阅读说明：本技术 铝硅合金及其制备方法 (Aluminum-silicon alloy and preparation method thereof ) 是由 李德松 李其荣 浦俭英 于 2020-12-25 设计创作，主要内容包括：本申请涉及一种铝硅合金及其制备方法。铝硅合金包括以下质量百分比的成分：3.5％-4.5％的硅；0.7％-1.0％的镁；0.5％-0.7％的锰；0.03％-0.1％的钛；余量的铝。铝硅合金的制备方法包括以下步骤：称取原料；熔炼原料至全部熔化；浇注熔化后的原料,形成棒料；均匀化处理棒料,并冷却；预热并挤压成型棒料,形成合金产品；在线水冷合金产品,并经时效处理。本申请所制备的合金产品的屈服强度可以达到280-320MPa,边部再结晶区厚度小于1mm,切削性能较好,且合金产品中不含有铅和铜,既符合环保要求,又可以提高合金产品的耐腐蚀性能,使其能够应用于耐腐蚀性能要求较高的场合。(The application relates to an aluminum-silicon alloy and a preparation method thereof. The aluminum-silicon alloy comprises the following components in percentage by mass: 3.5% -4.5% of silicon; 0.7-1.0% magnesium; 0.5% -0.7% manganese; 0.03% -0.1% titanium; the balance being aluminum. The preparation method of the aluminum-silicon alloy comprises the following steps: weighing raw materials; smelting the raw materials until the raw materials are completely melted; pouring the melted raw materials to form a bar stock; homogenizing the bar stock and cooling; preheating and extruding a bar stock to form an alloy product; and carrying out on-line water cooling on the alloy product and carrying out aging treatment. The yield strength of the alloy product prepared by the method can reach 280-320MPa, the thickness of the side recrystallization zone is less than 1mm, the cutting performance is good, and the alloy product does not contain lead and copper, so that the alloy product meets the requirement of environmental protection, and the corrosion resistance of the alloy product can be improved, so that the alloy product can be applied to occasions with high requirements on corrosion resistance.)

1. The aluminum-silicon alloy is characterized by comprising the following components in percentage by mass:

3.5% -4.5% of silicon;

0.7-1.0% magnesium;

0.5% -0.7% manganese;

0.03% -0.1% titanium;

the balance being aluminum.

2. The aluminum-silicon alloy according to claim 1, wherein the mass percentage of iron impurities in the balance aluminum is 0.20% or less.

3. The preparation method of the aluminum-silicon alloy is characterized by comprising the following steps of:

weighing raw materials according to the aluminum-silicon alloy of any one of the claims 1-2;

smelting the raw materials to be completely molten;

pouring the melted raw materials to form a bar stock;

homogenizing the bar stock, and cooling;

preheating and extruding the bar stock to form an alloy product;

and carrying out on-line water cooling on the alloy product, and carrying out aging treatment.

4. The method for producing an aluminum-silicon alloy according to claim 3, wherein when the molten raw material is poured, Mg is produced in the course of solidification of the raw material₂As the temperature of Si is further lowered, excessive Si precipitates in grain boundaries.

5. The method for preparing the aluminum-silicon alloy as claimed in claim 3, wherein the heat temperature for preheating the bar stock is 460-480 ℃.

6. The method for manufacturing an aluminium silicon alloy according to claim 3, characterised in that the silicon in the alloy product is an alpha + Si eutectic, Mg₂Si and free Si forms.

7. The method for preparing an Al-Si alloy according to claim 3, characterized in that the temperature for aging the alloy product is 170-180 ℃ and the time is 8 h.

8. The method of manufacturing an aluminium silicon alloy according to claim 3, characterised in that the thickness of the edge recrystallization zone of the alloy product is less than 1 mm.

9. The method of manufacturing an aluminium silicon alloy according to claim 3, characterised in that the yield strength of the alloy product is 280-320 MPa.

10. The method for producing the aluminum-silicon alloy according to claim 3, further comprising the steps of, before casting the raw material: preheating equipment used in the casting process, and baking the launder, the degassing tank, the filter box and the die plate.

Technical Field

The application relates to the technical field of precision part processing and preparation, in particular to an aluminum-silicon alloy and a preparation method thereof.

Background

The free-cutting aluminum alloy is one of important raw materials of modern precision instruments, and has the characteristics of good chip breaking performance and high surface smoothness after processing. The traditional free-cutting aluminum alloy has 2011 and 6262, and the basic principle is that lead (Pb) and bismuth (Bi) are added into the alloy to form a low-melting eutectic phase in the alloy, and the low-melting eutectic phase is softened and melted in the cutting process to facilitate cutting fracture, so that good cutting performance is obtained. However, since lead (Pb) is harmful to the human body, some foreign countries have issued laws and prohibited the application of lead-containing aluminum alloys, and thus a new aluminum alloy is urgently needed to replace the conventional lead-containing aluminum alloy.

Disclosure of Invention

In order to solve the technical problems in the prior art, embodiments of the present application provide an aluminum-silicon alloy and a preparation method thereof. The specific technical scheme is as follows:

in a first aspect, an aluminum-silicon alloy is provided, which comprises the following components by mass percent: 3.5% -4.5% of silicon; 0.7-1.0% magnesium; 0.5% -0.7% manganese; 0.03% -0.1% titanium; the balance being aluminum.

In a first possible implementation manner of the first aspect, the mass percentage of iron impurities in the balance of aluminum is below 0.20%.

In a second aspect, a method for preparing an aluminum-silicon alloy is provided, which comprises the following steps: weighing raw materials according to the aluminum-silicon alloy in any one of the first aspect; smelting the raw materials until the raw materials are completely melted; pouring the melted raw materials to form a bar stock; homogenizing the bar stock and cooling; preheating and extruding a bar stock to form an alloy product; and carrying out on-line water cooling on the alloy product and carrying out aging treatment.

In a first possible implementation manner of the second aspect, when the melted raw material is poured, Mg2Si is generated in the process of solidification of the raw material, and as the temperature continues to decrease, excess Si is precipitated at grain boundaries.

In a second possible implementation of the second aspect, the hot temperature of the preheated bar stock is 460-.

In a third possible implementation of the second aspect, the silicon in the alloy product is present in the form of an α + Si eutectic, Mg2Si and free Si.

In a fourth possible implementation manner of the second aspect, the temperature for aging the alloy product is 170-180 ℃ and the time is 8 h.

In a fifth possible implementation form of the second aspect, the thickness of the edge recrystallization zone of the alloy product is less than 1 mm.

In a sixth possible implementation form of the second aspect, the yield strength of the alloy product is 280MPa to 320 MPa.

In a seventh possible implementation manner of the second aspect, the casting of the raw material further comprises the following steps: preheating equipment used in the casting process, and baking the launder, the degassing tank, the filter box and the die plate.

Compared with the prior art, the application has the advantages that:

according to the aluminum-silicon alloy and the preparation method thereof, the yield strength of the prepared alloy product can reach 280-320MPa, the thickness of the side recrystallization region is less than 1mm, the cutting performance is good, and the alloy product does not contain lead and copper, so that the aluminum-silicon alloy not only meets the requirement of environmental protection, but also can improve the corrosion resistance of the alloy product, and can be applied to occasions with high requirements on corrosion resistance.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic flow chart of steps of a method for manufacturing an aluminum-silicon alloy according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

In one embodiment of the application, raw materials are weighed according to the mass percentage of the aluminum-silicon alloy, and the raw materials comprise 3.5% -4.5% of silicon (Si), 0.7% -1.0% of magnesium (Mg), 0.5% -0.7% of manganese (Mn), 0.03% -0.1% of titanium (Ti), and the balance of aluminum (Al). It should be noted that the balance aluminum (Al) means as an impurity component, and iron (Fe) is an inevitable impurity, which combines with Al and Si to form Al — Fe — Si and an alloy, which easily becomes a crack origin under stress, so that the mass percentage of the iron impurity is preferably 0.20% or less.

Referring to fig. 1, a schematic flow chart of steps of a method for manufacturing an aluminum-silicon alloy according to an embodiment of the present application is shown; as shown in the figure, the aluminum-silicon alloy is prepared according to the raw materials weighed above, and the preparation method 1 of the aluminum-silicon alloy comprises the following steps 101 to 104, wherein:

step 101, smelting raw materials. Adding the raw materials into a smelting furnace, executing a smelting process, and smelting the raw materials until the raw materials are completely melted to form molten aluminum, wherein Ti is mainly added in a titanium boron wire form in the casting process, so that nucleation is promoted, and cracking in the casting process is reduced.

And 102, casting and molding a bar stock. Preheating equipment used in the casting process, baking a launder, a degassing tank, a filter box and a die disc, then adopting a casting process, casting the raw materials into a die, cooling and solidifying the raw materials to form a bar stock, and firstly generating Mg in the solidification process of the raw materials/alloys₂Si can improve the strength of the alloy, and in the process of continuously reducing the temperature, excessive Si is separated out at a crystal boundary to form fine free Si particles, so that the chip breaking performance of the alloy can be obviously improved, the cutting performance of the product is improved, and a bar stock is formed after the alloy is cooled and solidified.

And 103, homogenizing the bar stock. Homogenizing the bar stock to eliminate the segregation of Si, Mg and other alloy elements in the alloy solidification process and to make acicular beta-phase Al easy to become a crack source₅Conversion of FeSi into skeletal alpha phase (Al)₈Fe₂Si), the homogenization treatment temperature is preferably set to 460-470 ℃, and specifically may be set to 460 ℃, 465 ℃ or 470 ℃, but not limited thereto.

And 104, extruding and forming a bar stock. The method comprises the steps of cutting a bar stock to a required length to form an aluminum alloy short bar, then placing the aluminum alloy short bar in an extruder heating furnace for preheating, wherein the aluminum alloy short bar is low in temperature, large in deformation resistance, low in mechanical property and high in blank temperature, and the extruded surface is easy to adhere, so that the surface is poor, the preheating temperature of the aluminum alloy short bar is preferably set to be 460 plus 470 ℃, and after preheating is completed, the aluminum alloy short bar is extruded and molded through a die to form an alloy product.

And 105, water cooling and aging treatment. After the alloy product is extruded and formed, the on-line water cooling is firstly carried out, and then the aging treatment is carried out at 175 +/-5 ℃/8h, so that the yield strength of the alloy product can reach 280-320 MPa.

The thickness of the side recrystallization region of the alloy product prepared by the preparation method 1 of the aluminum-silicon alloy in the embodiment is less than 1mm, and the alloy product does not contain lead and copper, so that the alloy product meets the requirement of environmental protection, and the corrosion resistance of the alloy product can be improved, so that the alloy product can be applied to occasions with higher requirements on corrosion resistance. Meanwhile, 3.5-4.5% of silicon in the alloy product is mainly eutectic of alpha + Si and Mg₂In the form of Si and free Si, Mg₂Si can enhance the strength of the alloy and enable the yield strength to be more than 280MPa, so that the alloy can be suitable for occasions with higher requirements on strength and hardness, a small amount of free Si can enable the aluminum alloy to be easy to break chips in the cutting process, the processing performance is good, and the surface smoothness after processing is high.

Meanwhile, the embodiment limits the mass percent of Mg in the alloy to be 0.70-1.0%, so that the problem that the extrusion property and the toughness of the aluminum alloy are deteriorated due to the fact that the content of Mg is lower than 0.70%, the strength of the aluminum alloy does not reach 310MPa, and the content of Mg exceeds 1.0% can be avoided. Meanwhile, the mass percentage of Mn in the alloy is limited to 0.5-0.7 percent in the embodiment, so that the problem that the excessive Mn content is too low to inhibit coarse grains and too high to enhance quenching sensitivity can be avoided.

The beneficial effects of the aluminum-silicon alloy and the preparation method thereof will be further described with reference to the following specific examples.

Example 1

1. Weighing raw materials according to the mass percent of the aluminum-silicon alloy, wherein the raw materials comprise 3.9-4.0% of Si, 0.6% of Mn, 0.75% of Mg, 0.06% of Ti and the balance of Al.

2. Adding the weighed raw materials into a smelting furnace, executing a smelting process, and smelting the raw materials until the raw materials are completely molten to form aluminum liquid;

3. electrically heating and baking the launder, the degassing tank and the filter box mould disc, then adopting a casting process, casting the raw materials into a mould, and forming a bar after the raw materials are cooled and solidified;

4. performing a homogenization procedure, wherein the homogenization treatment temperature is preferably set to 470 ℃, and performing homogenization treatment on the bar stock;

5. cutting the cast rod to a required length, placing the cast rod in an extruder heating furnace for preheating, setting the preheating temperature to 460 ℃, and after preheating is finished, performing extrusion molding through a die to form an alloy product;

6. after the alloy product is extruded and formed, carrying out online water cooling, and carrying out aging treatment at 175 +/-5 ℃/8h to obtain a final alloy product;

7. the thickness of a recrystallization zone of the tested alloy product is less than or equal to 0.5mm, the yield strength is 350MPa, the chip breaking performance during cutting is good, and the surface roughness after cutting is good.

Example 2

1. Weighing raw materials according to the mass percent of the aluminum-silicon alloy, wherein the raw materials comprise 3.75 percent of Si, 0.6 percent of Mn, 0.85 percent of Mg, 0.05 percent of Ti and the balance of Al.

2. Adding the weighed raw materials into a smelting furnace, executing a smelting process, and smelting the raw materials until the raw materials are completely molten to form aluminum liquid;

3. electrically heating and baking the launder, the degassing tank and the filter box mould disc, then adopting a casting process, casting the raw materials into a mould, and forming a bar after the raw materials are cooled and solidified;

4. performing a homogenization procedure, wherein the homogenization treatment temperature is preferably set to 470 ℃, and performing homogenization treatment on the bar stock;

5. cutting the cast rod to a required length, placing the cast rod in an extruder heating furnace for preheating, setting the preheating temperature to 460 ℃, and after preheating is finished, performing extrusion molding through a die to form an alloy product;

6. after the alloy product is extruded and formed, carrying out online water cooling, and carrying out aging treatment at 175 +/-5 ℃/8h to obtain a final alloy product;

7. the thickness of a recrystallization zone of the tested alloy product is less than or equal to 0.5mm, the yield strength is 330MPa, the chip breaking performance during cutting is good, and the surface roughness after cutting is good.

Example 3

1. Weighing raw materials according to the mass percent of the aluminum-silicon alloy, wherein the raw materials comprise 3.5-3.6% of Si, 0.6% of Mn, 0.95% of Mg, 0.06% of Ti and the balance of Al.

2. Adding the weighed raw materials into a smelting furnace, executing a smelting process, and smelting the raw materials until the raw materials are completely molten to form aluminum liquid;

3. electrically heating and baking the launder, the degassing tank and the filter box mould disc, then adopting a casting process, casting the raw materials into a mould, and forming a bar after the raw materials are cooled and solidified;

4. performing a homogenization procedure, wherein the homogenization treatment temperature is preferably set to 470 ℃, and performing homogenization treatment on the bar stock;

5. cutting the cast rod to a required length, placing the cast rod in an extruder heating furnace for preheating, setting the preheating temperature to 460 ℃, and after preheating is finished, performing extrusion molding through a die to form an alloy product;

6. after the alloy product is extruded and formed, carrying out online water cooling, and carrying out aging treatment at 175 +/-5 ℃/8h to obtain a final alloy product;

7. the thickness of a recrystallization zone of the tested alloy product is less than or equal to 0.5mm, the yield strength is 310MPa, the chip breaking performance during cutting is good, and the surface roughness after cutting is good.

According to the test data of the embodiment 1, the embodiment 2 and the embodiment 3, the yield strength of the alloy product prepared by the preparation method of the aluminum-silicon alloy can reach 280-320MPa, the cutting chip breaking performance is good, namely, the chip is easy to break in the cutting process, the processing performance is good, the surface roughness after cutting is good, and the surface smoothness after processing is high.

In summary, the application provides an aluminum-silicon alloy and a preparation method thereof, the yield strength of the prepared alloy product can reach 280-320MPa, the thickness of the side recrystallization region is less than 1mm, the cutting performance is good, and the alloy product does not contain lead and copper, so that the alloy product meets the environmental protection requirement, and the corrosion resistance of the alloy product can be improved, so that the alloy product can be applied to occasions with high corrosion resistance requirements.

The foregoing description shows and describes several preferred embodiments of the present application, but as aforementioned, it is to be understood that the application is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the application as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the application, which is to be protected by the claims appended hereto.