阅读说明：本技术 一种锌合金及其制造方法 (Zinc alloy and manufacturing method thereof ) 是由 吴健 于云峰 古文全 薛涛 梁寅 李英 于 2019-11-29 设计创作，主要内容包括：本发明公开了一种锌合金及其制造方法,该锌合金各元素含量为：Al4%-7%,Cu0.5%-1.5%,Ti0.4%-0.7%,B0.07%-0.1%,Mg0.02%-0.025%、其它0.1%-1%、Zn余量；该方法包括：①将纯铝加热至熔融状态后喷涂在坩埚内表面,将过滤结构固定在内表面侧面；②将锌合金原材料放入坩埚中,抽真空然后升温至原材料完全熔化,获得熔池；③开启石墨搅拌装置,持续加入精炼剂,获得纯化熔池；④将纯化熔池变质后采用降温挤压工艺浇铸成型,获得待处理锌合金锭；⑤将待处理锌合金锭球化退火处理,即获得所需锌合金。本发明纯净度高、大尺寸枝晶偏析少、整体晶粒度细化均匀、原始组织多共晶少枝晶。(The invention discloses a zinc alloy and a manufacturing method thereof, wherein the content of each element of the zinc alloy comprises 4% -7% of Al, 0.5% -1.5% of Cu, 0.4% -0.7% of Ti, 0.07% -0.1% of B, 0.02% -0.025% of Mg0.1% -1% of other elements and the balance of Zn, the method comprises the steps of heating ① pure aluminum to a molten state, spraying the pure aluminum on the inner surface of a crucible, fixing a filter structure on the side surface of the inner surface, ② putting a zinc alloy raw material into the crucible, vacuumizing, heating until the raw material is completely molten, obtaining a molten pool, ③ starting a graphite stirring device, continuously adding a refining agent, obtaining a purified molten pool, ④ performing modification on the purified molten pool, performing casting molding by adopting a cooling extrusion process, obtaining a zinc alloy ingot to be treated, ⑤ performing spheroidizing treatment on the zinc alloy ingot to be treated, and obtaining the required zinc alloy.)

1. A method for manufacturing a zinc alloy, characterized by comprising the steps of;

1) preparation before production

① raw material preparation, preparing 99 to 99.35 parts of Zn-Al4 alloy, 0.55 to 0.9 part of AlTi5B intermediate alloy and ZnCl₂0.05 to 0.15 portion of refining agent, 0.7 to 0.8 portion of enough pure aluminum and 0.7 portion of alterant;

② preparing equipment and tooling, namely preparing vacuum melting equipment with an air passage, a graphite stirring device and a melting crucible arranged inside, a protective atmosphere furnace, the graphite crucible with a mechanical stirring device, and a filtering structure consisting of an alumina ceramic structural member, a primary coarse screen made of alumina ceramic and an online filtering screen made of carbon fiber ceramic composite material with the back lining on the outer surface of the primary coarse screen;

2) smelting of raw materials

① heating pure aluminum to a molten state, spraying the molten liquid on the inner surface of the crucible in the vacuum melting equipment to a thickness of 1.5mm-2mm, and fixing the filtering structure on the side surface of the inner surface of the melting crucible to obtain a crucible for use;

② putting Zn-Al4 alloy prepared in step ① in stage 1) into the crucible to be used prepared in step ①, and vacuumizing to 1 × 10 of vacuum degree^-3Pa-1×10^-4Pa, then raising the temperature to 550-560 ℃, keeping the temperature until the raw materials are completely melted, and sequentially adding the AlTi5B intermediate alloy prepared in the step ① of the stage 1) and ZnCl₂Stirring until all additives are uniformly mixed after all additives are melted, and standing for 10-20 min under the condition of heat preservation to obtain a molten pool;

③ starting a graphite stirring device, stirring the molten pool obtained in the step ② at a speed of 50-60 rpm, adding the alterant prepared in the step 1) of ① into the molten pool, and continuously stirring for 15-20 min to obtain a purified molten pool;

④, casting and molding the purified molten pool obtained in the step ③ by adopting a cooling extrusion process to obtain a zinc alloy ingot to be treated;

⑤, heating the zinc alloy ingot to be processed obtained in the step ④ to 305-310 ℃, preserving heat for 2-2.5 h, cooling to 120 ℃ along with the furnace after heat preservation is finished, and then discharging and air cooling to obtain the zinc-based alloy mother ingot with low segregation and high filling performance.

2. The method for producing a zinc alloy according to claim 1, wherein: wherein the alterant is a compound salt alterant consisting of K2TiF6 and KBF4 in a mass ratio of 4: 1.

3. The method for producing a zinc alloy according to claim 1, wherein: the online filtering device is characterized in that the number of the filtering structures is two, the filtering structures are symmetrically fixed on the side surface of the inner surface of the smelting crucible, the normals of the opening end surfaces of the online filtering screens integrated on the two filtering structures face the same direction, and the two normals are parallel.

4. A zinc alloy characterized by: the zinc alloy comprises the following elements in percentage by weight: al 4-7%, Cu 0.5-1.5%, Ti 0.4-0.7%, B0.07-0.1%, Mg0.02-0.025%, others 0.1-1%, and Zn in balance.

Technical Field

The invention relates to the technical field of zinc alloy smelting, in particular to a zinc alloy and a manufacturing method thereof.

Background

The zinc alloy is an alloy formed by adding other elements on the basis of zinc. The common alloy elements comprise low-temperature zinc alloy such as aluminum, copper, magnesium, cadmium, lead, titanium and the like. The zinc alloy has low melting point, good fluidity, easy fusion welding, brazing and plastic processing, corrosion resistance in the atmosphere and convenient recovery and remelting of residual wastes; however, the creep strength is low, and dimensional change due to natural aging is likely to occur.

In addition to the above-mentioned intrinsic performance drawbacks, the zinc alloys of the prior art have the following technical problems: 1. most zinc alloys are manufactured due to low melting cost (mainly low melting temperature, low energy consumption and low raw material cost), so that the zinc alloys have more impurities and can only be used for decorative application but not structural and functional application; 2. in the prior art, even high-end functional zinc alloy has large cast structure dendrite generally with large size and obvious segregation; 3. the zinc alloy has low melting point, and the prior art generally adopts 60-80 ℃ superheat degree for melting, so that although the melting cost is reduced and the melting efficiency is improved, the original cast ingot grains are too coarse and uneven in grain size, and the precision processing, heat treatment and final application of the zinc alloy are limited; 4. in the prior art, zinc alloy mother ingots are all of a structure in which a plurality of dendritic crystals (columnar single crystals) are embedded in a staggered manner, and a small amount of eutectic is doped among the crystals, but according to the prior art, the larger the eutectic structure proportion is, the higher the obtained fluidity is, and the better the casting and filling performance is.

Therefore, there is a need for a zinc alloy with high purity, less dendrite segregation, uniform grain size refinement, and more eutectic and less dendrite in the original structure, and a method for manufacturing the same.

Disclosure of Invention

The invention aims to provide a zinc alloy with high purity, less segregation of large-size dendrites, uniform and refined integral grain size, more eutectic primary tissues and less dendrites and a manufacturing method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme: a manufacturing method of zinc alloy comprises the following steps;

1) preparation before production

① raw material preparation, preparing 99 to 99.35 parts of Zn-Al4 alloy, 0.55 to 0.9 part of AlTi5B intermediate alloy and ZnCl₂0.05 to 0.15 portion of refining agent, 0.7 to 0.8 portion of enough pure aluminum and 0.7 portion of alterant;

② preparing equipment and tooling, namely preparing vacuum melting equipment with an air passage, a graphite stirring device and a melting crucible arranged inside, a protective atmosphere furnace, the graphite crucible with a mechanical stirring device, and a filtering structure consisting of an alumina ceramic structural member, a primary coarse screen made of alumina ceramic and an online filtering screen made of carbon fiber ceramic composite material with the back lining on the outer surface of the primary coarse screen;

2) smelting of raw materials

① heating pure aluminum to a molten state, spraying the molten liquid on the inner surface of the crucible in the vacuum melting equipment to a thickness of 1.5mm-2mm, and fixing the filtering structure on the side surface of the inner surface of the melting crucible to obtain a crucible for use;

② putting Zn-Al4 alloy prepared in step ① in stage 1) into the crucible to be used prepared in step ①, and vacuumizing to 1 × 10 of vacuum degree^-3Pa-1×10^-4Pa, then raising the temperature to 550-560 ℃, keeping the temperature until the raw materials are completely melted, and sequentially adding the AlTi5B intermediate alloy prepared in the step ① of the stage 1) and ZnCl₂Stirring until all additives are uniformly mixed after all additives are melted, and standing for 10-20 min under the condition of heat preservation to obtain a molten pool;

③ starting a graphite stirring device, stirring the molten pool obtained in the step ② at a speed of 50-60 rpm, adding the alterant prepared in the step 1) of ① into the molten pool, and continuously stirring for 15-20 min to obtain a purified molten pool;

④, casting and molding the purified molten pool obtained in the step ③ by adopting a cooling extrusion process to obtain a zinc alloy ingot to be treated;

⑤, heating the zinc alloy ingot to be processed obtained in the step ④ to 305-310 ℃, preserving heat for 2-2.5 h, cooling to 120 ℃ along with the furnace after heat preservation is finished, and then discharging and air cooling to obtain the zinc-based alloy mother ingot with low segregation and high filling performance.

In the above method for manufacturing zinc alloy, the modifier is a compound salt modifier consisting of K2TiF6 and KBF4 in a mass ratio of 4: 1.

In the manufacturing method of the zinc alloy, the two filter structures are symmetrically fixed on the side surface of the inner surface of the melting crucible, and the normals of the opening end surfaces of the on-line filter screens integrated on the two filter structures face to the same direction and are parallel to each other.

A zinc alloy comprises the following elements in percentage by weight: al 4-7%, Cu 0.5-1.5%, Ti 0.4-0.7%, B0.07-0.1%, Mg0.02-0.025%, others 0.1-1%, and Zn in balance.

Compared with the prior art, the invention has the advantages that (1) the addition of the master alloy, the refining agent and the alterant of the invention and the special online filtering structure of the invention are assisted, so that the invention finally obtains 4-5 grades of crystal grains, the dendrite is reduced, the spacing between dendritic crystal reticulocyte layers is reduced, the thickness of lamellar tissue is reduced, heterogeneous crystal nucleus is increased, η -Zn refined casting high-purity high-fluidity zinc alloy, (2) the invention improves the crystallizer structure and increases the online filtering structure, therefore, the invention does not need manual slag removal and slag removal agent addition, and the slag removal efficiency, the degassing efficiency and the cleaning degree are all higher than the prior art, so the invention has higher purity than the prior art, (3) the invention ensures that the crystal grain size of the original ingot casting is not coarser than 4 grade by refining agent with high quality and compounding and having metamorphic function and shorter smelting time through smelting compounding at higher speed, the invention ensures that the crystal grain size of the original ingot casting is not coarser than 4 grade, the invention has basic application, (4) the advantages of being completely different from the prior art smelting process parameters, equipment, the prior art, the process, the refining process, the cooling mode and the subsequent cooling mode, the invention can further obtain the refined eutectic crystal grain size of the eutectic crystal phase and the refined eutectic crystal grain size of the invention by adopting the improved and the improved refining process of the invention, the invention can be suitable for the secondary eutectic crystal grain size of the slag removal of the refining of the invention, and the invention, the invention can be suitable for the secondary eutectic crystal grain size of the invention, and the secondary eutectic crystal grain size of the invention, and the invention.

Drawings

FIG. 1 shows the final metallographic structure according to the invention;

FIG. 2 is an as-cast texture map of the present invention;

FIG. 3 is an as-cast structure diagram of original Zn-Al 4;

FIG. 4 is a view of the deteriorated tissue of the present invention;

FIG. 5 is a structural diagram of original Zn-Al4 after modification

FIG. 6 is a structural diagram of the AlTi-5B master alloy of the present invention after deterioration when the lower limit of the addition amount is 0.55%;

FIG. 7 is a structural diagram of the AlTi-5B intermediate alloy of the present invention after being modified by adding 0.9% of the upper limit;

FIG. 8 is a structural diagram of a modified AlTi-5B master alloy without addition of AlTi-5B;

FIG. 9 is a schematic view of a melting crucible with a fixed filter structure;

FIG. 10 is a schematic view of a bidirectional stirring melting crucible with two fixed filter structures.

Detailed Description