TWI771436B - Zinc-based alloy shot and manufacturing method thereof - Google Patents

Abstract

Provided is a zinc-based alloy shot, the zinc-based alloy shot being composed of Al and Mg with the balance being Zn and inevitable impurities, the Al content being 0.05 to 0.20 mass% and the Mg content being 0.001 to 0.20 mass% with respect to the zinc-based alloy shot, and the Vickers hardness of the zinc-based alloy shot being 80 to 150 HV. Further, in the zinc-based alloy shot, Cu may be added as a trace addition element, and the addition amount of the trace addition element may be 0.0002 to 0.01 mass% with respect to the zinc-based alloy shot.

Description

Zinc-based alloy beads and method for producing the same

The present invention relates to a zinc-based alloy shot for blast processing and a method for producing the same.

Sandblasting is a long-known technique for surface treatment (burr removal, rounding (R-angle), surface roughness adjustment, matting, etc.) of the workpiece by impacting particles called shot on the workpiece. . The material of the beads is selected according to 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 the resistance to dust explosion.

Patent Document 1 discloses a bead made of zinc. The Vickers hardness of this bead is 40 to 50 HV (as specified by JIS Z2244), so the blasting removal ability is low.

Therefore, beads composed of zinc alloys were developed. For example, Patent Document 2 discloses a zinc-based alloy bead composed of zinc-manganese. However, manganese is an object of the PRTR (Pollutant Release and Transfer Reporting) system, which is not ideal from the viewpoint of safety and environmental protection.

[Prior Art 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 above, the present invention aims to provide an innovative zinc-based alloy bead with high blast-removal ability and long service life, and its blast-removal ability can be adjusted according to the properties of the workpiece and the blast-removal purpose, and a method for producing the same.

According to the present invention, the following zinc-based alloy beads and methods for producing the same are provided.

[1] A zinc-based alloy bead, wherein the zinc-based alloy bead is composed of aluminum and magnesium, the remainder of zinc and inevitable impurities, and the content of aluminum relative to the zinc-based alloy bead is 0.05 to 0.20 mass % And the content of magnesium is 0.001 to 0.20 mass %, and the Vickers hardness of the aforementioned zinc-based alloy beads is 80 to 150 HV.

[2] The zinc-based alloy beads according to the above item 1, wherein the zinc-based alloy beads are further added with copper as a trace addition element, and the addition amount of the trace addition element is 0.0002 to 0.0002 to 0.01 mass %.

[3] A zinc-based alloy bead according to item 1 or 2, wherein the zinc-based alloy bead is a granular body having a diameter of 0.2 to 2.0 mm, or has (1:0.8)≦(diameter:length )≦(1:1.3), and the Vickers hardness of the zinc-based alloy beads is 80 to 150HV.

[4] A zinc-based alloy bead according to item 1 or 2, wherein the zinc-based alloy bead is a granular body, and the length in the longitudinal direction of the bead determined from the projection diagram is a, and the length in the longitudinal direction of the bead is a. When the maximum diameter in the orthogonal direction is b, the a/b of more than 60% of the beads is in the range of 1.0 to 1.3.

[5] A method for producing zinc-based alloy beads, which is the method for producing zinc-based alloy beads according to any one of the above items 1 to 4, comprising: weighing zinc, aluminum, and magnesium as raw material metals, and as needed Procedure of adding weight of copper; procedure of heating the aforementioned raw metal to become molten metal; procedure of transferring the aforementioned molten metal to a molten metal holding container equipped with a nozzle at the bottom; procedure of passing the aforementioned molten metal through the aforementioned nozzle A process of dropping into a liquid cooling medium; a process of solidifying the molten metal in the cooling medium to obtain granular bodies; a process of classifying the solidified granular bodies into a predetermined size; and adjusting the classification The procedure of hardness of the subsequent granular body, wherein the procedure of classification is performed to classify the diameter of the solidified molten metal into 0.2 to 2.0 mm.

[6] A method for producing zinc-based alloy beads, which is the method for producing zinc-based alloy beads according to any one of the above items 1 to 3, comprising: obtaining zinc, aluminum, and magnesium as raw material metals, and as needed A procedure for forming a bulk of an alloy of added copper; a procedure for obtaining a wire of a predetermined diameter from the bulk; and a procedure for cutting the wire into a predetermined length, wherein the procedure for obtaining the wire is Contains the process of rolling and stressing the block.

[7] A method for producing a zinc-based alloy bead according to Item 6, wherein the procedure for cutting the wire is to cut the wire so that (1:0.8)≦(diameter of wire:length of wire)≦(1 : 1.3).

0.4至2.0mm之線。 [8] A method for producing a zinc-based alloy bead according to item 6 or 7, wherein the procedure for obtaining the wire is to process the block into a wire with a diameter of

0.4 to 2.0mm wire.

According to the present invention, it is possible to provide zinc-based alloy beads with high blasting removal ability and long life, and the blasting removal ability can be adjusted according to the properties of the workpiece and the blasting removal purpose. In addition, by containing a predetermined amount of copper, it is possible to provide zinc-based alloy beads that not only suppress the occurrence of black stains on the workpiece, but also have improved blast removal capability, life, and tensile strength.

S01 to S06, S11 to S14‧‧‧Programs

Fig. 1 is a flow chart for explaining one embodiment of the method for producing zinc-based alloy beads of the present invention.

Fig. 2 is a flow chart for explaining another embodiment of the method for producing the zinc-based alloy beads of the present invention.

One aspect of the present invention is zinc-based alloy beads. Zinc-based alloy beads are composed of aluminum and magnesium and the remainder of zinc and inevitable impurities. Also, the content of aluminum with respect to the zinc-based alloy beads is 0.05 to 0.20 mass %, and the content of magnesium is 0.001 to 0.20 mass %. In addition, the Vickers hardness of the zinc-based alloy beads is 80 to 150 HV.

One aspect of the present invention is the zinc-based alloy beads, which have higher hardness than zinc due to the addition of aluminum, and high blast-grinding removal ability. Also, because the impact resistance (toughness) is improved, the life is long. In addition, since aluminum is relatively inexpensive, zinc-based alloy beads with high blast removal capability and long life can be produced at low cost.

In addition, since magnesium is added, the blasting removal ability of the zinc-based alloy beads can be adjusted according to the physical properties of the workpiece and the blasting removal purpose.

In one embodiment of the present invention, copper can be added to the zinc-based alloy beads as a trace addition element. Also, the addition amount of the trace additive element may be 0.0002 to 0.01 mass % with respect 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 zinc-based alloy bead is composed of aluminum, magnesium, copper as a trace addition element, and zinc as the remaining part and inevitable The impurity is composed of 0.05 to 0.20 mass % of aluminum relative to the aforementioned zinc-based alloy beads, 0.001 to 0.20 mass % relative to the aforementioned zinc-based alloy beads of magnesium content, relative to the aforementioned zinc-based alloy beads. The content is 0 to 0.05 mass %, and the zinc-based alloy beads are granular bodies having a diameter of 0.2 to 2.0 mm, or those having a ratio of (1:0.8)≦(diameter:length)≦(1:1.3) cylindrical, and the Vickers hardness of the aforementioned zinc-based alloy beads is 80 to 150 HV.

One embodiment of the present invention is a method for producing zinc-based alloy beads. This manufacturing method may include the following procedures (1) to (7).

(1) A procedure of weighing the weights of zinc, aluminum, magnesium, and copper added as necessary as raw materials.

(2) A process of heating the aforementioned raw metal to become molten metal.

(3) A procedure of transferring molten metal to a molten metal holding container equipped with a nozzle at the bottom.

(4) A process of dropping the molten metal into a liquid cooling medium through a nozzle.

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

(6) A procedure for classifying granular bodies into predetermined sizes.

(7) Procedure for adjusting the hardness of the classified granular body.

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

Because of the inclusion of aluminum, the fluidity of the molten metal increases. Therefore, the pouring nozzle is not blocked by the molten metal and can be dripped satisfactorily. In addition, if the granular body is 0.2 to 2.0 mm in diameter, a granular body with a relatively uniform shape will be obtained.

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

(11) A procedure for obtaining a lump having an alloy composition of zinc, aluminum, magnesium, and optionally added copper as raw metals.

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

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

Also, the process of obtaining the wire may include the process of rolling and stressing the block.

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

0.4至2.0mm之線，將線切斷之程序可為將線切成(1：0.8)≦(線的直徑：線的長度)≦(1：1.3)、或(1：0.8)≦(線的直徑：線的長度)≦(1：1.2)。若線的直徑在

0.4mm以上，就可得到具有噴砂加工所需的機械性的強度之線。若在

2.0mm以下，則即使在對例如鋁壓鑄製品等較柔軟的工件進行噴砂加工之情況，也不會對工件造成必要程度以上的損傷。另外，將線切成使得切成段後的線的直徑與長度之比在該範圍內，可進行修整(finishing)品質較少參差之噴砂加工。 In one embodiment of the present invention, the procedure for obtaining the wire may be to process the block into a wire with a diameter of

0.4 to 2.0mm wire, the procedure of cutting the wire can be to cut the wire into (1:0.8)≦(Wire diameter:Wire length)≦(1:1.3), or (1:0.8)≦(Wire diameter: the length of the wire)≦(1:1.2). If the diameter of the wire is

0.4 mm or more, a wire having the mechanical strength required for sandblasting can be obtained. if in

If the thickness is 2.0 mm or less, even when sandblasting is performed on 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 of the wire after being cut into segments falls within this range, it is possible to perform sandblasting with less variation in finishing quality.

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

In one embodiment, the zinc-based alloy beads contain aluminum. Aluminum and zinc have a synergistic effect, so that the Vickers hardness and impact resistance (toughness) of zinc-based alloys are improved. If the content of aluminum is too small, the effect of addition will not be obtained, and if the content of aluminum is too large, the impact resistance of the zinc-based alloy tends to decrease because the influence of the physical properties of aluminum is too strong. In one embodiment, the content of aluminum (based on 100% of the total weight, the same below) is 0.05 to 0.20%, 0.06 to 0.19%, 0.09 to 0.14%, or 0.10 to 0.13% .

In one embodiment, the zinc-based alloy beads further contain magnesium. The addition of magnesium promotes recrystallization when stressed. That is, the hardness of the zinc-based alloy beads can be adjusted by applying stress in the manufacturing process, so that the zinc-based alloy beads having the blasting removal ability suitable for the purpose of blasting can be obtained. However, once too much magnesium is added, the impact resistance of the zinc-based alloy beads will be reduced, or there will be problems in manufacturing, so the content of magnesium is 0.001 to 0.20%, or 0.001 to 0.120% or 0.002% to 0.010%.

Copper is an element added to improve the corrosion resistance of zinc-based alloy beads. The improved corrosion resistance makes it possible to suppress the blackening of the workpiece surface when using this zinc-based alloy bead for sandblasting. However, once too much copper is added, the impact resistance of the zinc-based alloy beads will be reduced, so the addition amount is preferably a small amount. In one embodiment, the addition amount of copper (based on 100% of the total amount, the same applies hereinafter) is in the range of 0 to 0.05%, and may be in the range of 0.0001 to 0.01%, or in the range of 0.0002 to 0.01%, or in the range of 0.0002 to 0.005. %.

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 produce the aforementioned effect of suppressing the blackening of the workpiece, but also improve the blasting removal ability and life of the zinc-based alloy beads.

Zinc-based alloy beads are also used for low-hardness workpieces such as die-casting products composed of aluminum alloys, magnesium alloys, or zinc alloys. If the hardness of the zinc-based alloy beads is too low, the blasting removal ability of the workpiece will be insufficient, and if the hardness is too high, the design of the surface of the workpiece will be affected. Taking into account the physical properties of the workpiece and the purpose of blast grinding, the Vickers hardness of the zinc-based alloy beads is 80 to 150HV, or 80 to 100HV. The content of aluminum or the amount of copper added can be adjusted so that the hardness is within the above-mentioned range.

The zinc-based alloy beads of one embodiment are composed of zinc and aluminum and magnesium, or zinc and aluminum and magnesium and a trace amount of copper, but may also contain other unavoidable impurities. However, when the content of unavoidable impurities is high, the impact resistance is lowered, resulting in a reduction in life. Therefore, the total 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 0.06 to 0.19%, the content of magnesium relative to the zinc-based alloy beads is 0.001 to 0.120%, and the content of copper relative to the zinc-based alloy beads is 0.001 to 0.120%. The content of zinc-based alloy beads is 0.0001 to 0.01%, and the Vickers hardness of the zinc-based alloy beads is preferably 80 to 100HV.

Moreover, especially the content of aluminum relative to the zinc-based alloy beads is 0.09 to 0.14% or 0.10 to 0.13%, the content of magnesium relative to the zinc-based alloy beads is 0.002 to 0.010%, and the content of copper relative to the zinc-based alloy beads is 0.002 to 0.010%. The content of the zinc-based alloy beads is 0.0002 to 0.005%, and the Vickers hardness of the zinc-based alloy beads is preferably 80 to 100HV.

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

S01: Procedure for weighing the weight of raw materials

Scales the weight of the metal used as the raw material. For example, as the raw material (base metal) of aluminum, there can be mentioned: 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), First-class (99.990% or more), second-class (99.95% or more), as the raw material (base metal) of copper, examples include: JISH2121 electrolytic copper base metal (99.96% or more).

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

S02: Melting program

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

S03: Molten Metal Movement Procedure

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

A nozzle (nozzle) for dropping 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 nozzle. The cooling medium is liquid, such as water or oil.

S04: Granulation procedure

The molten metal that holds the molten metal in the container will drip from the pouring nozzle. During the period from the pouring nozzle to the arrival of 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 solidified directly in a spherical state.

The cooling medium heats up when it comes into contact with the molten metal, which prevents rapid cooling of the molten metal. Therefore, the cooling medium is kept at the set temperature by the cooling means. For example, when the cooling medium is water, the set cooling temperature can usually be set below 60°C, and can also be set within the range of 30 to 40°C.

S05: Grading Procedure

Granules of zinc-based alloys will accumulate at the bottom of the cooling medium. This granular body was collected and dried with a dryer, and then classified with a classifier to obtain spherical particles of the zinc-based alloy. The classification system is performed so as to have a predetermined particle size in accordance with the purpose of use of the zinc-based alloy beads.

Here, when the molten metal is dropped from the nozzle, the shape of the drop of the molten metal is not a perfect spherical shape, but a spherical shape or even an ellipse that is stretched and skewed in the falling direction. Therefore, the shape of the obtained granular body, that is, the particle|grains of a bead is a slightly skewed spherical shape, a spheroid shape, or a cylindrical shape with rounded corners. When the length in the longitudinal direction of the beads obtained from such a projection of the beads is a, and the maximum diameter in the direction perpendicular to the longitudinal direction is b, the a/b of 60% or more of the beads is preferably 1.0 to In the range of 1.3, preferably in the range of 1.0 to 1.2. Such beads are close to real balls, 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 a/b of the zinc-based alloy beads obtained by the hardness adjustment procedure S06 described later is 1.0 to 1.3 or 1.0 to 1.2. Therefore, it is possible to carry out classification to make the particle size within this range.

S06: Hardness Adjustment Procedure

Using a sandblasting machine, the classified spherical particles are repeatedly sprayed to the target (such as high manganese steel) for a predetermined number of times or Predetermined time (for example, 1 to 200 hours). The spherical particles impact the target violently, which will plastically deform and make the dislocation density (dislocation density) higher, so the hardness will become hard. The hardness of the spherical particles varies with the number of injections or injections. The amount of time varies, so by controlling these conditions, zinc-based alloy beads with predetermined hardness can be obtained. As long as those skilled in the art, can obtain zinc-based alloy beads with desired hardness by appropriately adjusting the above conditions .

Therefore, in the zinc-based alloy beads, the content of aluminum relative to the zinc-based alloy beads is 0.06 to 0.19%, the content of magnesium relative to the zinc-based alloy beads is 0.001 to 0.120%, and the content of copper relative to the zinc-based alloy beads is 0.001 to 0.120%. The content of zinc-based alloy beads is 0.0001 to 0.01 mass %, the zinc-based alloy beads are granular bodies with a diameter of 0.2 to 2.0 mm, and the length in the longitudinal direction of the beads obtained from the projection diagram is a, in the direction orthogonal to the longitudinal direction. In the case where the maximum diameter is b, more than 60% of the beads have a/b in the range of 1.0 to 1.3, and the Vickers hardness of the zinc-based alloy beads is preferably 80 to 100HV.

Moreover, especially the content of aluminum relative to the zinc-based alloy beads is 0.09 to 0.14% or 0.10 to 0.13%, and the content of magnesium relative to the zinc-based alloy beads is 0.001 to 0.120%, relative to the content of copper in the zinc-based alloy beads. The content is 0.0002 to 0.005%, the zinc-based alloy beads are granular bodies with a diameter of 0.2 to 2.0 mm, the length in the longitudinal direction of the beads obtained from the projection map is a, and the maximum in the direction orthogonal to the longitudinal direction is a. When the diameter is b, more than 60% of the beads have a/b in the range of 1.0 to 1.2, and the Vickers hardness of the zinc-based alloy beads is preferably 80 to 100 HV.

The manufacturing method of zinc-based alloy beads is not limited to the above-mentioned method. An example of the manufacturing method of another form is demonstrated below with reference to FIG. 2. FIG.

S11: Block Manufacturing Procedure

Blocks with a zinc-aluminum-magnesium or zinc-aluminum-magnesium-copper composition are produced from the metal as raw material. For example, smelting can be used to produce cylindrically-shaped lumps called billets from metals as raw materials.

S12: Wire Manufacturing Procedure

In this embodiment, a wire is produced from a compact. The briquettes are inserted into a plurality of dies, and the briquettes are drawn to reduce the diameter of the briquettes to a desired wire diameter due to plastic deformation, thereby producing wires. Since the compact of the present embodiment contains aluminum, the sliding property with the mold is very good. Therefore, it is possible to prevent the occurrence of wire breakage or generation of microcracks in the middle of the production of the wire.

In addition, the addition of copper as a trace addition element increases the tensile strength of the zinc-based alloy. In this way, it is possible to further prevent the occurrence of wire breakage or generation of microcracks in the middle of the production of the wire.

The addition of aluminum and copper allows the compact made of the zinc-based alloy to pass well through the mold, so the zinc-based alloy can be stressed due to plastic deformation and friction with the mold. As a result, mechanical properties (eg, toughness) required for beads can be improved. In addition, since magnesium is contained in the zinc-based alloy, the Vickers hardness can be increased by the application of the stress. For example, the mechanical properties and Vickers hardness can be adjusted by changing the drawing speed of the compact or the diameter and number of the molds.

0.4至2.0mm之範圍內。 The method of reducing the wire diameter of the wire increases the mechanical properties by applying stress to the zinc-based alloy, but if it is made thinner than necessary, it will be damaged by the processing. In addition, if the wire diameter is too large, the surface of the workpiece may be damaged when sandblasting is performed on a workpiece with insufficient stress or with a low hardness. Based on the above arguments, the diameter of the wire can be

Within the range of 0.4 to 2.0mm.

S13: Cut off procedure

The obtained thread was cut|disconnected to predetermined length in series along the longitudinal direction, and the granular material was obtained. When the difference between the length and the diameter of the granular material is large, the finishing quality of the workpiece after sandblasting will be uneven. Considering this point, the wire can be cut into segments in a way that satisfies (1:0.8)≦(diameter of wire: length of wire)≦(1:1.3), or it can be used to satisfy (1:0.8)≦(diameter of wire: The length of the wire)≦(1:1.2) The wire is cut off.

S14: Rounding program

The obtained granules have a cylindrical shape and therefore have corners. This corner will damage the workpiece during sandblasting, so it can be rounded by spraying the granular material 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 0.06 to 0.19%, the content of magnesium relative to the zinc-based alloy beads is 0.001 to 0.120%, and the content of copper relative to the zinc-based alloy beads is 0.001 to 0.120%. The content of Zn-based alloy beads is 0.0001 to 0.01 mass %, the zinc-based alloy beads are cylinders having a ratio of (1:0.83)≦(diameter:length)≦(1:1.25), and the length in the longitudinal direction of the beads is obtained from the projection diagram. It is a. In the case where the maximum diameter in the direction orthogonal to the length direction is b, the a/b of more than 60% of the beads is in the range of 1.0 to 1.3, and the Vickers hardness of the zinc-based alloy beads is in the range of 80 to 100HV. Zinc-based alloy beads are preferred.

Moreover, especially the content of aluminum relative to the zinc-based alloy beads is 0.09 to 0.14% or 0.10 to 0.13%, and the content of magnesium relative to the zinc-based alloy beads is 0.001 to 0.120%, relative to the content of copper in the zinc-based alloy beads. The content is 0.0002 to 0.005%, the zinc-based alloy bead is a cylinder having a ratio of (1:0.83)≦(diameter:length)≦(1:1.25), and the length in the longitudinal direction of the bead obtained from the projection diagram is a , In the case where the maximum diameter in the direction perpendicular to the length direction is b, the a/b of more than 60% of the beads is in the range of 1.0 to 1.2, and the Vickers hardness of the zinc-based alloy beads is 80 to 100HV. Alloy beads are better.

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

[Example]

From aluminum, magnesium and copper, and a zinc base metal weighed in the ratios shown in Table 1 to be described later, a zinc base alloy was produced by the aforementioned procedures S01 to S06 (type A) or procedures S11 to S14 (type B) beads.

Type A: manufactured by the procedures S01 to S06 of the above-mentioned manufacturing method, and classified into zinc-based alloy beads having an average particle size of 0.8 mm and the aforementioned a/b of 1.0 to 1.3.

Type B: Zinc-based alloy beads manufactured with 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 blasting machine (DZB type: manufactured by Shinto Kogyo Co., Ltd.), and an aluminum alloy die-casting part (surface hardness: 100 HV) as a workpiece was blasted to evaluate performance. The spray velocity of the zinc-based alloy beads was 53 m/s.

The evaluation items included "consumption amount", "burr removal ability", and "dressing quality", and were carried out as follows.

<consumption>

This corresponds to the evaluation of life and toughness (impact resistance). The amount of the zinc-based alloy beads that was used for sandblasting for 8 hours and thus became fine powder and was lost was used as the "bead consumption amount", and was evaluated on the basis of the following criteria.

◎: Below 0.06kg/(h‧HP)

○: 0.06kg/(h‧HP) to 0.08kg/(h‧HP)

△: 0.08kg/(h‧HP) to 0.10kg/(h‧HP)

×: 0.10kg/(h‧HP) or more

<Burr removal ability>

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

◎: The burrs are removed with a blasting time of 30 seconds

○: The burrs are removed with a blasting time of 60 seconds

△: The burrs are removed with a blasting time of 90 seconds

×: The burrs were not removed even with a blasting time of 90 seconds

<Trimming quality>

The workpiece surface after sandblasting was observed, and the following criteria were used for evaluation (evaluation by visual observation).

◎: Emits silvery white luster

○: Slightly darkened

△: Blackened

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" of the wire after being cut in the B-type zinc-based alloy bead.

The composition of Example 8 and Example 7 are the same, but the injection time in the aforementioned hardness adjustment procedure S06 is changed to obtain different hardness results. It can be seen that the hardness of the zinc-based alloy beads of type A can be adjusted by the hardness adjustment program S06.

<Evaluation of consumption>

Both types of zinc-based alloy beads are the same, and Examples 1 to 16 in which the addition amount of aluminum is in the range of 0.05 to 2.0% and the addition amount of magnesium is in the range of 0.01 to 0.20% have an evaluation above △ regardless of the conditions. . In addition, even in the case where copper in the range of 0.0002 to 0.01% was added in a small amount, the evaluation was equal to or higher than △ regardless of the conditions. Here, although the Δ evaluation is inferior to the ○ evaluation, there is no practical problem, and it means that an evaluation of ○ or more can be obtained by optimizing the ejection conditions (ejection speed, particle size, etc.). From this, it can be seen that in Examples 1 to 16, the evaluation of the consumption is good.

Comparative Example 3 in which the addition amount of aluminum was too large, Comparative Example 5 in which the addition amount of magnesium was too large, and Comparative Example 6 in which the addition amount of copper was too large were all evaluated as ×. In the case of the three, it is presumed that the impact resistance deteriorated due to excessive addition of aluminum, magnesium, and copper.

<Burr removal ability>

Both types of zinc-based alloy beads are the same, with the addition of aluminum in the range of 0.05 to 2.0% and the addition of magnesium in the range of 0.001 to 0.20% in Examples 1 to 16, it can be seen that the addition of aluminum and magnesium is increased. If so, the evaluation tends to decrease, but there is an evaluation above △ regardless of the conditions. In addition, even in the case where copper in the range of 0.0002 to 0.01% was added in a small amount, the evaluation was equal to or higher than △ regardless of the conditions. Here, although the Δ evaluation is inferior to the ○ evaluation, there is no practical problem, and it means that an evaluation of ○ or more can be obtained by optimizing the ejection conditions (ejection speed, particle size, etc.). From this, it can be seen that in Examples 1 to 16, the evaluation of the burr removal ability was favorable.

The comparative example 1 in which aluminum was not added and the comparative example 2 in which the addition amount was too small were evaluated as ×. This is presumably because the Vickers hardness is lower than that of the workpiece.

Comparative Example 4 in which magnesium was not added was evaluated as x. This is presumably because the hardness-enhancing effect of the zinc-based alloy beads in the manufacturing process is insufficient and the Vickers hardness is lower than that of the workpiece.

In Comparative Examples 7 and 8 in which the diameter-length ratio was too small or too large, the evaluation was x. The reason for this can be assumed that the impact of the zinc-based alloy beads on the workpiece is uneven, which reduces the burr removal ability.

<Trimming quality>

Both types of zinc-based alloy beads are the same, in Examples 5 to 8 and 13 to 16, in which copper in the range of 0.0002 to 0.01% was added in a small amount, regardless of the conditions, there was an evaluation of ◎, indicating that a small amount was added Copper will improve the quality of the trim.

In addition, in Examples 1 to 4 and 9 to 12 to which no copper was added, the evaluations were Δ or ∘, and the results of Comparative Example 1 were viewed together, and it was found that the improvement of the trimming quality was also observed with the addition of aluminum. This is presumably because the increased burr removal capability reduces the time until blasting is completed, thereby reducing the exposure of the workpiece to the jet of zinc-based alloy beads.

(industrial availability)

The zinc-based alloy beads of one embodiment are suitable for the removal of burrs and burrs of non-ferrous metal parts such as aluminum die-casting products and aluminum casting products, sand cleaning of castings, and mold coating or mold release agents for burning and sticking. Sand blasting for the purpose of removal, removal of oxide film or flow marks, and hole sealing.

S01 to S06‧‧‧Programs

Claims (8)

A zinc-based alloy bead, which is composed of aluminum and magnesium and the remaining part of zinc and inevitable impurities, wherein the content of aluminum relative to the aforementioned zinc-based alloy bead is 0.05 to 0.20 mass % and the content of magnesium is 0.001 to 0.20 mass %, and the Vickers hardness of the aforementioned zinc-based alloy beads is 80 to 150 HV. The zinc-based alloy beads according to claim 1, wherein the zinc-based alloy beads are further added with copper as a trace addition element, and relative to the zinc-based alloy beads, the addition amount of the trace addition elements accounts for 0.0002 to 0.01 mass %. The zinc-based alloy beads according to claim 1 or 2, wherein the zinc-based alloy beads are granular bodies having a diameter of 0.2 to 2.0 mm, or are (1:0.8)≦(diameter: length)≦(1:1.3), and the Vickers hardness of the zinc-based alloy beads is 80 to 150 HV. The zinc-based alloy bead according to claim 1 or 2, wherein the zinc-based alloy bead is a granular body, and the length in the longitudinal direction of the bead obtained from the projection diagram is a, and the length When the maximum diameter in the direction orthogonal to the direction is b, the a/b of more than 60% of the beads is in the range of 1.0 to 1.3. A manufacturing method of zinc-based alloy beads, which is the manufacturing method of zinc-based alloy beads described in any one of items 1 to 4 of the patent application scope, comprising: weighing zinc, aluminum, magnesium as raw materials, and as needed And the procedure of adding the weight of copper; The process of heating the raw metal to become molten metal; the process of transferring the molten metal to a molten metal holding container equipped with a pouring nozzle at the bottom; the process of dropping the molten metal into a liquid cooling medium through the pouring nozzle A procedure for solidifying the molten metal in the cooling medium to obtain granular bodies; a procedure for classifying the solidified granular bodies into a predetermined size; and a procedure for adjusting the hardness of the granular bodies after the classification, wherein , the aforementioned classification procedure is performed to classify the diameter of the aforementioned solidified molten metal into 0.2 to 2.0 mm. 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 items 1 to 3 of the scope of the patent application, comprising: obtaining zinc, aluminum, magnesium, The process of adding a copper alloy to form a block; the process of obtaining a wire of a predetermined wire diameter from the block; and the process of cutting the wire into a predetermined length, wherein the process of obtaining the wire includes cutting The procedure in which the block is rolled and stressed. The method for producing zinc-based alloy beads according to claim 6, wherein the process of cutting the wire is to cut the wire into (1:0.8)≦(diameter of wire:length of wire)≦( 1:1.3). The method for producing zinc-based alloy beads according to claim 6 or 7, wherein the procedure for obtaining the wire is to process the block into a wire with a diameter of

0.4 to 2.0mm.

Images