Process for cold pressing-solving-vacuum sintering preparation of foamed aluminum

Abstract

The invention designs a kind of cold-press - dissolved - vacuum to agglutinate the preparation froth aluminum method, is the froth aluminum the preparation technology. The method including below process: In the 180~~200 goal aluminite powder, compared to is 40~~70% joins the average grain diameter according to the quality is 0.45~~1.00mm NaCl makes the hole medicinal preparation, and compared to joins 5% absolute ethyl alcohol according to the aluminite powder and the NaCl quality to carry on the intensive mixing; Above will match the good mix aluminite powder to lay aside in will rub has, will suppress the semifinished product under the 250~~350MPa pressure, then will set at the semifinished materials in the 75~~85deg.C water bath soaks causes NaCl to dissolve, again will use the deionized water repeatedly to wash eliminates remaining NaCl; After will go to NaCl the pressure semifinished product to agglutinate as for the vacuum oven, maintains in the stove vacuum degree 1*10 -3 power of exponent ~~1*10 -4 power of exponent Pa, will control 8-10deg.C / min to heat up the speed temperature rise and keeps warm 2-3h the stove to 540~~560deg.C, then will cool along with the stove to the room temperature system results in the froth aluminum. The invention merit lies in, technological process simple, the manufacture froth aluminum blowhole size even, the opening wall intensity is high controllably factor of porosity.

Description

technical field

[0001] The invention relates to a method for preparing foamed aluminum by cold pressing-dissolving-vacuum sintering, which belongs to the preparation technology of foamed aluminum. Background technique

[0002] Aluminum foam is a foam-like ultra-light metal material with the functions of penetration, sound absorption and vibration reduction. There are many ways to prepare it, mainly casting method, powder metallurgy method, deposition method, etc. Among these methods, powder metallurgy method has attracted attention because of its simple process and easy control of pore size and porosity. Among the powder metallurgy methods, the sintering and dissolution method is a new process for producing foamed aluminum developed in recent years. It is a method to prepare through-hole foamed aluminum by mixing aluminum powder and filler particles through processes such as mixing, pressing, sintering, and dissolving. It can precisely contr...

Examples

example 1

[0010] Example 1. After mixing 180-mesh aluminum powder and NaCl particles with a mass ratio of 1:1 of 0.45 to 0.66 mm, add 5% absolute ethanol and mix on a mixer for 4 hours. Put the mixed material in a mold at 250 MPa Pressed under pressure to 35×12.5×6.5mm 3 The strip sample was then immersed in water at 75-85°C to dissolve NaCl, and then washed with deionized water. After drying, place it in a high vacuum furnace and sinter at 540°C for 2h, heating at a rate of 10-15°C / min. The foamed aluminum prepared by this method has a porosity of 56% and a bending strength of 21MPa.

example 2

[0011] Example 2. Mix aluminum powder (-180 mesh) and NaCl particles (0.45-0.66mm) at a mass ratio of 1:1, add 5% absolute ethanol and mix on a mixer for 4 hours, put the mixed material in a mold Pressed into φ20×40mm under the pressure of 350MPa 3 The cylindrical sample was then immersed in water at 75-85°C to dissolve NaCl, and then washed with deionized water. After drying, place it in a high vacuum furnace and sinter at 550°C for 2h. The porosity of the aluminum foam prepared by this method is 56%, and the stress-strain curve of its compressive properties is as follows: Figure 4 shown.

example 3

[0012] Example 3. Mix aluminum powder (-180 mesh) and NaCl particles (0.66 ~ 0.90mm) at a mass ratio of 45:55, add 5% absolute ethanol and mix on a mixer for 4 hours, put the mixed material in the mold Pressed into φ20×40mm under the pressure of 350MPa 3 The cylindrical sample was then immersed in water at 75-85°C to dissolve NaCl, and then washed with deionized water. After drying, place it in a high vacuum furnace and sinter at 560°C for 2h. The porosity of the aluminum foam prepared by this method is 62%, and the stress-strain curve of its compressive properties is as follows: Figure 5 shown.

technical field

[0001] The invention relates to a method for preparing foamed aluminum by cold pressing-dissolving-vacuum sintering, which belongs to the preparation technology of foamed aluminum. Background technique

[0002] Aluminum foam is a foam-like ultra-light metal material with the functions of penetration, sound absorption and vibration reduction. There are many ways to prepare it, mainly casting method, powder metallurgy method, deposition method, etc. Among these methods, powder metallurgy method has attracted attention because of its simple process and easy control of pore size and porosity. Among the powder metallurgy methods, the sintering and dissolution method is a new process for producing foamed aluminum developed in recent years. It is a method to prepare through-hole foamed aluminum by mixing aluminum powder and filler particles through processes such as mixing, pressing, sintering, and dissolving. It can precisely contr...

Examples

example 1

[0010] Example 1. After mixing 180-mesh aluminum powder and NaCl particles with a mass ratio of 1:1 of 0.45 to 0.66 mm, add 5% absolute ethanol and mix on a mixer for 4 hours. Put the mixed material in a mold at 250 MPa Pressed under pressure to 35×12.5×6.5mm 3 The strip sample was then immersed in water at 75-85°C to dissolve NaCl, and then washed with deionized water. After drying, place it in a high vacuum furnace and sinter at 540°C for 2h, heating at a rate of 10-15°C / min. The foamed aluminum prepared by this method has a porosity of 56% and a bending strength of 21MPa.

example 2

[0011] Example 2. Mix aluminum powder (-180 mesh) and NaCl particles (0.45-0.66mm) at a mass ratio of 1:1, add 5% absolute ethanol and mix on a mixer for 4 hours, put the mixed material in a mold Pressed into φ20×40mm under the pressure of 350MPa 3 The cylindrical sample was then immersed in water at 75-85°C to dissolve NaCl, and then washed with deionized water. After drying, place it in a high vacuum furnace and sinter at 550°C for 2h. The porosity of the aluminum foam prepared by this method is 56%, and the stress-strain curve of its compressive properties is as follows: Figure 4 shown.

example 3

[0012] Example 3. Mix aluminum powder (-180 mesh) and NaCl particles (0.66 ~ 0.90mm) at a mass ratio of 45:55, add 5% absolute ethanol and mix on a mixer for 4 hours, put the mixed material in the mold Pressed into φ20×40mm under the pressure of 350MPa 3 The cylindrical sample was then immersed in water at 75-85°C to dissolve NaCl, and then washed with deionized water. After drying, place it in a high vacuum furnace and sinter at 560°C for 2h. The porosity of the aluminum foam prepared by this method is 62%, and the stress-strain curve of its compressive properties is as follows: Figure 5 shown.

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