CN1380147A - Method for preparing semi-solid blank material by using liquides line die stamping process - Google Patents

Abstract

The method for preparing semisolid blank material by using liquidus line die stamping process includes the following steps: in melting furnace mixing and melting alloy components according to the requirements, then injecting the above-mentioned mixture material into heat-insualting lalde, regulating temp. to make it be 3-5 deg.C higher than alloy liquidus line, after the internal temp. of heat-insulating ladle is uniformized to the required temp., injecting the melt being in heat-insulating ladle into die cavity, applying mechanical static pressure and retaining pressure so as to obtain the fine semisolid blank material and product with spherocrystal structure.

Description

Method for preparing semi-solid blank material by using liquides line die stamping process

The present invention proposes a kind of method for preparing semi-solid blank material by using liquides line die stamping process.

Method for preparing semisolid is a lot of, produces only electromagnetic stirring method but successfully be used at present.But its power consumption is big, and the preparation of inapplicable big specification (＞φ 152mm) blank also can not directly be made part.Strain-induced fusing activation method (SIMA) has the potentiality of commercial Application, but increases the predeformation operation one, has improved the blank cost, and simultaneously, it is only applicable to the small dimension blank, also can not the direct forming part.In addition, also have controlled cooled and solidified method and liquidus curve casting.But these methods all under study for action, and the blank specification also is restricted, and can not the direct forming part.

Purpose of the present invention proposes a kind of method for preparing semi-solid blank material by using liquides line die stamping process at the deficiency that prior art exists.

The tissue signature of semisolid blank: tiny, non-dendritic structure.And under usual conditions, the alloy of nearly all commercial Application all forms with dendrite.The principle of the invention: destroy the forming core condition and the condition of growing up that dendrite forms: 1. cast cold.Be controlled at and be higher than liquidus temperature 3-5 ℃ and pour into a mould; 2. group effect pressurizes.When most alloys under high pressure solidified, alloy graining point temperature linearly rose with the pressure increase; The alloy pressurized is to carry out at the sealing impression, and pressure spreads all over whole alloy liquid, no matter outer, or internal layer, all be subjected to same big or small pressure, produce the effect that same freezing point rises.Like this, after alloy pours into impression, be in zero superheat state, exert pressure immediately, alloy graining point rises, and whole alloy liquid enters supercooled state simultaneously, realizes whole nucleation simultaneously.In the nuclei growth connection process afterwards, the resistance that is subjected to contiguous nuclei growth is very big, does not form the condition of flourishing dendrite.The tissue of Xing Chenging must be tiny, the underdeveloped tissue of dendrite at last.Before thixotropic forming in the blank post bake process, and further nodularization, form the microstructure of semisolid of spherocrystal at last.

The present invention realizes according to the following steps:

The first step in melting furnace, is carried out alloying ingredient, fusing.

Second step: cast cold.Before the cast alloy liquid is carried out temperature adjustment to being higher than 3-5 ℃ on alloy liquid phase line.

The 3rd step: pressurization.Pressure is greater than 100MPa.

The 4th step: pressurize.Dwell time presses each millimeter of minimum dimension pressurize of product and selected in 0.5 second to 1.5 seconds.

The 5th step: product is ejected from mould.

Technological parameter of the present invention:

1. mold temperature:＞400 ℃;

2. specific pressure:＞100MPa;

3. dwell time: 0.5-1.5sec/mm;

4. lubricated: the finish aquadag;

5. pouring temperature.

Different-alloy, the pouring temperature difference.General the above 3-5 of alloy liquid phase line ℃, as shown in the table:

Alloy	The semi-solid temperature interval, ℃	The holding furnace temperature, ℃	Pouring temperature, ℃
				??LY12(2024) ??LD10(2014) ??LC 9(7075) ??ZM 5??ZM 10??AZ918 ??AM60A ??AS41A ??ZcuSnPb5Zn5 ??ZcuSn8Zn4 ??ZcuSn10Zn2	????502-638 ????507-638 ????477-635 ????430-600 ????400-600 ????470-595 ????540-615 ????565-620 ????853-1009 ????854-1000 ????854-1000	????643 ????643 ????640 ????605 ????605 ????600 ????620 ????625 ????1014 ????1005 ????1005	????641 ????641 ????638 ????603 ????603 ????598 ????618 ????623 ????1012 ????1003 ????1003

Technology of the present invention is easy, and the blank specification is not limit, can also be directly the preparation part, steady quality and with low cost, for semi-solid-state shaping the applying of metal manufacture field, will the positive effect of generation.

Embodiment 1:

LD10 bar semi-solid-state shaping

Bar specification: φ 120 * 250mm

Tissue: primary grain degree＜100 μ m

Mechanical property: under the CS state, б _0.2〉=380Mpa, б _b〉=480Mpa,

б≥10％

Technological parameter: mold temperature＞400 ℃, specific pressure＞100MPa

Dwell time: 60sec, 641 ℃ of pouring temperatures

Lubricated: the finish aquadag

Embodiment 2:

AlSi ₁₇Mg minicar piston semi-solid-state shaping

1) imitative example 1 is made excellent base φ 62 * 125, its technological parameter: mold temperature＞400 ℃, and specific pressure＞100MPa, dwell time 40sec, 620 ℃ of pouring temperatures, lubricated: by the agent aquadag;

2) cut into φ 62 * 40;

3) thixotropic forming: mold temperature＞300 ℃, specific pressure＞100MPa, 20sec during pressurize, 580 ℃ of semisolid blank post bake temperature;

4) mechanical property: under the CS state: б _b〉=270Mpa, б _0.2〉=2%.

Claims (1)

1, a kind of method for preparing semi-solid blank material by using liquides line die stamping process is characterized in that: realize according to the following steps:

The first step in melting furnace, is carried out alloying ingredient, fusing.

Second step: cast cold.Before the cast alloy liquid is carried out temperature adjustment to being higher than 3-5 ℃ on alloy liquid phase line.

The 3rd step: pressurization.Pressure is greater than 100MPa.

The 4th step: pressurize.Dwell time presses each millimeter of minimum dimension pressurize of product and selected in 0.5 second to 1.5 seconds.

The 5th step: product is ejected from mould.