TW201907020A - Zinc-based alloy bead and manufacturing method thereof - Google Patents

Abstract

Provided is a zinc-based alloy shot that is composed of Al and the balance of Zn and inevitable impurities. The Al content in the zinc-based alloy shot is 1.0 to 6.0 mass%. The Vickers hardness of the zinc-based alloy shot is 50 to 100 HV. Further, Cu may be added to the zinc-based alloy shot as a trace amount addition element. The addition amount of the trace amount addition element may be 0.0001 to 0.25 mass% with respect to the shot of the zinc-based alloy.

Description

   Zinc-based alloy beads and manufacturing method thereof   

The present invention relates to a zinc-based alloy shot for blast processing and a manufacturing method thereof.

Sand blasting, which uses particles called shots to impact the workpiece to perform surface treatment (burr removal, rounding (chamfer R), surface roughness adjustment, matting processing, etc.) has been known for a long time. . The material of the beads is selected in accordance with the material of the workpiece and the processing purpose. For example, in the case of sandblasting a die casting product composed of an aluminum alloy, a magnesium alloy, or a zinc alloy, zinc beads are selected in consideration of the blasting removal ability and dust explosion resistance.

Patent Document 1 discloses a bead made of zinc. The Vickers hardness of the beads is in the range of 40 to 50 HV (in accordance with JIS Z2244), so the spraying removal ability is low.

Therefore, beads made of a zinc alloy were developed. For example, Patent Document 2 discloses a zinc-based alloy bead composed of zinc-manganese. However, manganese is the object of PRTR (pollutant release and transfer notification) system, which is not ideal from the viewpoint of safety and environmental protection.

    [Prior technical literature]         [Patent Literature]    

(Patent Document 1) Japanese Patent Laid-Open No. 63-312067

(Patent Document 2) Japanese Patent Laid-Open No. 2001-162538

In view of the foregoing, the present invention has as its object to provide an innovative zinc-based alloy bead with high blasting removal ability and long life, and a method for manufacturing the same.

According to the present invention, the following zinc-based alloy beads and a manufacturing method thereof are provided.

[1] A zinc-based alloy bead, wherein the zinc-based alloy bead is composed of aluminum and remaining zinc and unavoidable impurities, and the content of aluminum relative to the zinc-based alloy bead is 1.0 to 6.0% by mass, and The Vickers hardness of the zinc-based alloy beads is 50 to 100 HV.

[2] The zinc-based alloy beads according to the above item 1, wherein the Vickers hardness of the zinc-based alloy beads is 50 to 90 HV.

[3] A zinc-based alloy bead according to the item 1 or 2 above, wherein the zinc-based alloy bead is further added with copper as a trace element, and the amount of the trace-element added is relative to the zinc-based alloy bead. 0.0001 to 0.25% by mass.

[4] A zinc-based alloy bead according to any one of the above items 1 to 3, wherein the zinc-based alloy bead is a granular body having a diameter of 0.2 to 2.0 mm, or is (1: 0.8) ≦ (Diameter: length) ≦ (1: 1.3) cylinder.

[5] A zinc-based alloy bead according to any one of the above items 1 to 4, wherein the zinc-based alloy bead is a granular material, and the length in the longitudinal direction of the bead obtained from the projection view is a, When the maximum diameter in a direction orthogonal to the longitudinal direction is b, a / b of 60% or more of the beads is in a range of 1.0 to 1.3.

[6] A method for producing a zinc-based alloy bead, which is the method for producing a zinc-based alloy bead described in any one of the foregoing items 1 to 5, comprising: a scale as a raw material metal, zinc, aluminum, and if necessary, added Procedure for the weight of copper; Procedure for heating the aforementioned raw metal to become molten metal; Procedure for transferring the aforementioned molten metal to a molten metal holding container provided with a nozzle at the bottom; and dripping the molten metal through the aforementioned nozzle A procedure for falling into a liquid cooling medium; a procedure for solidifying the molten metal in the cooling medium to obtain granules; and a procedure for classifying the granules into a predetermined size, wherein the classification procedure is performed The diameter of the solidified molten metal is classified into 0.2 to 2.0 mm.

[7] A method for producing a zinc-based alloy bead, which is the method for producing a zinc-based alloy bead according to any one of the foregoing items 1 to 4, comprising: obtaining zinc, aluminum having a raw material metal; A procedure of a block made of an alloy of copper; a procedure of obtaining a wire of a predetermined wire diameter from the aforementioned block; and a procedure of cutting the aforementioned wire into a predetermined length, wherein the aforementioned procedure of obtaining the wire includes The process of rolling and stressing lumps.

[8] A method for producing a zinc-based alloy bead according to the item 7, wherein the procedure for cutting the wire is to cut the wire into (1: 0.8) ≦ (wire diameter: wire length) ≦ (1 : 1.3).

[9] A method for producing a zinc-based alloy bead according to item 7 or 8 above, wherein the procedure for obtaining the wire is to process the block into a wire diameter 0.4 ~ 2.0mm line.

According to the present invention, it is possible to provide zinc-based alloy beads with high jet milling removal ability and long life. In addition, containing a predetermined amount of copper can provide zinc-based alloy beads that not only suppress the occurrence of black stains on the workpiece, but also improve the blasting removal ability, life, and tensile strength.

FIG. 1 is a flowchart for explaining an embodiment of a method for manufacturing a zinc-based alloy bead according to the present invention.

Fig. 2 is a flowchart for explaining another embodiment of the method for producing a zinc-based alloy bead according to the present invention.

One aspect of the present invention is a zinc-based alloy bead. Zinc-based alloy beads are composed of aluminum and the rest of zinc and unavoidable impurities. The content of aluminum relative to the zinc-based alloy beads is 1.0 to 6.0% by mass. The Vickers hardness of the zinc-based alloy beads is 50 to 90 HV.

The zinc-based alloy bead of the present invention has higher hardness than zinc because of the addition of aluminum, and has high spray-removal ability. Moreover, since the impact resistance (toughness) is improved, the life is long. In addition, because aluminum is relatively inexpensive, zinc-based alloy beads with high jet milling removal ability and long life can be manufactured at low cost.

According to an embodiment of the present invention, copper may be further added to the zinc-based alloy beads as a trace addition element. In addition, it is possible to make the addition amount of the trace addition element account for 0.0002 to 0.25% by mass relative to the zinc-based alloy beads. Adding a small amount of copper can suppress the occurrence of black stains during sandblasting.

Another embodiment of the present invention is a zinc-based alloy bead as follows, that is, the aforementioned zinc-based alloy bead is made of aluminum, copper as a trace additive element, zinc as a remaining part, and unavoidable impurities. The composition has an aluminum content of 1.0 to 6.0% by mass relative to the zinc-based alloy beads, and a copper content of 0-0.25% by mass relative to the zinc-based alloy beads. The zinc-based alloy beads have a thickness of 0.2 to 2.0 mm. A granular body having a diameter of 1 mm or a cylinder having a ratio of (1: 0.8) ≦ (diameter: length) ≦ (1: 1.3), and the Vickers hardness of the zinc-based alloy beads is 50 to 90 HV.

One embodiment of the present invention is a method for manufacturing zinc-based alloy beads. This manufacturing method may include the following procedures (1) to (6).

(1) Procedures for measuring zinc, aluminum, and copper added as needed as raw materials.

(2) A procedure for heating the aforementioned raw metal to become molten metal.

(3) A procedure for transferring the aforementioned molten metal to a molten metal holding container provided with a pouring nozzle at the bottom.

(4) A procedure for dripping the molten metal into a liquid cooling medium through the pouring nozzle.

(5) A procedure for solidifying the molten metal in the cooling medium to obtain granular bodies.

(6) A procedure for classifying the aforementioned granular body into a predetermined size.

Moreover, the procedure of (6) may be to classify the diameter of the granular body into 0.2 to 2.0 mm.

Since aluminum is contained, the fluidity of the molten metal is improved. Therefore, the pouring nozzle is not blocked by the molten metal, and can be dropped well. In addition, if the diameter of the granular body is 0.2 to 2.0 mm, a granular body having a relatively uniform shape will be obtained.

One embodiment of the present invention is a method for manufacturing zinc-based alloy beads. This manufacturing method may include the following procedures (11) to (13).

(11) A procedure for obtaining a block having an alloy composition of zinc, aluminum, and copper added as needed as raw material metals.

(12) A procedure for obtaining a wire of a predetermined wire diameter from a block.

(13) A procedure for cutting a line into a predetermined length.

Further, the procedure for obtaining a wire may include a procedure for rolling a block and applying a stress.

Because aluminum is contained, the toughness of the alloy is improved. Therefore, when the block is rolled and processed into a linear shape, it will not be broken during processing. In addition, the mechanical properties can be improved by applying stress to the wire when rolling the lump.

According to an embodiment of the present invention, the procedure for obtaining a wire may be to process a block into a wire having a diameter between For a 0.4 ~ 2.0mm line, the procedure for cutting the line may be to cut the line into (1: 0.8) ≦ (line diameter: line length) ≦ (1: 1.3), or (1: 0.8) ≦ (line (The diameter of the wire: the length of the wire) ≦≦ (1: 1.2). If the diameter of the wire is between Above 0.4 mm, a line of mechanical strength required for sandblasting can be obtained. If in 2.0 mm or less, even when sandblasting a relatively soft workpiece such as an aluminum die-cast product, the workpiece will not be damaged more than necessary. In addition, by cutting the wire so that the ratio of the diameter to the length after cutting is within this range, sandblasting can be performed with less uneven quality in finishing.

Next, an embodiment of a zinc-based alloy bead and a manufacturing method thereof according to the present invention will be described with reference to the drawings. However, the present invention is not limited to this embodiment, but can be appropriately changed within an equal range. In the following description, "%" indicating the alloy composition means "mass%" unless otherwise specified.

The zinc-based alloy beads of one embodiment contain aluminum. Aluminum has a synergistic effect with zinc, so the Vickers hardness and impact resistance (toughness) of zinc-based alloys are improved. When the content of aluminum is too small, the effect of addition is not obtained, and when the content of aluminum is too large, the impact resistance of the zinc-based alloy tends to decrease because the effect of the physical properties of aluminum is too strong. In one embodiment, the content of aluminum (based on 100% of the total amount, the same applies hereinafter) is 1.0 to 6.0%, and may be 1.3 to 5.8% or 2.95 to 5.6%.

Copper is an element added as needed in order to improve the corrosion resistance of zinc-based alloy beads. The corrosion resistance is improved, and the surface of the workpiece can be prevented from being blackened when the zinc-based alloy beads are used for sandblasting. However, once too much copper is added, the impact resistance of the zinc-based alloy beads is reduced, so the addition amount is preferably a trace amount. In one embodiment, the amount of copper (based on 100% of the total amount, the same applies hereinafter) is 0 to 0.25%, may be 0.0001 to 0.25% or 0.0002 to 0.25%, or 0.0002 to 0.05. %.

Copper also has the effect of improving the Vickers hardness and impact resistance of zinc-based alloy beads. Adding a small amount of copper will not only have the aforementioned effect of suppressing the blackening of the workpiece, but also the effect of improving the blasting removal ability and life of zinc-based alloy beads.

Zinc-based alloy beads are also used for lower hardness workpieces such as die-cast products composed of aluminum alloy, magnesium alloy or zinc alloy. If the hardness of the zinc-based alloy beads is too low, the removal ability of the workpiece will be insufficient. If the hardness is too high, the design of the surface of the workpiece will be affected. Considering the physical properties of the workpiece and the purpose of spray grinding and removal, the Vickers hardness of zinc-based alloy beads is preferably 50 ~ 100HV, and it can also be 50 ~ 90HV or 70 ~ 90HV. The aluminum content or copper addition can be adjusted to make The hardness is within the above range.

The zinc-based alloy beads of one embodiment are composed of zinc and aluminum, or zinc and aluminum, and a small amount of copper, but may contain other unavoidable impurities. However, when the content of unavoidable impurities is high, the impact resistance is lowered and the life is reduced. Therefore, the content of unavoidable impurities is preferably as small as possible.

Therefore, in the zinc-based alloy beads, the content of aluminum relative to the zinc-based alloy beads is 1.0 to 6.0%, and the content of copper relative to the zinc-based alloy beads is 0.0001 to 0.25% by mass. Zinc-based alloy beads with a hardness of 50 to 100 HV are preferred.

Moreover, the content of aluminum relative to zinc-based alloy beads is 1.3 to 5.8%, the content of copper relative to zinc-based alloy beads is 0.0002 to 0.05% by mass, and the Vickers hardness of zinc-based alloy beads is 70 to 90 HV. Zinc-based alloy beads are more preferred.

Next, a method for producing a zinc-based alloy bead according to an embodiment will be described below with reference to FIG. 1.

S01: Procedure for weighing the raw materials of a scale

Measuring scale as the raw metal. For example, as the aluminum raw material (base metal), examples include: JISH2102 aluminum base metal special grade (99.90% or more) and JISH2111 (or ICS77.120.10) refined aluminum base metal special (99.995% or more), The first grade (more than 99.990%) and the second grade (more than 99.95%) are examples of copper raw materials (base metals): JISH2121 electrolytic copper base metals (more than 99.96%).

In addition, the raw material (base metal) of zinc as a matrix element is not particularly limited, and various grades specified by JISH2107 (or ISO725: 1981) can be used. Considering the quality stability of the beads, high-purity zinc base metals such as ordinary zinc base metals (more than 99.97%), the purest zinc base metals (more than 99.995%), and special zinc base metals (more than 99.99%) can be used for JISH2107.

S02: melting procedure

After the weighed metal is put into the crucible, the crucible is heated (for example, about 600 ° C). The metal is melted by heating to become a molten metal having a composition of zinc-aluminum or zinc-aluminum-copper.

S03: Molten metal moving program

The molten metal is put into a molten metal holding container. The molten metal holding container is provided with heating means, and can maintain the temperature of the molten metal so that it does not cool below the necessary temperature during the production of zinc-based alloy beads. The holding temperature of the molten metal at this time varies depending on the alloy composition and production scale, but it can be appropriately set within the range of 500 to 600 ° C.

A pouring nozzle for dripping molten metal is provided at the bottom of the molten metal holding container, and a cooling tank containing a cooling medium is arranged below the pouring nozzle. The cooling medium is liquid, and can be water or oil.

S04: Granulation program

The molten metal held in the molten metal holding container will drip from the pouring nozzle. During the period from the pouring nozzle to the cooling medium, it is spheroidized by the influence of surface tension. After reaching the cooling medium, the molten metal in contact with the cooling medium is rapidly cooled and directly solidifies in a spherical state.

The cooling medium rises in temperature due to contact with the molten metal, and this causes the rapid cooling of the molten metal to be prevented. Therefore, the cooling medium is maintained at a set temperature by a cooling means. For example, when setting the cooling temperature: when the cooling medium is water, it can usually be set below 60 ° C, and it can also be set within the range of 30 ~ 40 ° C.

S05: Classification procedure

Granular bodies of zinc-based alloys can accumulate on the bottom of the cooling medium. This granular material was recovered and dried with a dryer, and then classified with a classifier to obtain zinc-based alloy beads. The classification is performed so as to be a granular body having a predetermined particle size in accordance with the purpose of use of the zinc-based alloy beads.

Here, when the molten metal is dripped from the pouring nozzle, the shape of the droplet of the molten metal is not completely spherical, but is stretched and distorted in the dropping direction or even oval. Therefore, the shape of the obtained granular body, that is, the bead particle, is a slightly skewed spherical shape, a spheroidal shape, or a cylindrical shape with rounded corners. When the length of the bead obtained from the projection of such a bead is a, and the maximum diameter in a direction orthogonal to the length is b, a / b of 60% or more of the beads is preferably 1.0 to The range of 1.3 is better, and the range of 1.0 to 1.2 is better. Such a bead is close to a true sphere, and the shape variation is small, so a more uniform blasting removal effect will be obtained. The diameter of the granular body is in the range of 0.2 to 2.0 mm, and the ratio of beads with a / b values in the range of 1.0 to 1.3 or 1.0 to 1.2 is large, so classification can be performed so that the particle size falls within this range.

Therefore, in the zinc-based alloy beads, the content of aluminum relative to the zinc-based alloy beads is 1.0 to 6.0%, the content of copper relative to the zinc-based alloy beads is 0.0001 to 0.25% by mass, and the zinc-based alloy beads have 0.2 When the granular body with a diameter of ~ 2.0mm is obtained from the projection, the length in the longitudinal direction of the bead is a, and the maximum diameter in the direction orthogonal to the lengthwise direction is b. b is a zinc-based alloy bead having a Vickers hardness of 50 to 100 HV within a range of 1.0 to 1.3.

Moreover, the content of aluminum relative to zinc-based alloy beads is 1.3 to 5.8% by mass, the content of copper relative to zinc-based alloy beads is 0.0002 to 0.05%, and zinc-based alloy beads have a diameter of 0.2 to 2.0 mm. When the granular body has a length of a bead obtained from the projection and a maximum diameter of b in a direction orthogonal to the length direction, a / b of 60% or more of the beads is between 1.0 and 1.2. Within the range, and zinc-based alloy beads with a Vickers hardness of 70-90 HV are more preferred.

The method for producing the zinc-based alloy beads is not limited to the method described above. An example of a manufacturing method of another aspect is described below with reference to FIG. 2.

S11: Block manufacturing process

A block having a composition of zinc-aluminum or zinc-aluminum-copper is produced from a metal as a raw material. For example, a smelting method can be used to produce a cylindrical block called a billet from a metal as a raw material.

S12: Line manufacturing process

In this embodiment, a wire is manufactured from a compact. The billet is inserted into a plurality of dies, and the billet is drawn to reduce the diameter of the billet to a desired wire diameter due to plastic deformation to produce a wire. Since the ingot of this embodiment contains aluminum, it has good sliding properties with a mold. Therefore, it is possible to prevent the occurrence of wire breakage or micro-cracks during the manufacturing process.

In addition, the addition of copper as a trace element can increase the tensile strength of zinc-based alloys. In this way, it is possible to further prevent the occurrence of wire breakage or micro-cracks in the middle of the manufacturing line.

With the addition of aluminum and copper, the compact made of zinc-based alloy can pass through the mold well, so the zinc-based alloy can be stressed by plastic deformation and friction with the mold. As a result, mechanical properties (such as toughness) required for the beads can be improved. For example, the mechanical properties can be adjusted by changing the drawing speed of the billet or the diameter and number of molds.

Although the method of making the wire diameter thinner will apply stress to the zinc-based alloy to improve its mechanical properties, if it is made too detailed, it will be damaged due to this processing. In addition, if the wire diameter is too large, the surface of the workpiece may be damaged if the workpiece is not subjected to sufficient stress or is subjected to sandblasting. Based on the above arguments, the diameter of the wire can be made between Within the range of 0.4 ~ 2.0mm.

S13: Cut-off procedure

The obtained thread was cut in a predetermined length along the length direction to obtain a pellet. When the difference between the length and the diameter of the granular material is large, unevenness of the dressing quality of the workpiece after the blasting process may occur. With this in mind, the line can be cut into segments that satisfy (1: 0.8) ≦ (line diameter: line length) ≦ (1: 1.3), or (1: 0.8) ≦ (line diameter: The length of the line) is ≦ (1: 1.2) to cut the line.

S14: Rounding procedure

The obtained pellets are cylindrical, so there are corners. This corner will cause damage to the workpiece during sandblasting. Therefore, the corner can be rounded by spraying the granular object on the wall in advance. This procedure can also be omitted depending on the physical properties of the workpiece or the purpose of sandblasting.

Therefore, in the zinc-based alloy beads, the content of aluminum relative to the zinc-based alloy beads is 1.0 to 6.0%, and the content of copper relative to the zinc-based alloy beads is 0.0001 to 0.25%. The zinc-based alloy beads have (1 : 0.83) ≦ (diameter: length) ≦ (1: 1.25), the length of the beads in the length direction obtained from the projection is a, and the maximum diameter in the direction orthogonal to the length is b. In some cases, a / b of more than 60% of the beads is in the range of 1.0 to 1.3, and zinc-based alloy beads having a Vickers hardness of 50 to 100 HV are preferred.

Moreover, the content of aluminum relative to the zinc-based alloy beads is 1.3 to 5.8%, and the content of copper relative to the zinc-based alloy beads is 0.0002 to 0.25%. The zinc-based alloy beads have (1: 0.83) ≦ (diameter : Length) ≦ (1: 1.25). When the length of the beads in the length direction obtained from the projection is a and the maximum diameter in the direction orthogonal to the length is b, 60% or more The a / b of the beads is in the range of 1.0 to 1.2, and the zinc-based alloy beads with a Vickers hardness of 70-90 HV are more preferred.

Next, the results obtained by evaluating the zinc-based alloy beads of one embodiment will be described.

    [Example]    

Zinc-based alloy beads were produced from the aluminum and copper and zinc base metals weighed at the ratios shown in Table 1 to be described later in the procedures S01 to S05 (type A) or S11 to S14 (type B).

Type A: Manufactured by the procedures S01 to S05 of the above-mentioned manufacturing method, and classified into zinc-based alloy beads having an average particle diameter of 0.8 mm and the aforementioned a / b of 1.0 to 1.3.

Type B: a zinc-based alloy bead manufactured by procedures S11 to S14 and having a wire diameter of 0.8 mm.

The following evaluation tests were performed on these zinc-based alloy beads.

100 kg of zinc-based alloy beads were put into a sand blasting machine (DZB type: manufactured by Shinto Industry Co., Ltd.), and an aluminum alloy die-casting part (surface hardness: 100 HV) as a workpiece was subjected to sand blasting to evaluate performance. The spraying speed of the zinc-based alloy beads was 53 m / s.

The evaluation items include "consumption", "flash removal ability", and "dressing quality", and are performed as follows.

<Consumption>

This corresponds to the evaluation of life and even toughness (impact resistance). The amount which was blasted for 8 hours using zinc-based alloy beads and became fine powder and was lost was evaluated as "bead consumption" on the following criteria.

◎: 0.06kg / (h‧HP) or less

○: 0.06kg / (h‧HP) ~ 0.08kg / (h‧HP)

△: 0.08kg / (h‧HP) ~ 0.10kg / (h‧HP)

×: 0.10kg / (h‧HP) or more

<Flash removal ability>

This corresponds to the evaluation of the blasting removal ability and even the blasting ability. The blast processing time required to completely remove the burrs was measured and evaluated using the following criteria. The removal of burrs was evaluated visually.

◎: Remove burrs with a sandblasting time of 30 seconds

○: Removes burrs with a sandblasting time of 60 seconds

△: Remove burrs with a sandblasting processing time of 90 seconds

×: The burr was not removed even with the blasting processing time of 90 seconds

<Dressing quality>

The surface of the workpiece after sandblasting was observed, and evaluation was performed with the following criteria (visual evaluation).

◎: silvery white luster

○: Slightly blackened

△: Blackening

Each evaluation result is shown in Table 1. The "diameter-length ratio" in the table indicates the "diameter of the wire: the length of the wire" after the wire was cut in the type B zinc-based alloy beads.

<Evaluation of consumption>

The two types of zinc-based alloy beads are the same, and Examples 1 to 10 in which the amount of aluminum is in the range of 1.0 to 6.0% have no less than △ evaluation under any conditions. In addition, the same applies to the case where copper is added in a range of 0.0001 to 0.25% in a trace amount, and evaluations of Δ or more are made regardless of the conditions. Here, although the Δ evaluation is worse than the ○ evaluation, there is no practical problem, which means that the evaluation of ○ or more can be obtained by optimizing the injection conditions (ejection speed, particle size, etc.). From this, it can be seen that in Examples 1 to 10, the evaluation of the consumption amount was good.

In the case where the composition of the type B zinc-based alloy beads is similar to that of the type A zinc-based alloy beads, the evaluation of the consumption amount is equivalent or a better evaluation. This is conceivable because the process of applying stress is included in the manufacturing process of the B-type zinc-based alloy beads, so the mechanical properties of the zinc-based alloy beads are improved, and the impact resistance is thereby improved.

Comparative Example 3 in which the amount of aluminum was too much and Comparative Example 4 in which the amount of copper was too large were evaluated as ×. In both cases, it is thought that the impact resistance was deteriorated due to the excessive addition of aluminum and copper.

<Flash removal ability>

Both types of zinc-based alloy beads are the same. Examples 1 to 10 in which the amount of aluminum added is in the range of 1.0 to 6.0% can be seen that the evaluation tends to decrease if the amount of aluminum increases, but no matter what the conditions All have △ or more evaluations. In addition, the same applies to the case where copper is added in a range of 0.0001 to 0.25% in a trace amount, and evaluations of Δ or more are made regardless of the conditions. Here, although the Δ evaluation is worse than the ○ evaluation, there is no practical problem, which means that the evaluation of ○ or more can be obtained by optimizing the injection conditions (ejection speed, particle size, etc.). From this, it can be seen that in Examples 1 to 10, the evaluation of the burr removal ability was good.

In the case where the composition of the type B zinc-based alloy beads is similar to that of the type A zinc-based alloy beads, the evaluation of the burr removal ability is equal to or better. This is conceivable because the process of applying stress is included in the manufacturing process of the B-type zinc-based alloy beads, so the mechanical properties of the zinc-based alloy beads are improved.

Comparative Example 1 in which aluminum was not added and Comparative Example 2 in which the amount was too small were evaluated as ×. This is thought to be because the Vickers hardness is lower than that of the workpiece.

In Comparative Examples 5 and 6 where the diameter-length ratio was too small or too large, the evaluations were both ×. The reason can be thought that the impact of the zinc-based alloy beads on the workpiece may be uneven, resulting in reduced burr removal ability.

<Dressing quality>

The two types of zinc-based alloy beads are the same. Examples 3, 4, 7, 8, 9, 10 were added in a trace amount of copper in the range of 0.0001 to 0.25%, regardless of the conditions. It means that adding a small amount of copper will improve the dressing quality.

In addition, in Examples 1, 2, 5, and 6 in which copper was not added, the evaluation was △ or ○. When viewed together with the results of Comparative Example 1, it can be seen that the addition of aluminum can also improve the dressing quality. This is thought to be because the burr removal ability is improved and the time until the end of the blasting process is shortened, so the chance of the workpiece being exposed to the jet of zinc-based alloy beads is reduced.

    (Industrial availability)    

The zinc-based alloy beads of one embodiment can be applied to the removal of burrs and burrs of non-ferrous metal parts such as aluminum die-casting products and aluminum casting products, sand cleaning of cast products, and mold coating agents or mold release agents for burning. Sand blasting for the purpose of removing, oxidizing film or flow marks, sealing treatment, etc.

Claims (9)

    A zinc-based alloy bead, which is composed of aluminum and the rest of zinc and unavoidable impurities, wherein the aluminum content is 1.0 to 6.0% by mass relative to the zinc-based alloy bead, Vickers hardness is 50 ~ 100HV.         According to the zinc-based alloy bead described in item 1 of the scope of patent application, the Vickers hardness of the zinc-based alloy bead is 50 to 90 HV.         The zinc-based alloy beads according to item 1 or 2 of the scope of the patent application, wherein the zinc-based alloy beads are further added with copper as a trace addition element, and the amount of the trace-addition elements is relative to the zinc-based alloy beads. It accounts for 0.0001 to 0.25% by mass.         The zinc-based alloy bead according to any one of claims 1 to 3, wherein the zinc-based alloy bead is a granular body having a diameter of 0.2 to 2.0 mm, or has a diameter of (1: 0.8). A cylinder with a ratio of ≦ (diameter: length) ≦ (1: 1.3).         The zinc-based alloy bead according to any one of claims 1 to 4, wherein the zinc-based alloy bead is a granular body, and the length in the longitudinal direction of the bead obtained from the projection view is a When the maximum diameter in the direction orthogonal to the length direction is b, a / b of 60% or more of the beads is in the range of 1.0 to 1.3.         A method for manufacturing a zinc-based alloy bead, which is the method for manufacturing a zinc-based alloy bead according to any one of claims 1 to 5, and includes: measuring scale zinc, aluminum as a raw metal, and adding as needed A procedure of copper; a procedure of heating the aforementioned raw metal to become molten metal; a procedure of transferring the aforementioned molten metal to a molten metal holding container provided with a pouring nozzle at the bottom; and causing the aforementioned molten metal to drip into the liquid through the aforementioned pouring nozzle A procedure in a cooling medium; a procedure in which the molten metal is solidified in the cooling medium to obtain granules; and a procedure in which the granules are classified into a predetermined size, wherein the classification procedure is performed by The diameter of the molten metal is classified into 0.2 ~ 2.0mm.         A method for manufacturing a zinc-based alloy bead, which is the method for manufacturing a zinc-based alloy bead described in any one of claims 1 to 4, including: obtaining zinc, aluminum having a raw material metal, and adding as needed A procedure for obtaining a block made of copper alloy; a procedure for obtaining a wire with a predetermined wire diameter from the aforementioned block; and a procedure for cutting the aforementioned wire into a predetermined length, wherein the aforementioned procedure for obtaining the wire includes the step of The process of rolling and applying stress to objects.         The method for manufacturing a zinc-based alloy bead according to item 7 of the scope of the patent application, wherein the aforementioned procedure for cutting the wire is to cut the wire into (1: 0.8) ≦ (wire diameter: wire length) ≦ ( 1: 1.3).     The method for manufacturing a zinc-based alloy bead according to item 7 or 8 of the scope of patent application, wherein the aforementioned procedure for obtaining a wire is to process a block into a wire diameter 0.4 ~ 2.0mm line.