloric acid for pretreatment;

(30) (2) conductive treatment: use physical vapor deposition to deposit a layer of nickel on the polyurethane foam.

(31) (3) electroplating: electroplate the polyurethane foam after conductive treatment with pulse current method, and electroplate the foam strut with nickel coating;

(32) (4) reductive sintering: perform the reduction treatment in a protective atmosphere containing 70% of hydrogen and 30% of nitrogen to prepare a porous nickel material.

(33) This kind of material is used to make electrodes.

Embodiment 3

(34) The porous material of the present embodiment is a porous polylactic acid having a porosity of 66% and an average pore diameter of 20 m. A cutting process is performed on the porous material to randomly get 10 pieces three-dimensional blocks with the same size of 1 mm1 mm1 mm. Measure the mass by a METTLER-TOLEDO XP26 Microbalance. The temperature and the procedure of measurement are the same as those in Embodiment 1, and the results are shown in Table 3. Wherein the absolute value of the deviation from the average value is expressed as a percentage, the value is the absolute value of the deviation from the average divided by the average mass. As shown in Table 3, the mass deviation is less than 4%.

(35) TABLE-US-00003 TABLE 3 Piece Absolute Value of Deviation From the Number Mass (mg) Average Value (%) 1 0.440 0.5% 2 0.437 .sup.1% 3 0.425 3.8% 4 0.438 0.8% 5 0.437 1.2% 6 0.449 1.5% 7 0.459 3.9% 8 0.451 .sup.2% 9 0.452 2.2% 10 0.432 2.3% Average 0.442 Mass

(36) With reference to GBT/1041-2008 Plastics-Determination of compressive properties, the elastic modulus of this kind of material measured by the method of Embodiment 1 is 0.96 GPa, which is 68% lower than the elastic modulus of the raw material itself used in the porous material.

(37) The preparation method of the porous polylactic acid is as follows:

(38) (1) freezing the polylactic acid in liquid nitrogen and pulverizing the polylactic acid by a high-speed pulverizer, after that, to sieve particles with the particle size of 20 m;

(39) (2) selecting NaCl particles with a particle size of 20 m;

(40) (3) mixing the polylactic acid particles and NaCl particles in a weight ratio of 17:33, stirring the mixture at a speed of 60 r/min for 2 hours at 22 C. by a low-speed stirrer to mix them uniformly;

(41) (4) putting the above mixture into a closed mould, pressing into blocks at 75 C. and at 7 MPa;

(42) (5) immerse the above blocks in double distilled water for 72 hours, change the water every 6 hours, completely remove NaCl to obtain the porous polylactic acid.

(43) This material is used to make medical implants.

Embodiment 4

(44) The porous material of the present embodiment is the porous niobium with a secondary pore structure, which is classified into different levels according to the pore size of the material. All the pores are three-dimensionally interconnected, and the total effective porosity is 94%. The average pore size of large pores is 122 m, and penetrating small pores with an average pore diameter of 10 m were formed in the cavity walls of the large pores.

(45) A cutting process is performed on the porous material to randomly get 9 pieces of three-dimensional blocks with the same size of 10 mm10 mm10 mm. Test the mass by a METTLER-TOLEDO XP26 Microbalance. The testing temperature and procedure are the same as those in Embodiment 1. The results are shown in Table 4, wherein the absolute value of the deviation from the average value is expressed as a percentage, the value is the absolute value of the deviation from the average divided by the average of masses. As shown in Table 4, the mass deviation is less than or equal to 4%.

(46) TABLE-US-00004 TABLE 4 Piece Absolute Value of Deviation From the Number Mass (mg) Average Value (%) 1 512.845 1.3% 2 513.365 1.2% 3 504.011 .sup.3% 4 508.169 2.2% 5 510.247 1.8% 6 498.816 .sup.4% 7 532.590 2.5% 8 529.992 .sup.2% 9 524.796 .sup.1% Average 519.600 Mass

(47) The elastic modulus of this kind of material measured by the method of Embodiment 1 is 1.05 GPa, which was 99% lower than that of the raw material used for the porous material.

(48) The preparation method of porous niobium is as follows:

(49) (1) material preparation

(50) using niobium powder with a particle size of 10 m and urea with a particle size of 15 m as pore-forming agent for the smallest pores, mixing uniformly and using starch with a particle size of 15 m as a binder, a slurry is prepared by the niobium powder, urea, starch and distilled water mixed in the volume ratio of 1:1.5:1:7.

(51) Filling the slurry uniformly into a polyester foam with a strut diameter of 1603 m by a foam impregnation method to form a green body; drying, and then pulverizing to obtain mixed grains with a particle size of 1603 m which contains niobium powder, a pore-forming agent and a polyester foam.

(52) (2) Uniformly mixing the mixed grains and methylcellulose with a particle size of 1603 m in a volume ratio of 1:8, and filling the mixture into a closed mould to press into a compact green body.

(53) (3) Sintering the compact green body at vacuum, and the sintered green body is subjected to conventional follow-up treatment according to the niobium process to obtain the porous niobium with secondary pores described in this embodiment.

(54) This material is used to make medical implants.

Embodiment 5

(55) The porous material of the present embodiment is porous copper with a porosity of 45.2% and an average pore diameter of 180 nm. A cutting process is performed on the porous material to randomly get 10 pieces of three-dimensional blocks with the same size of 1 mm1 mm1 mm. Test the mass by a METTLER-TOLEDO XP26 Microbalance. The temperature and the procedure of the measurement are the same as those in Embodiment 1. The results are shown in Table 5, wherein the absolute value of the deviation from the average value is expressed as a percentage, the value is the absolute value of the deviation from the average divided by the average of masses. As can be seen from Table 5, the deviation of mass is less than 2%.

(56) TABLE-US-00005 TABLE 5 Piece Absolute Value of Deviation From the Number Mass (mg) Average Value (%) 1 4.730 0.8% 2 4.725 0.9% 3 4.706 1.3% 4 4.692 1.6% 5 4.715 1.1% 6 4.859 1.9% 7 4.820 1.1% 8 4.811 0.9% 9 4.825 1.2% 10 4.801 0.7% Average 4.768 Mass

(57) The elastic modulus of this kind of material measured by the method of Embodiment 1 was 99 GPa, which was 10% lower than that of the raw material used for the porous material.

(58) The preparation method of porous copper is as follows:

(59) (1) selecting polystyrene beads with a particle size of 2004 nm;

(60) (2) assembling the polystyrene beads into a three-dimensionally arranged colloid template;

(61) (3) preparing the nanocrystalline copper solution;

(62) (4) directly introducing the nanocrystalline copper solution into the three-dimensional colloid template made of polystyrene beads, and the solution infiltrates among the polystyrene beads;

(63) (5) drying the mixture of three-dimensional colloid template/nanocrystalline copper solution;

(64) (6) dissolving the polystyrene beads with chloroform to obtain the porous copper of this embodiment.

(65) In the above preparation method, the nanocrystalline copper solution is prepared by using nanocrystalline copper powder with a particle size of 30-50 nm and deionized water, the concentration of the nanocrystalline copper solution is 0.08 g/ml, the drying temperature of mixture is 80 C.

(66) This kind of material is used to make the target materials.