JP2012020306A - Mg ALLOY-COILED MATERIAL AND METHOD FOR PRODUCTION THEREOF - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Mg alloy-coiled material having substantially smooth surface over the whole length of a coiled material and excellent in surface property, and to provide a method for production thereof.SOLUTION: The invention relates to a Mg alloy-coiled material comprising winding up a long rolled material consisting of a Mg alloy. The difference between the surface roughness Rz in the longitudinal direction of the rolled material and that in the lateral direction is ≤5 μm. The Mg alloy coiled material is produced by a method comprising the steps of: sandwiching the long raw material comprising the Mg alloy between the long metal materials except the Mg alloy; rolling the raw material sandwiched by the metal materials together with them; and peeling the metal materials from the rolled raw material after rolling. According to the production method, since a polishing process can be eliminated, the occurrence of polishing trace resulting from the polishing process can be prevented, and thus the Mg alloy coiled material having substantially smooth surface over the whole length of the coiled material and excellent in surface property can be efficiently obtained.

Description

  The present invention relates to an Mg alloy coil material having excellent surface properties, a method for producing the same, and an Mg alloy plate. In particular, the present invention relates to an Mg alloy coil material having a small surface roughness over the entire length of the coil material.

  Lightweight magnesium alloys (hereinafter referred to as Mg alloys) that are excellent in specific strength and specific rigidity are being studied as constituent materials for various components such as the casings of portable electric and electronic devices such as mobile phones and notebook computers. . Since Mg alloys are poor in plastic workability, casting materials by die casting or thixomold are the mainstream.

  Mg alloy cast material is usually a rolled material obtained by rolling the cast material, a processed material obtained by further polishing the rolled material, and a plastic work obtained by subjecting this processed material to further plastic working such as press working. By using the material, the mechanical strength is improved. In Patent Document 1, regarding rolling of a base material plate such as a cast material, a lubricant may be applied to the surface of the base material plate before rolling in order to reduce friction between the rolling roll and the base material plate. Are listed. Patent Document 2 describes that an Mg alloy rolled material is subjected to polishing, and a typical example of this polishing is wet belt type polishing.

JP 2006-016656 A JP 2009-120877 A

  In the rolling process, when a base material plate coated with a lubricant is rolled, seizure of the lubricant occurs on the surface of the rolled material, resulting in surface deterioration of the rolled material. Therefore, in order to remove this seizure, the rolled material is generally subjected to polishing. However, when polishing is performed, a polishing mark resulting from the polishing is generated on the surface of the polished workpiece. For example, when polishing with a grindstone, the surface roughness of the work material is set to a desired roughness by changing the grain size of the abrasive grains of the grindstone. The polishing marks corresponding to the grain size of the abrasive grains are large and small. Regardless of this, a plurality of streaks appear on the surface of the workpiece along the longitudinal direction of the workpiece. If a polishing mark is generated on the workpiece, cracks may occur along the polishing mark in plastic processing such as subsequent press processing. Further, in the polishing process, when the object to be polished is an active substance such as an Mg alloy, there is a problem that the Mg polishing powder is difficult to handle.

  In the rolling process, during rolling, both sides of the base plate are less restrained in the width direction, so that material flow in the width direction of the base plate occurs and material flow in the longitudinal direction decreases. A crack called an edge crack occurs on the side. Edge cracks that have occurred on both sides of the rolled material must be removed after the end of rolling, and this is also a cause of reduced yield.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a substantially smooth surface over the entire length of the coil material without subjecting the Mg alloy coil material to polishing. An object of the present invention is to provide an Mg alloy coil material having excellent surface properties.

  Another object of the present invention is to provide a method for producing an Mg alloy coil material, which can efficiently produce the Mg alloy coil material of the present invention.

  Furthermore, another object of the present invention is to provide an Mg alloy plate made of an Mg alloy coil material.

  The present invention achieves the above object by contriving the rolling process.

[Mg alloy coil material of the present invention]
The Mg alloy coil material of the present invention relates to an Mg alloy coil material obtained by winding a long rolled material made of an Mg alloy. And the difference of each surface roughness Rz in the longitudinal direction and width direction of a rolling material is 5 micrometers or less over the full length of the said rolling material.

  In the present invention, the length of the rolled material means the following. When the total length of the rolled material is less than 50 m, the trimming material obtained by cutting 10% of the total length from both ends is cut into lengths corresponding to 10% of the total length of the trimming material, thereby producing sheet pieces. For each of these sheet pieces, take a central portion in the width direction at an arbitrary location, exist on a straight line in the width direction passing through the central portion, and a point at a distance of 20 mm from each edge portion and the central portion. A total of three measurement areas are provided, and all measurement areas satisfy the above requirements. On the other hand, when the total length of the rolled material is 50 m or more, a sheet piece is produced by cutting every 10 m of the trimming material with respect to the trimming material cut at 5 m from both ends. Each of these sheet pieces is provided with a measurement region in the same manner as described above, and all the measurement regions satisfy the above-mentioned definition.

  Each surface roughness Rz (maximum height: distance from the lowest position to the highest position, = maximum height Rmax) in the longitudinal direction and the width direction of the rolled material conforms to JIS B 0601 (2001) in the above measurement area. Then, it can be measured using a stylus type surface roughness measuring instrument (manufactured by Mitutoyo Corporation). The measurement length is arbitrarily the same length (4 mm here) along each of the longitudinal direction and the width direction of the rolled material.

  In all the above measurement areas, the difference in surface roughness Rz between the longitudinal direction and the width direction of the rolled material is 5 μm or less, so that the surface is substantially smooth and excellent in surface properties over the entire length of the rolled material. It can be said that. And when the surface property of a rolled material is excellent, it can prevent that a crack arises when plastic processing, such as press work, is given to a rolled material.

  In the Mg alloy coil material of the present invention, each surface roughness Rz in the longitudinal direction and the width direction of the rolled material is preferably 10 μm or less.

  When the surface roughness Rz in the longitudinal direction and the width direction of the rolled material is 10 μm or less, more excellent surface properties and excellent metallic luster can be obtained.

  In the Mg alloy coil material of the present invention, the peak strength height of carbon when the surface of the rolled material is analyzed by EDX (Energy-dispersive X-ray Spectroscopy) is 5% or less of the peak strength height of Mg. It is preferable.

  Conventionally, a lubricant used in rolling is generally composed of an organic material such as fat or alcohol, and carbon is included as a constituent element of the organic material. Therefore, carbon resulting from the lubricant adheres to the surface of the rolled material. However, almost no carbon is adhered to the surface of the Mg alloy coil material of the present invention, and the surface properties are excellent.

  The Mg alloy constituting the Mg alloy coil material of the present invention includes, as additive elements, Al, Zn, Mn, Si, Ca, Be, Sr, Y, Cu, Ag, Sn, Li, Zr, Ce and rare earth elements ( An alloy containing at least one element selected from (excluding Y and Ce) in total of 7.3% by mass or more, with the balance being Mg and impurities.

  In particular, Mg-Al alloys containing Al are excellent in corrosion resistance and mechanical properties such as strength and plastic deformation resistance, and these effects tend to increase as the Al content increases. Accordingly, the Al content is preferably 4.5% by mass or more, and more preferably 7% by mass or more. However, if the Al content exceeds 12% by mass, the plastic workability is lowered, so the upper limit is preferably 12% by mass, and more preferably 11% by mass. Further, among the elements listed above, when elements other than Al are included, the total content is preferably 0.01% by mass or more and 10% by mass or less, and particularly preferably 0.1% by mass or more and 5% by mass or less. Examples of the impurity include Fe and Ni. The rare earth element content is preferably 0.1% by mass or more, and in particular, the Y content is preferably 0.5% by mass or more.

  As a more specific composition, the Mg-Al alloy is, for example, an AZ alloy (Mg-Al-Zn alloy, Zn: 0.2 mass% to 1.5 mass%), an AM alloy (Mg-Al- Mn-based alloy, Mn: 0.15 mass% to 0.5 mass%), Mg-Al-RE (rare earth element) -based alloy, AX-based alloy (Mg-Al-Ca-based alloy, Ca: 0.2 mass% to 6.0 mass%), AJ-based alloys (Mg—Al—Sr-based alloys, Sr: 0.2 mass% to 7.0 mass%) and the like can be mentioned. In particular, a form containing Al more than 7.3% by mass and 12% by mass or less, more specifically, an Mg-Al based alloy containing Al 8.3% to 9.5% by mass and Zn 0.5% to 1.5% by mass, typical The AZ91 alloy is preferable because of its excellent strength and corrosion resistance.

  The Mg alloy coil material of the present invention is obtained by cutting the Mg alloy coil material of the present invention into a predetermined length.

  Since the Mg alloy coil material of the present invention has a substantially smooth surface and excellent surface properties over the entire length, an Mg alloy plate having excellent mechanical strength can be obtained.

[Method for producing Mg alloy coil material of the present invention]
The Mg alloy coil material of the present invention described above can be produced by the following method for producing the Mg alloy coil material of the present invention.

  The manufacturing method of the Mg alloy coil material of the present invention includes a step of sandwiching a long material made of Mg alloy from both sides with a long metal material other than Mg alloy, and a material sandwiched between the metal materials. A rolling process for rolling together with the metal material, and a peeling process for peeling the metal material from the rolled material after rolling. And the rolled raw material (rolled material) is wound up and a Mg alloy coil material is manufactured.

  By sandwiching a long material made of Mg alloy to be rolled with a metal material made of other than the Mg alloy, it is possible to prevent the lubricant from being seized into the Mg alloy material. Although the lubricant is baked on the metal material, the metal material is peeled off from the rolled material (rolled material) in the peeling step, so that there is no seizure of the lubricant on the rolled material. Therefore, it is not necessary to polish the rolled material. By omitting the polishing process, it is possible to prevent the occurrence of polishing marks due to the polishing process, and it is possible to prevent the occurrence of cracks in the subsequent plastic processing such as press processing. Further, by omitting the polishing process, there is no post-processing of the Mg polishing powder, which is difficult to handle, and it is possible to easily shift to plastic processing such as subsequent press processing. Furthermore, by sandwiching the material to be rolled with a metal material, both sides of the material can be fixed, the restraint in the width direction of both sides of the material is strengthened, and edge cracking of the rolled material can be prevented. Therefore, the frequency of performing processing such as removal of edge cracks after rolling can be reduced, and productivity can be improved.

  According to the manufacturing method of the Mg alloy coil material of the present invention, by omitting the polishing process, it is possible to prevent the occurrence of polishing marks due to the polishing process, and substantially the entire surface of the coil material. Therefore, it is possible to efficiently obtain a Mg alloy coil material that is smooth and has excellent surface properties.

  As one form of this invention, the said rolling process performs the reverse rolling of several passes in the state which pinched | interposed the said raw material from the both surfaces, and the form which the said peeling process performs after the completion | finish of the last pass of the said rolling is mentioned. It is done.

  The above rolling is reverse rolling (a rolling roll is sandwiched between a pair of reels, and the reels are reciprocated by alternately switching between feeding and winding and reversing the rotation direction of the coil material. If a method of rolling and rolling is used, a rolled material having a small thickness can be obtained. Furthermore, the average crystal grain size of the structure constituting the rolled material can be reduced, and plastic workability such as subsequent press working can be enhanced. The number of passes, the reduction rate of each pass, and the total reduction rate can be appropriately selected so that a rolled sheet having a desired thickness can be obtained. During reverse rolling, both surfaces of the material are sandwiched between metal materials, and the metal material is peeled off after the end of the final pass of rolling, so that it is possible to prevent the lubricant from being baked on the surface of the rolled material. Moreover, the edge crack of the raw material during rolling can be prevented.

  As one form of this invention, the said peeling process peels off the front-end | tip of the said metal material with a peeling means, and peels over the full length by applying tension | tensile_strength to the peeled metal material.

  After peeling the tip of the metal material from the rolled material by a predetermined length peeling means, the peeling means is separated from the rolled material, and the metal material is peeled from the remainder of the rolled material by applying tension to the metal material. Generation of wrinkles due to the peeling means on the surface can be prevented. And since a metal material peels with tension | tensile_strength, a rolling material can be wound up in coil shape without slack.

  The Mg alloy coil material of the present invention has a substantially smooth surface and excellent surface properties over the entire length. Therefore, it is possible to prevent cracks from occurring when plastic processing such as subsequent press processing is performed.

  Since the manufacturing method of the Mg alloy coil material of the present invention can omit the polishing process, it is possible to prevent the generation of polishing marks due to the polishing process. In addition, since the material to be rolled is sandwiched between metal materials, edge cracks that occur during rolling can be reduced or eliminated. Furthermore, there is no post-treatment of the Mg polishing powder, which is difficult to handle, and it is possible to easily shift to subsequent plastic working. Therefore, the Mg alloy coil material of the present invention can be efficiently manufactured by the method of manufacturing the Mg alloy coil material of the present invention.

It is a schematic diagram explaining the rolling method of the Mg alloy coil material which concerns on embodiment.

<Embodiment>
A method for producing an Mg alloy coil material according to an embodiment of the present invention will be described with reference to FIG. In this manufacturing method, a long metal material 2 made of a material other than an Mg alloy is sandwiched between both sides of the long material 1 made of an Mg alloy, and the material 1 sandwiched between the metal material 2 is a metal material 2 A rolling process for rolling the whole and a peeling process for peeling the metal material 2 from the rolled material after rolling. Then, the rolled material (rolled material 5) is wound on a winding drum 11 to produce an Mg alloy coil material. Hereinafter, each process will be described in detail. The same code | symbol in a figure shows the same name thing.

[Pinching process]
(Mg alloy material)
The Mg alloy material 1 is formed by closely winding a long material made of a single Mg alloy formed by continuous casting such as twin roll casting around a feeding drum 10. The length of the material 1 is preferably 50 m or more, more preferably 100 m or more. The thickness of the material 1 is preferably 6 mm or less, and more preferably 4 mm or less, because segregation is likely to occur if it is too thick. As the Mg alloy material 1, in addition to twin roll casting, for example, a material formed by a continuous casting method such as twin belt casting or belt and wheel casting can be used. Furthermore, the obtained cast material may be subjected to a heat treatment (solution treatment) for homogenizing the composition.

  Mg alloy composing Mg alloy material 1 includes Al, Zn, Mn, Si, Ca, Be, Sr, Y, Cu, Ag, Sn, Li, Zr, Ce and rare earth elements (Y, Ce) as additive elements. In particular, an alloy containing at least one element selected from the group consisting of 7.3% by mass and the balance of Mg and impurities. Specifically, AZ31, AZ61, AZ91 etc. for AZ series alloys in ASTM standards, AM60 etc. for AM series alloys, Mg-Al-RE (rare earth element) series alloys, AX series alloys, AJ series alloys, etc. Mg alloys can be used. In particular, an Mg-Al alloy, typically an AZ91 alloy, is preferable because it has excellent strength and corrosion resistance.

(Metal material)
The metal material 2 is formed by winding a long material made of a material other than the Mg alloy around the supply reel 20. As the metal constituting the metal material 2, it is preferable to use a metal having high ductility and excellent workability. For example, Al, Cu, alloys thereof, and the like can be given. In particular, when Al is used as the metal material 2, it can be expected to improve the formability of the Mg alloy material 1, and it is effective in improving the corrosion resistance of the Mg alloy material 1. Examples of Al or an alloy thereof include pure Al, Al—Cu alloy, Al—Mn alloy, Al—Si alloy, Al—Mg alloy and the like. The metal material 2 preferably has an elongation of 10% or more and a Vickers hardness of 100 or less.

  The length of the metal material 2 in the longitudinal direction is preferably equal to or longer than that of the Mg alloy material 1. The length in the width direction of the metal material 2 is also preferably equal to or longer than the Mg alloy material 1. Since the above lengths of the metal material 2 are equal to or greater than the respective lengths of the Mg alloy material 1, the entire surface of the Mg alloy material 1 can be sandwiched between the metal materials 2, and the width direction of both sides of the Mg alloy material 1 You can also strengthen the restraint. The thickness of the metal material 2 is preferably 0.1 to 1.0 mm. When the thickness of the metal material 2 is 0.1 mm or more, the rolled metal material 2 can be wound around the take-up reel 21 without being broken in the peeling step described later. On the other hand, when the thickness of the metal material 2 is 1.0 mm or less, the Mg alloy material 1 sandwiched between the metal materials 2 can be sufficiently rolled in the rolling process described later. Therefore, the thickness of the metal material 2 is preferably in the above range, and more preferably 0.1 to 0.5 mm. The Mg alloy material 1 often needs to be preheated in order to perform warm rolling, and is preferably sandwiched after being heated to a temperature of 250 ° C. or lower. By heating at 250 ° C. or lower, it is possible to suppress thermal deterioration of the rolling roll 3 or suppress the seizure of the lubricant to the surface of the metal material 2 in the rolling process described later. When the thickness of the metal material 2 is thick (over 1.0 mm), the heat capacity increases, and depending on the temperature of the Mg alloy material 1 and the metal material 2, when the metal material 2 comes into contact with the Mg alloy material 1, the Mg alloy Since the material 1 may be cooled and the plastic workability may be lowered, it is preferable that the metal material 2 is also preheated by heating means such as a heater before the Mg alloy material 1 is sandwiched. On the other hand, when the thickness of the metal material is thin, for example, 0.1 to 0.5 mm, the Mg alloy material 1 can be sandwiched without heating the metal material 2.

  Since the Mg alloy material 1 is sandwiched from both sides by the metal material 2, two metal materials 2 wound around the feeding reel 20 are necessary. Each metal material 2 is symmetrically arranged with the Mg alloy material 1 as the center so as to be opposed to the front and back surfaces of the Mg alloy material 1. Each metal material 2 and the Mg alloy material 1 are rewound, respectively, are sequentially drawn out from the feeding reel 20 and the feeding drum 10, respectively, and the Mg alloy material 1 is sandwiched from both surfaces by the metal material 2, and the process proceeds to the rolling process described later.

[Rolling process]
(Rolling roll)
The rolling roll 3 is composed of a pair of rolls, and each roll is provided with a heating means (not shown) such as a heater, and the rolling roll 3 can be heated by this heating means. When rolling, it is preferable to heat the rolling roll 3 at a temperature of 150 to 300 ° C. by this heating means. By heating at 150 ° C. or higher, the Mg alloy material 1 can be sufficiently heated. On the other hand, by heating at 300 ° C. or less, thermal deterioration of the rolling roll can be suppressed, and seizure of the lubricant on the surface of the metal material 2 can be suppressed. By heating at a temperature of 150 to 300 ° C., it is possible to suppress that one of the Mg alloy material 1 and the metal material 2 is unevenly rolled, and both can be equally rolled. By moving the distance between the rolls of the rolling roll 3, a desired thickness of the rolled material 5 can be obtained.

(lubricant)
In order to reduce friction between the rolling roll 3 and the metal material 2 sandwiching the Mg alloy material 1, a lubricant (not shown) is applied to the entire outer surface of the metal material 2 before rolling. As this lubricant, generally, a rolling oil composed of an organic material such as fat or alcohol can be used.

  If reverse rolling is used in the rolling process, a rolled material 5 having a small thickness can be obtained. Furthermore, the average crystal grain size of the structure constituting the rolled material 5 can be reduced, and plastic workability such as subsequent press working can be improved. As this reverse rolling apparatus, a form provided with a reverse drum (not shown) symmetrically arranged on both sides around a rolling roll made of a pair of rolls can be mentioned. Each drum can rotate in both directions, and any of them can feed and take up. By reversing the rotation direction of both drums and alternately switching between feeding and winding, the Mg alloy material sandwiched between metal materials with the rolling direction reversed for each pass while reciprocating between both drums. Can be rolled. In the rolling process, the Mg alloy material 1 is rolled in a plurality of passes while being sandwiched between the metal materials 2. The number of passes, the reduction rate of each pass, and the total reduction rate can be appropriately selected so that the rolled material 5 having a desired thickness can be obtained.

[Peeling process]
(Peeling means)
After the rolling step, the metal material 2 is peeled off from the rolled material (rolled material 5) by a peeling means. In this example, the blade 4 is used as the peeling means. The blade 4 is installed on both sides of the rolled material 5 and is movable. First, the blade 4 is installed at the joint interface between the metal material 2 and the rolled material 5 so as to be in contact with both, and the tip of the metal material 2 is peeled from the rolled material 5 by the blade 4 having a predetermined length. Each metal material 2 peeled from both surfaces of the rolled material 5 is wound around a take-up reel 21 that is symmetrically arranged opposite to the front and back surfaces of the rolled material 5 with the rolled material 5 as the center. After winding the metal material 2 to the take-up reel 21 to some extent, next, the blade 4 is separated from the rolled material 5 to be non-contact, and the remaining metal material 2 is evenly tensioned in the longitudinal direction of the metal material 2 To peel from the rolled material 5. Separation by applying tension to the blade 4 and the metal material 2 is performed simultaneously on the front and back surfaces of the rolled material 5. By winding the metal material 2 on the take-up reel 21, tension can be applied to the metal material 2, and the rolled material 5 can be wound on the take-up drum 11 without slack. Further, by making the blade 4 in non-contact with the rolled material 5, it is possible to prevent the generation of wrinkles due to the blade 4 on the surface of the rolled material 5. In the above description, the blade 4 is separated from the rolled material 5 and made non-contact in the middle of the peeling process. However, the metal material 2 may be peeled from the rolled material 5 by the blade 4 in a state where both are in contact with each other. In this case, the blade 4 is preferably made of a material (for example, PTFE (polytetrafluoroethylene) or the like) that does not generate wrinkles due to contact with the blade 4 on the surface of the rolled material 5.

  When reverse rolling is performed in the rolling process, the peeling process is performed after the final pass of rolling.

[Winding process]
After the peeling step, the rolled material 5 is wound around a winding drum 11 to form an Mg alloy coil material. The inner diameter and outer diameter of the Mg alloy coil material can be appropriately selected according to the length and thickness of the rolled material 5, for example. However, if the inner diameter is too small or the rolled material is too thick, the rolled material 5 may be cracked when the rolled material 5 is taken up. Therefore, the inner diameter is preferably 400 mm or more.

[Function and effect]
By sandwiching the Mg alloy material 1 with the metal material 2 in the sandwiching process, it is possible to prevent the lubricant from being seized into the Mg alloy material 1 in the rolling process. Although the lubricant is baked onto the metal material 2, the metal material 2 is peeled off from the rolled Mg alloy material (rolled material 5) in the peeling step, so that there is no seizure of the lubricant on the rolled material 5. Therefore, it is not necessary to polish the rolled material 5, and it is possible to prevent the occurrence of polishing marks due to the polishing process. Therefore, it can prevent that a crack arises in plastic processing, such as subsequent press processing. In addition, by sandwiching the Mg alloy material 1 with the metal material 2, both sides of the material 1 can be fixed, the restraint in the width direction of both sides of the material 1 is strengthened, and edge cracking of the rolled material 5 can be prevented. .

  According to the manufacturing method of the Mg alloy coil material, since the polishing process can be omitted, it is possible to prevent the occurrence of polishing marks due to the polishing process, and to substantially reduce the surface over the entire length of the coil material. Therefore, it is possible to efficiently obtain a Mg alloy coil material that is smooth and has excellent surface properties.

<Test example>
An Mg alloy coil material obtained by winding a long rolled material made of Mg alloy was manufactured by the manufacturing method of the above-described embodiment, and the surface properties of the rolled material were examined over the entire length of the rolled material. Specific test conditions are shown below.

[Example]
Mg alloy coil material Composition: AZ91 material (Mg-8.7 mass% Al-0.65 mass% Zn)
Dimensions: Width 250mm x Length 200m x Thickness 4mm
Metal material Material: A6061P (In the case of Al alloy, 6000 series specified in JIS H 4000 (1999))
Dimensions: Width 250mm x Length 200m x Thickness 100μm
Rolling process Reduction ratio: 10-25% / pass Number of passes: 8 passes
Heating temperature of Mg alloy coil material: 250 ℃
Roll temperature: 250 ℃

[result]
Each characteristic of the Mg alloy coil material obtained by the rolling process in the examples is shown below.

(Surface roughness)
The obtained Mg alloy coil material (rolled material) is rewound, and the trimming material cut 5 m from both ends is cut every 10 m to produce a sheet piece. For each of these sheet pieces, take a central portion in the width direction at an arbitrary location, exist on a straight line in the width direction passing through the central portion, and a point at a distance of 20 mm from each edge portion and the central portion. A total of three measurement areas will be provided. In these measurement areas, in accordance with JIS B 0601 (2001), using a stylus type surface roughness measuring instrument (manufactured by Mitutoyo), a length of 4 mm along each of the longitudinal direction and the width direction of the rolled material. Was measured. As a result, in all measurement regions, the difference in the surface roughness Rz between the longitudinal direction and the width direction of the rolled material was 5 μm or less. And the surface roughness Rz in the longitudinal direction and the width direction of the rolled material was in the range of 2 to 10 μm and 2 to 10 μm, respectively. Further, the surface of the rolled material was in a matte-like glossless state.

(Glossiness)
The surface gloss measurement was carried out according to JIS Z 8741 (1997) using a (Nippon Denshoku gloss meter) at a light projecting / receiving angle of 20 °. In the measurement area, three points were measured along the longitudinal direction and the width direction of the rolled material. As a result, in all measurement regions, the glossiness in the longitudinal direction and the width direction of the rolled material averaged 16.2% and 16.8%, respectively.

(Peak intensity of carbon)
In the above measurement region, the surface of the rolled material was subjected to EDX analysis, and the peak intensity height of carbon and the peak intensity height of Mg were compared. As a result, in all measurement regions, the peak intensity height of carbon was 5% or less of the peak intensity height of Mg.

  From the above test results, it was confirmed that the Mg alloy coil material of the present invention can provide a Mg alloy coil material having a substantially smooth surface and excellent surface properties over the entire length of the rolled material.

  Furthermore, the obtained Mg alloy coil material (width 250mm x length 1300m x thickness 0.6mm, surface roughness Rz: longitudinal direction 6μm, width direction 6μm) is warm pressed (material heating temperature 250 ° C, mold) To obtain a pressing member having a cross-section]. As a result, press working could be performed without causing cracks.

  From the above results, the plastic work material formed by subjecting the Mg alloy coil material of the present invention, which has a substantially smooth surface and excellent surface properties, to the entire length, is subjected to plastic working such as press working. It can be said that the strength is excellent and the productivity of the Mg alloy member is excellent.

  The above-described embodiment can be appropriately changed without departing from the gist of the present invention, and is not limited to the above-described configuration. For example, the composition of the Mg alloy (the type and content of elements contained), the thickness, width, and length of the Mg alloy plate, and the production conditions (material of the metal material, rolling conditions, etc.) can be changed as appropriate.

  The Mg alloy coil material and the Mg alloy plate of the present invention are Mg alloy members subjected to various plastic processing such as press working, forging and bending, for example, portable and small casings for electric and electronic devices. Thus, it can be suitably used as a material for members of various fields where high strength and light weight are desired, such as components of various electrical and electronic devices, and aircraft and automobile bodies. The manufacturing method of the Mg alloy coil material of the present invention can be suitably used for manufacturing the Mg alloy coil material of the present invention.

1 Mg alloy material 10 Feeding drum 11 Winding drum
2 Metal 20 Feed reel 21 Take-up reel
3 Rolling roll
4 blade
5 Rolled material

Claims (9)

An Mg alloy coil material obtained by winding a long rolled material made of Mg alloy,
The Mg alloy coil material, wherein a difference in surface roughness Rz between the longitudinal direction and the width direction of the rolled material is 5 µm or less over the entire length of the rolled material.   2. The Mg alloy coil material according to claim 1, wherein each of the surface roughnesses Rz in the longitudinal direction and the width direction of the rolled material is 10 μm or less.   3. The Mg alloy coil material according to claim 1, wherein the peak intensity height of carbon when the surface of the rolled material is subjected to EDX analysis is 5% or less of the peak intensity height of Mg.   The Mg alloy is selected from Al, Zn, Mn, Si, Ca, Be, Sr, Y, Cu, Ag, Sn, Li, Zr, Ce and rare earth elements (excluding Y and Ce) as additive elements. The Mg alloy coil material according to any one of claims 1 to 3, wherein the Mg alloy coil material contains at least one element in total of 7.3% by mass or more, with the balance being Mg and impurities.   The Mg alloy coil material according to any one of claims 1 to 4, wherein the Mg alloy contains 8.3 mass% to 9.5 mass% of Al as an additive element.   An Mg alloy plate obtained by cutting the Mg alloy coil material according to any one of claims 1 to 5 to a predetermined length. A method for producing a Mg alloy coil material, which is a long rolled material made of Mg alloy and wound to produce a Mg alloy coil material,
A sandwiching process of sandwiching a long material made of Mg alloy from both sides with a long metal material other than Mg alloy,
A rolling step of rolling the material sandwiched between the metal materials together with the metal material;
A method for producing an Mg alloy coil material, comprising: a peeling step of peeling the metal material from the rolled material after the rolling. The rolling step performs reverse rolling of a plurality of passes in a state where the material is sandwiched between the metal materials from both sides,
8. The method for producing an Mg alloy coil material according to claim 7, wherein the peeling step is performed after the final pass of the rolling.   9. The Mg alloy coil according to claim 7 or 8, wherein the peeling step peels the metal material over the entire length by peeling the tip of the metal material by a peeling means and applying tension to the peeled metal material. A method of manufacturing the material.

Images