Process for improving structure and property uniformity of manganin sintered damping alloy

Abstract

The invention discloses a process for improving structure and property uniformity of manganin sintered damping alloy. Decomposition products of cupric oxalate are used for replacing a part of copper powder, and then powder metallurgy manganin damping alloy is prepared. The cupric oxalate is thermally decomposed and reduced to obtain nanoscale highly active copper particles to promote sintering, released CO2 and a small amount of H2O vapor prevent a compact sealing layer from forming on the surface of a sintered blank, and then pyrolysis, presintering and sintering are carried out under the effect of H2. The pyrolysis of the cupric oxalate refers to carry out heat preservation for 1 to 4 hours at the temperature of 330 to 450 DEG C; presintering and reduction refer to carry out heat preservation for 1 to 4 hours at the temperature of 600 to 800 DEG C; the high-temperature sintering refers to carry out heat preservation for 2 to 4 hours at the temperature of 850 to 920 DEG C to complete the sintering process. For the prepared sintered alloy, the diameter is 100mm, the length is 200mm, the density is 5.10 to 5.75g / cm<3>, the hardness is 52 to 92HRF, the bending strength is within the range of 108 to 197MPa and the uniformity of a sintered body is good.

Description

technical field

[0001] The invention relates to a technique for atmosphere sintering porous structure manganese copper high damping alloy. By using copper oxalate as the iron element donor, the pyrolysis characteristics of copper oxalate and its decomposition products are used to improve the sintering process and achieve the purpose of uniform sintering of large-scale materials.

[0002] technical background

[0003] As a representative of twin-type damping materials, manganese-copper alloy has been widely used in various fields of life and production. The manganese-copper damping alloy material has the antiferromagnetic transformation of manganese-copper alloy with γ-phase structure, forming lattice distortion and triggering micro-twins. If the lattice distortion induces martensitic transformation, martensitic twins will be formed. The movement of parent phase and thermoelastic martensite phase interface and the movement of thermoelastic martensite twin substructure consume...

Examples

Embodiment 1

[0033] Manganese, copper, nickel, aluminum, tin, carbon, silicon and other powders and copper oxalate are batched according to the ingredients in Example 1 of Table 2. Place the prepared powder in a ball mill tank for dry milling, and the ball milling time is about 2 hours until the powder is uniform.

[0034] Table 2 Composition range (mass percentage) of the manganin-copper damping alloy of the embodiment

[0035] alloy element Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 mn 59.3 47.2 60 52 52 75 76.6 40 45 Cu 30 35 35.4 34.9 35.0 17.2 13 56 49 Cu* 3 4 0.5 1.0 0.7 0.8 4.0 2.0 5.0 Al 3.0 6.0 2.0 1.0 4.0 / / 2.0 1.0 Fe 2.4 3.2 1.0 4.0 3.0 2 1.8 / / Ni 0.8 3.2 0.3 2.2 2.5 5 4.6 / / sn 0.18 1.2 / / / / / / / Cr / / / / 0.6 / / / / Mo / / 0.2 0.9 / / / / / Zn / / 0.6 4.0 2.0 / ...

Embodiment 2

[0043] Powders such as manganese, copper, nickel, aluminum, tin, carbon, silicon and copper oxalate are batched according to the ingredients in Example 2 of Table 2. Put the prepared powder into a ball mill tank for dry milling, and the ball milling time is about 3 hours until the powder is uniform.

[0044] The mixed powder was pressed into a green compact under a pressure of 300 MPa using a circular die.

[0045] Pyrolysis, reduction and sintering under the protection of flowing dry hydrogen, the specific steps are 330°C for 4 hours; 600°C for 4 hours; 850°C for 4 hours; heating rate 5°C / min. With the cooling of the furnace, the sintered manganese copper is subjected to solid solution and aging treatment to obtain the product. The properties of the obtained sintered compacts are listed in Table 3.

Embodiment 3

[0047] Manganese, copper, nickel, aluminum, molybdenum, zinc powder and copper oxalate are batched according to the ingredients in Table 2 Example 3. Put the prepared powder into a ball mill tank for dry milling, and the ball milling time is about 0.5h until the powder is uniform.

[0048] The mixed powder was pressed into a compact under a pressure of 500 MPa using a circular pressing die.

[0049] Pyrolysis, reduction and sintering under the protection of flowing dry hydrogen, the specific steps are 400°C for 2 hours; 700°C for 2 hours; then 920°C for 2 hours, and the heating rate is 8°C / min. With the cooling of the furnace, the sintered manganese copper is subjected to solid solution and aging treatment to obtain the product. The properties of the obtained sintered compacts are listed in Table 3.

technical field

[0001] The invention relates to a technique for atmosphere sintering porous structure manganese copper high damping alloy. By using copper oxalate as the iron element donor, the pyrolysis characteristics of copper oxalate and its decomposition products are used to improve the sintering process and achieve the purpose of uniform sintering of large-scale materials.

[0002] technical background

[0003] As a representative of twin-type damping materials, manganese-copper alloy has been widely used in various fields of life and production. The manganese-copper damping alloy material has the antiferromagnetic transformation of manganese-copper alloy with γ-phase structure, forming lattice distortion and triggering micro-twins. If the lattice distortion induces martensitic transformation, martensitic twins will be formed. The movement of parent phase and thermoelastic martensite phase interface and the movement of thermoelastic martensite twin substructure consume...

Examples

Embodiment 1

[0033] Manganese, copper, nickel, aluminum, tin, carbon, silicon and other powders and copper oxalate are batched according to the ingredients in Example 1 of Table 2. Place the prepared powder in a ball mill tank for dry milling, and the ball milling time is about 2 hours until the powder is uniform.

[0034] Table 2 Composition range (mass percentage) of the manganin-copper damping alloy of the embodiment

[0035] alloy element Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 mn 59.3 47.2 60 52 52 75 76.6 40 45 Cu 30 35 35.4 34.9 35.0 17.2 13 56 49 Cu* 3 4 0.5 1.0 0.7 0.8 4.0 2.0 5.0 Al 3.0 6.0 2.0 1.0 4.0 / / 2.0 1.0 Fe 2.4 3.2 1.0 4.0 3.0 2 1.8 / / Ni 0.8 3.2 0.3 2.2 2.5 5 4.6 / / sn 0.18 1.2 / / / / / / / Cr / / / / 0.6 / / / / Mo / / 0.2 0.9 / / / / / Zn / / 0.6 4.0 2.0 / ...

Embodiment 2

[0043] Powders such as manganese, copper, nickel, aluminum, tin, carbon, silicon and copper oxalate are batched according to the ingredients in Example 2 of Table 2. Put the prepared powder into a ball mill tank for dry milling, and the ball milling time is about 3 hours until the powder is uniform.

[0044] The mixed powder was pressed into a green compact under a pressure of 300 MPa using a circular die.

[0045] Pyrolysis, reduction and sintering under the protection of flowing dry hydrogen, the specific steps are 330°C for 4 hours; 600°C for 4 hours; 850°C for 4 hours; heating rate 5°C / min. With the cooling of the furnace, the sintered manganese copper is subjected to solid solution and aging treatment to obtain the product. The properties of the obtained sintered compacts are listed in Table 3.

Embodiment 3

[0047] Manganese, copper, nickel, aluminum, molybdenum, zinc powder and copper oxalate are batched according to the ingredients in Table 2 Example 3. Put the prepared powder into a ball mill tank for dry milling, and the ball milling time is about 0.5h until the powder is uniform.

[0048] The mixed powder was pressed into a compact under a pressure of 500 MPa using a circular pressing die.

[0049] Pyrolysis, reduction and sintering under the protection of flowing dry hydrogen, the specific steps are 400°C for 2 hours; 700°C for 2 hours; then 920°C for 2 hours, and the heating rate is 8°C / min. With the cooling of the furnace, the sintered manganese copper is subjected to solid solution and aging treatment to obtain the product. The properties of the obtained sintered compacts are listed in Table 3.

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