JP6965926B2 - Zinc-based alloy shot and its manufacturing method - Google Patents

Description

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

Blasting, in which particles called shots collide with a work piece to perform surface treatment (deburring, rounding (Ring), surface roughness adjustment, satin finish, etc.) of the work, has been known for a long time. The material of the shot is selected according to the material of the work and the processing purpose. For example, in the case of blasting a die-cast product composed of an aluminum alloy, a magnesium alloy, or a zinc alloy, zinc shot is selected in consideration of cleaning ability and dust explosive resistance.

Patent Document 1 discloses a shot made of zinc. Since this shot has a Vickers hardness of 40 to 50 HV (specified by JIS Z2244), its cleaning ability is low.

Therefore, shots made of zinc alloy have been developed. For example, Patent Document 2 discloses a zinc-based alloy shot composed of Zn—Mn. However, Mn is subject to the PRTR system and is not preferable from the viewpoint of safety and environmental protection.

Japanese Unexamined Patent Publication No. 63-312067 Japanese Unexamined Patent Publication No. 2001-162538

In view of the above, it is an object of the present invention to provide a new zinc-based alloy shot having a high cleaning ability and a long life, and a method for producing the same.

INDUSTRIAL APPLICABILITY The present invention provides the following zinc-based alloy shots and a method for producing the same.
[1] A zinc-based alloy shot.
The zinc-based alloy shot consists of Al, the balance of Zn, and unavoidable impurities.
The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0% by mass.
A zinc-based alloy shot having a Vickers hardness of 50 to 100 HV.
[2] The zinc-based alloy shot according to the above item 1, wherein the zinc-based alloy shot has a Vickers hardness of 50 to 90 HV.
[3] In the previous zinc-based alloy shot, Cu is further added as a trace additive element, and Cu is added.
The zinc-based alloy shot according to item 1 or 2, wherein the amount of the trace-added element added is 0.0001 to 0.25% by mass with respect to the zinc-based alloy shot.
[4] The zinc-based alloy shot is a granular material having a diameter of 0.2 to 2.0 mm, or (1: 0.8) ≤ (diameter: length) ≤ (1: 1.3). The zinc-based alloy shot according to any one of 1 to 3 above, which is a cylinder having the ratio of.
[5] The zinc-based alloy shot is a granular material, and is 60% or more when the length of the shot obtained from the projection drawing in the longitudinal direction is a and the maximum diameter in the direction orthogonal to the longitudinal direction is b. The zinc-based alloy shot according to the above 1 to 4, wherein the a / b of the shot is in the range of 1.0 to 1.3.
[6] The method for producing a zinc-based alloy shot according to any one of 1 to 5 above.
The process of weighing the raw metal Zn, Al, and Cu as needed,
The process of heating the raw material metal to form a molten metal, and
A step of transferring the molten metal to a molten metal holding container having a nozzle arranged at the bottom, and
The step of dropping the molten metal into the liquid cooling medium through the nozzle, and
A step of coagulating the molten metal in the cooling medium to obtain granules,
A step of classifying the granules into a predetermined size and
Including
The method for producing a zinc-based alloy shot, in which the diameter of the solidified molten metal is classified into 0.2 to 2.0 mm in the classification step.
[7] The method for producing a zinc-based alloy shot according to any one of 1 to 4 above.
A step of obtaining a mass having an alloy composition of Zn, Al, which are raw materials, and Cu, if necessary, and
A step of obtaining a wire having a predetermined diameter from the lump, and
The step of cutting the wire to a predetermined length and
Including
The method for producing a zinc-based alloy shot, which comprises a step of rolling a lump and applying stress in the step of obtaining the wire.
[8] In the step of cutting the wire, the wire is cut so that (1: 0.8) ≤ (diameter of the wire: length of the wire) ≤ (1: 1.3). The method for producing a zinc-based alloy shot according to the description.
[9] The method for producing a zinc-based alloy shot according to item 7 or 8, wherein in the step of obtaining the wire, a lump is processed so that the diameter of the wire is φ0.4 to 2.0 mm.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a zinc-based alloy shot having a high cleaning ability and a long life. By including a predetermined amount of Cu, it is possible to provide a zinc-based alloy shot in which not only the occurrence of darkening of the work is suppressed but also the cleaning ability, the life and the tensile strength are improved.

It is a flowchart for demonstrating one Embodiment of the manufacturing method of the zinc-based alloy shot of this invention. It is a flowchart for demonstrating another embodiment of the manufacturing method of the zinc-based alloy shot of this invention.

One aspect of the present invention is a zinc-based alloy shot. The zinc-based alloy shot consists of Al, the balance of Zn, and unavoidable impurities. The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0% by mass. The Vickers hardness of the zinc-based alloy shot is 50 to 90 HV.

Since Al is added to the zinc-based alloy shot on one side of the present invention, the hardness is higher than that of zinc, and the cleaning ability is high. In addition, since the impact resistance (toughness) is improved, the life is long. Since Al is relatively inexpensive, zinc-based alloy shots having high cleaning ability and long life can be produced at low cost.

In one embodiment of the present invention, Cu may be further added as a trace element to the zinc-based alloy shot. Then, the amount of the trace addition element added may be 0.0002 to 0.25% by mass with respect to the zinc-based alloy shot. By adding a small amount of Cu, it is possible to suppress the occurrence of darkening when the blasting process is performed.

Another embodiment of the present invention is a zinc-based alloy shot.
The zinc-based alloy shot is composed of Al, Cu as a trace additive element, Zn as a balance, and unavoidable impurities.
The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0% by mass.
The Cu content with respect to the zinc-based alloy shot is 0 to 0.25% by mass.
The zinc-based alloy shot is a granular material having a diameter of 0.2 to 2.0 mm, or a ratio of (1: 0.8) ≤ (diameter: length) ≤ (1: 1.3). It is a cylinder that has
The zinc-based alloy shot has a Vickers hardness of 50 to 90 HV.

One embodiment of the present invention is a method for producing a zinc-based alloy shot. This production method may include the following steps (1) to (6).
(1) A step of weighing Zn, Al, which are raw material metals, and Cu, if necessary.
(2) A step of heating the raw material metal to form a molten metal.
(3) A step of transferring the molten metal to a molten metal holding container having a nozzle arranged at the bottom.
(4) A step of dropping the molten metal into a liquid cooling medium via a nozzle.
(5) A step of coagulating the molten metal in a cooling medium to obtain granules.
(6) A step of classifying granules into a predetermined size.
Then, in the step (6), the particles may be classified so that the diameter of the granules is 0.2 to 2.0 mm. In addition, in this specification, "diameter" means a diameter.

By containing Al, the fluidity of the molten metal is improved. Therefore, the nozzle can be satisfactorily dropped without being blocked by the molten metal. Further, when the diameter of the granules is 0.2 to 2.0 mm, granules having a relatively uniform shape can be obtained.

One embodiment of the present invention is a method for producing a zinc-based alloy shot. This production method may include the following steps (11) to (13).
(11) A step of obtaining a mass having an alloy composition of Zn, Al, which are raw materials, and Cu, if necessary.
(12) A step of obtaining a wire having a predetermined diameter from a lump material.
(13) A step of cutting a wire to a predetermined length.
Then, the step of obtaining the wire may include a step of rolling the lump and applying stress.

By containing Al, the toughness of the alloy is improved. As a result, when the lump is rolled and processed into a wire shape, it is not broken during the processing. Further, by applying stress to the wire when rolling the lump, the mechanical properties are improved.

In one embodiment of the present invention, in the step of obtaining the wire, a lump is processed so that the diameter of the wire is φ0.4 to 2.0 mm, and in the step of cutting the wire, (1: 0.8) ≦ (Wire diameter: wire length) ≤ (1: 1.3) or (1: 0.8) ≤ (wire diameter: wire length) ≤ (1: 1.2) ) May be cut. When the diameter of the wire is φ0.4 mm or more, a wire having the mechanical strength required for blasting can be obtained. Further, if the diameter is 2.0 mm or less, the work will not be damaged more than necessary even when a relatively soft work such as an aluminum die-cast product is blasted. Then, by cutting the wire so that the ratio of the diameter and the length of the wire after cutting is within this range, blasting with little variation in the finished quality can be performed.

An embodiment of the zinc-based alloy shot of the present invention and a method for producing the same will be described with reference to the drawings. The present invention is not limited to one embodiment, and can be appropriately modified within an equal range. Further, in the following description, "%" indicating the alloy composition indicates "mass%" unless otherwise specified.

Al is contained in the zinc-based alloy shot of one embodiment. Al has improved Vickers hardness and impact resistance (toughness) of the zinc-based alloy due to the synergistic effect with Zn. If the Al content is too low, the added effect cannot be obtained. If it is too large, the influence of the physical properties of Al becomes too strong, and the impact resistance of the zinc-based alloy tends to decrease. In one embodiment, the Al content (100% total amount standard: the same applies hereinafter) is 1.0 to 6.0%, may be 1.3 to 5.8%, or 2.9 to 5. It may be 6%.

Cu is an element added as needed to improve the corrosion resistance of zinc-based alloy shots. As a result of the improved corrosion resistance, it is possible to suppress the occurrence of darkening on the surface of the work when blasting using this zinc-based alloy shot. However, if Cu is added in excess, the impact resistance of the zinc-based alloy shot is lowered, so the amount added is preferably a small amount. In one embodiment, the amount of Cu added (100% total amount standard: the same applies hereinafter) is 0 to 0.25%, may be 0.0001 to 0.25%, or 0.0002 to 0.25. It may be 0.0002 to 0.05%.

Cu also has the effect of improving the Vickers hardness and impact resistance of zinc-based alloy shots. Adding a small amount of Cu not only imparts the effect of suppressing the occurrence of darkening to the work described above, but also has the effect of further improving the cleaning ability and life of the zinc-based alloy shot.

Zinc-based alloy shots are also used for workpieces with relatively low hardness, such as die-cast products made of aluminum alloys, magnesium alloys, and zinc alloys. If the hardness of the zinc-based alloy shot is too low, the cleaning ability for the work will be insufficient, and if it is too hard, the design of the surface of the work will be affected. Considering the physical characteristics of the work and the purpose of cleaning, the Vickers hardness of the zinc-based alloy shot may be 50 to 100 HV, 50 to 90 HV, or 70 to 90 HV. The content of Cu or the amount of Cu added may be adjusted.

The zinc-based alloy shot of one embodiment is composed of Zn and Al, or Zn and Al and a trace amount of Cu, but may contain other unavoidable impurities. However, if the content of unavoidable impurities is high, the impact resistance is lowered, which leads to a decrease in life. Therefore, it is desirable that the total content of unavoidable impurities is as small as possible.

The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0%.
The Cu content with respect to the zinc-based alloy shot is 0.0001 to 0.25% by mass.
A zinc-based alloy shot having a Vickers hardness of 50 to 100 HV is particularly preferable.

The Al content with respect to the zinc-based alloy shot is 1.3 to 5.8%.
The Cu content with respect to the zinc-based alloy shot is 0.0002 to 0.05% by mass.
A zinc-based alloy shot having a Vickers hardness of 70 to 90 HV is even more preferable.

Next, a method for producing a zinc-based alloy shot of one embodiment will be described below with reference to FIG.

S01: Step of weighing the raw material Weigh the metal as the raw material. For example, as the raw material (bullyion) of Al, JISH2102 aluminum bullion special type 1 (99.90% or more) and JISH2111 (or ICS77.120.10) refined aluminum bullion special (99.995% or more) -Type 1 (99.990% or more) -Type 2 (99.95% or more), and as the raw material (bare metal) for Cu, JISH2121 electrolytic copper bullion (99.96% or more), respectively. Can be done.

The raw material (bare metal) for Zn, which is the basic element, is not particularly limited, and each grade specified in JIS H2107 (or ISO725: 1981) can be used. Considering the quality stability of shots, JIS H2107 ordinary zinc bullion (99.97% or more), pure zinc bullion (99.995% or more), special zinc bullion (99.99% or more), etc. High-purity zinc bullion may be used.

S02: Melting step 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 form a molten metal having a composition of Zn-Al or Zn-Al-Cu.

S03: Molten metal transfer step The molten metal is put into the molten metal holding container. The molten metal holding container is provided with a heating means, and can hold the molten metal so that it is not cooled more than necessary during the production of zinc-based alloy shots. The molten metal holding temperature at this time varies depending on the alloy composition and the production scale, but may be appropriately set in the range of 500 to 600 ° C.

A nozzle for dropping molten metal is provided at the bottom of the molten metal holding container, and a cooling tank into which a cooling medium is charged is arranged below the nozzle. The cooling medium is a liquid and may be water, oil, or the like.

S04: Granulation step The molten metal in the molten metal holding container is dropped from the nozzle. Before reaching the cooling medium from the nozzle, it becomes spheroidized under the influence of surface tension. The molten metal that reaches the cooling medium and comes into contact with it is rapidly cooled and solidified in a spherical shape.

The temperature of the cooling medium rises due to contact with the dropped molten metal, which causes the rapid cooling of the molten metal to be hindered. Therefore, the cooling means keeps the cooling medium at the set temperature. In the case of water, for example, the set cooling temperature may be usually 60 ° C. or lower, or 30 to 40 ° C.

S05: Classification step Zinc alloy granules are deposited on the bottom of the cooling medium. This is collected, dried in a dryer, and then classified in a classifier to obtain a zinc-based alloy shot. The classification is performed so that the particle size becomes a predetermined size according to the purpose of use of the zinc-based alloy shot.

Here, when the molten metal is dropped from the nozzle, the shape of the droplet of the molten metal is not a perfect sphere, but a sphere or an ellipse that is stretched and distorted in the falling direction. Therefore, the shape of the obtained granules, that is, the particles of the shot, is a slightly distorted spherical shape, a spheroidal shape, or a columnar shape with rounded corners. When the length of the shot in the longitudinal direction obtained from the projection drawing of such a shot is a and the maximum diameter in the direction orthogonal to the longitudinal direction is b, the a / b of a shot of 60% or more is 1.0 to 1.0 to It is preferably in the range of 1.3, and is also preferably in the range of 1.0 to 1.2. Since such a shot is close to a true sphere and has a small variation in shape, a more uniform cleaning effect can be obtained. When the diameter of the granules is 0.2 to 2.0 mm, the proportion of shots with a / b values of 1.0 to 1.3 or 1.0 to 1.2 increases, so the particle size falls within this range. The classification may be performed so as to become.

The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0%.
The Cu content with respect to the zinc-based alloy shot is 0.0001 to 0.25% by mass.
The zinc-based alloy shot is a granular material having a diameter of 0.2 to 2.0 mm.
When the length of the shot obtained from the projection drawing in the longitudinal direction is a and the maximum diameter in the direction orthogonal to the longitudinal direction is b, the a / b of 60% or more shots is in the range of 1.0 to 1.3. Inside,
A zinc-based alloy shot having a Vickers hardness of 50 to 100 HV is particularly preferable.

The Al content with respect to the zinc-based alloy shot is 1.3 to 5.8% by mass.
The Cu content with respect to the zinc-based alloy shot is 0.0002 to 0.05%.
The zinc-based alloy shot is a granular material having a diameter of 0.2 to 2.0 mm.
When the length of the shot obtained from the projection drawing in the longitudinal direction is a and the maximum diameter in the direction orthogonal to the longitudinal direction is b, the a / b of 60% or more shots is in the range of 1.0 to 1.2. Inside,
A zinc-based alloy shot having a Vickers hardness of 70 to 90 HV is even more preferred.

The method for producing a zinc-based alloy shot is not limited to the above method. An example of another form of manufacturing method will be described below with reference to FIG.

S11: Mass production process A mass having a composition of Zn—Al or Zn—Al—Cu is produced from a metal as a raw material. For example, a cylindrical mass called a billet may be produced from a metal as a raw material by smelting.

S12: Wire manufacturing process In this embodiment, a wire is manufactured from a billet. By inserting billets into a plurality of dies and pulling out the billets, the diameter of the billets is reduced by plastic deformation to manufacture a wire to a desired diameter. Since the billet of this embodiment contains Al, it has good slipperiness with the die. Therefore, when the wire is manufactured, it is possible to prevent the wire from being cut or microcracking during the process.

Further, since Cu is added as a trace additive element, the tensile strength of the zinc-based alloy is improved. As a result, it is possible to prevent the wire from being cut or microcracked during the wire production.

Since the billet made of the zinc-based alloy can pass through the die well by adding Al and Cu, the zinc-based alloy can be stressed by plastic deformation and friction with the die. As a result, the mechanical properties (for example, toughness) required for the shot can be improved. For example, the mechanical properties can be adjusted by changing the pulling speed of the billet and the diameter and number of dice.

By reducing the diameter of the wire, stress is applied to the zinc-based alloy and the mechanical properties are improved, but if it is made thinner than necessary, it will be damaged by this processing. Further, if the diameter is too large, sufficient stress is not applied, or when blasting is performed on a work having a relatively low hardness, the surface of the work is damaged. Based on the above, the diameter of the wire may be φ0.4 mm to 2.0 mm.

S13: Cutting step The obtained wires are cut in series so as to have a predetermined length to obtain granules. If the length of the granules has a large difference from the diameter, the finished quality of the work after blasting will vary. In consideration of this, the wire may be cut so that (1: 0.8) ≤ (wire diameter: wire length) ≤ (1: 1.3), and (1: 0.8). The wire may be cut so that ≦ (wire diameter: wire length) ≦ (1: 1.2).

S14: Rounding step Since the obtained granules have a cylindrical shape, they have corners. If the work is damaged by the corners during blasting, the corners may be rounded by projecting the granules toward a wall or the like in advance. This step may be omitted depending on the physical characteristics of the work and the purpose of the blasting process.

The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0%.
The Cu content with respect to the zinc-based alloy shot is 0.0001 to 0.25%.
The zinc-based alloy shot is a cylinder having a ratio of (1: 0.83) ≤ (diameter: length) ≤ (1: 1.25).
When the length of the shot obtained from the projection drawing in the longitudinal direction is a and the maximum diameter in the direction orthogonal to the longitudinal direction is b, the a / b of 60% or more shots is in the range of 1.0 to 1.3. Inside,
A zinc-based alloy shot having a Vickers hardness of 50 to 100 HV is particularly preferable.

The Al content with respect to the zinc-based alloy shot is 1.3 to 5.8%.
The Cu content with respect to the zinc-based alloy shot is 0.0002 to 0.25%.
The zinc-based alloy shot is a cylinder having a ratio of (1: 0.83) ≤ (diameter: length) ≤ (1: 1.25).
When the length of the shot obtained from the projection drawing in the longitudinal direction is a and the maximum diameter in the direction orthogonal to the longitudinal direction is b, the a / b of 60% or more shots is in the range of 1.0 to 1.2. Inside,
A zinc-based alloy shot having a Vickers hardness of 70 to 90 HV is particularly preferable.

Next, the result of evaluating the zinc-based alloy shot of one embodiment will be described.

A zinc-based alloy shot is made from Al and Cu weighed so as to have the ratio shown in Table 1 described later and Zn bullion by the above-mentioned steps S01 to S05 (A type) or steps S11 to S14 (B type). Manufactured.
A type: A zinc-based alloy produced by steps S01 to S05 in the above-mentioned production method and classified so that the average particle size is 0.8 mm and the above-mentioned a / b is 1.0 to 1.3.
B type: A zinc-based alloy shot produced by steps S11 to S14 and having a wire diameter of 0.8 mm.

The following evaluation tests were conducted on these zinc-based alloy shots.

100 kg of zinc-based alloy shots are put into a shot blasting machine (DZB type: manufactured by Shinto Kogyo Co., Ltd.), and aluminum alloy die-cast parts (surface hardness: 100 HV) are blasted as workpieces to evaluate their performance. I did. The projection speed of the zinc-based alloy shot was set to 53 m / s.

The evaluation items were as follows for "consumable amount", "deburring ability" and "finished quality".

<Consumable amount>
It is an evaluation corresponding to the life or toughness (impact resistance). The amount of fine powder that was worn by shot blasting for 8 hours using a zinc-based alloy shot was evaluated as the "shot consumption amount" according to the following criteria.
⊚: 0.06 kg / (h ・ HP) or less ○: 0.06 kg / (h ・ HP) to 0.08 kg / (h ・ HP)
Δ: 0.08 kg / (h ・ HP) to 0.10 kg / (h ・ HP)
X: 0.10 kg / (h · HP) or more

<Deburring ability>
It is an evaluation corresponding to the cleaning ability or blasting ability. The blasting time required for the burrs to be completely removed was measured and evaluated according to the following criteria. The removal of burrs was visually evaluated.
⊚: Burrs are removed in a blasting time of 30 seconds.
◯: Burrs are removed in a blasting time of 60 seconds.
Δ: Burrs are removed in a blasting time of 90 seconds.
X: Burrs are not removed even with a blasting time of 90 seconds.

<Finish quality>
The surface of the work after blasting was observed and evaluated according to the following criteria (visual evaluation).
⊚: Shining silvery white.
○: It is a little dark.
Δ: It is darkened.

The evaluation results are shown in Table 1. In the table, the "diameter-length ratio" indicates the "wire diameter: wire length" of the wire after cutting in the B-type zinc-based alloy shot.

<Evaluation of consumption>
In any type of zinc-based alloy shot, Examples 1 to 10 in which the amount of Al added was in the range of 1.0 to 6.0% were evaluated as Δ or higher under all conditions. Further, even when a small amount of Cu was added in the range of 0.0001 to 0.25%, the evaluation was Δ or higher under any condition. Here, the Δ evaluation is inferior to the ○ evaluation, but there is no problem in practical use, and it is suggested that the evaluation can be higher than the ○ evaluation by optimizing the projection conditions (projection speed, particle size, etc.). Therefore, in Examples 1 to 10, it can be seen that the evaluation of the amount of consumption is good.

In the B-type zinc-based alloy shot, when the composition was close to that of the type A zinc-based alloy shot, the evaluation of the amount of consumption was the same or even better. It is considered that this is because the process of applying stress in the manufacturing process of the B-type zinc-based alloy shot is included, so that the mechanical properties of the zinc-based alloy shot are improved, and as a result, the impact resistance is improved. ..

Comparative Example 3 in which the amount of Al added was excessive and Comparative Example 4 in which the amount of Cu added was excessive were evaluated as x. In either case, it is considered that the impact resistance deteriorated due to the excessive addition of Al and Cu.

<Deburring ability>
In any type of zinc-based alloy shot, in Examples 1 to 10 in which the amount of Al added is in the range of 1.0 to 6.0%, the evaluation tends to decrease as the amount of Al added increases. However, the evaluation was Δ or higher under all conditions. Further, even when a small amount of Cu was added in the range of 0.0001 to 0.25%, the evaluation was Δ or higher under any condition. Here, the Δ evaluation is inferior to the ○ evaluation, but there is no problem in practical use, and it is suggested that the evaluation can be higher than the ○ evaluation by optimizing the projection conditions (projection speed, particle size, etc.). Therefore, in Examples 1 to 10, it can be seen that the evaluation of the amount of consumption is good.

In the B-type zinc-based alloy shot, when the composition was close to that of the type A zinc-based alloy shot, the evaluation of the deburring ability was the same or even better. It is considered that this is because the mechanical properties of the zinc-based alloy shot are improved because the step of applying stress is included in the manufacturing process of the B-type zinc-based alloy shot.

Comparative Example 1 in which Al was not added and Comparative Example 2 in which the amount of Al added was too small were evaluated as x. This is considered to be due to the low Vickers hardness with respect to the work.

Comparative Examples 5 and 6 in which the diameter-length ratio was too small or too large were all evaluated as x. It is considered that the deburring ability was reduced as a result of the variation in the collision of the zinc-based alloy shot with the work.

<Finish quality>
In any type of zinc-based alloy shot, Examples 3, 4, 7, 8, 9, and 10 in which a small amount of Cu was added in the range of 0.0001 to 0.25% were evaluated as ◎ under any condition. It was shown that the finished quality is improved by adding a small amount of Cu.

Further, in Examples 1, 2, 5 and 6 to which Cu was not added, the evaluation was Δ or ◯, and when the results of Comparative Example 1 were taken into consideration, the addition of Al also improved the finished quality. It is considered that this is because the time until the blasting process is completed is shortened due to the improved deburring ability, so that the opportunity for the workpiece to be exposed to the projected flow of the zinc-based alloy shot is reduced.

The zinc-based alloy shot of one embodiment removes burrs and burrs of non-ferrous metal parts such as aluminum die-cast products and aluminum casting products, removes sand from castings, removes seizure of coating molds and mold release agents, and oxide films. It can be suitably used for shot blasting for the purpose of removing water wrinkles, sealing holes, and the like.

Claims (8)

It ’s a zinc-based alloy shot.
The zinc-based alloy shot consists of Al, the balance of Zn, and unavoidable impurities.
The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0% by mass.
Cu is further added as a trace element to the zinc-based alloy shot .
The amount of the trace addition element added is 0.0001 to 0.05% by mass with respect to the zinc-based alloy shot .
A zinc-based alloy shot having a Vickers hardness of 50 to 100 HV. The zinc-based alloy shot according to claim 1, wherein the zinc-based alloy shot has a Vickers hardness of 50 to 90 HV. The zinc-based alloy shot is a granular material having a diameter of 0.2 to 2.0 mm, or a ratio of (1: 0.8) ≤ (diameter: length) ≤ (1: 1.3). The zinc-based alloy shot according to claim 1 or 2 , which is a cylinder having. When the zinc-based alloy shot is a granular material and the length of the shot obtained from the projection drawing in the longitudinal direction is a and the maximum diameter in the direction orthogonal to the longitudinal direction is b, a of shots of 60% or more. The zinc-based alloy shot according to any one of claims 1 to 3 , wherein / b is in the range of 1.0 to 1.3. It is a manufacturing method of zinc-based alloy shots.
The process of weighing the raw metal Zn, Al, and Cu as needed,
The process of heating the raw material metal to form a molten metal, and
A step of transferring the molten metal to a molten metal holding container having a nozzle arranged at the bottom, and
The step of dropping the molten metal into the liquid cooling medium through the nozzle, and
A step of coagulating the molten metal in the cooling medium to obtain granules,
A step of classifying the granules into a predetermined size and
Including
The zinc-based alloy shot consists of Al, the balance of Zn, and unavoidable impurities .
The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0% by mass .
Cu is further added as a trace element to the zinc-based alloy shot .
The amount of the trace addition element added is 0.0001 to 0.05% by mass with respect to the zinc-based alloy shot .
The Vickers hardness of the zinc-based alloy shot is 50 to 100 HV .
The method for producing a zinc-based alloy shot, in which the diameter of the solidified molten metal is classified into 0.2 to 2.0 mm in the classification step. It is a manufacturing method of zinc-based alloy shots.
A step of obtaining a mass having an alloy composition of Zn, Al, which are raw materials, and Cu, if necessary, and
A step of obtaining a wire having a predetermined diameter from the lump, and
The step of cutting the wire to a predetermined length and
Including
The zinc-based alloy shot consists of Al, the balance of Zn, and unavoidable impurities .
The Al content with respect to the zinc-based alloy shot is 1.0 to 6.0% by mass .
Cu is further added as a trace element to the zinc-based alloy shot .
The amount of the trace addition element added is 0.0001 to 0.05% by mass with respect to the zinc-based alloy shot .
The Vickers hardness of the zinc-based alloy shot is 50 to 100 HV .
The method for producing a zinc-based alloy shot, which comprises a step of rolling a lump and applying stress in the step of obtaining the wire. The zinc according to claim 6 , wherein in the step of cutting the wire, the wire is cut so that (1: 0.8) ≤ (wire diameter: wire length) ≤ (1: 1.3). How to make a base alloy shot. The method for producing a zinc-based alloy shot according to claim 6 or 7 , wherein in the step of obtaining the wire, a lump is processed so that the diameter of the wire is φ0.4 to 2.0 mm.

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