JP7164919B2 - METAL MOLDED BODY HAVING A POROUS STRUCTURE ON A SURFACE LAYER AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Description

TECHNICAL FIELD The present invention relates to a metal compact having a porous surface layer and a method for producing the same.

A metal compact having a roughened surface to form a porous structure and a method for producing the same are known.
Patent Document 1 discloses a trunk hole formed in the thickness direction and having an opening on the surface side; It has an internal space which is formed in a vertical direction and does not have an opening on the surface side, and furthermore, a tunnel connection path connecting the open hole and the internal space, and a tunnel connection path connecting the open holes. The invention of a metal compact having a roughened surface layer is described.
Since the surface layer has a complicated porous structure, it can be bonded with a high bonding strength when bonded to a resin, for example.

Patent Literature 2 describes an invention of a laser processing method for a metal surface in which laser scanning is performed multiple times in a crossing direction. The metal surface after processing is said to be characterized by including the bridge structure shown in FIG.

Japanese Patent No. 5998303 Japanese Patent No. 4020957

SUMMARY OF THE INVENTION An object of the present invention is to provide a metal compact having a novel porous structure in its surface layer, and a method for producing the same.

The present invention relates to a metal compact having a porous structure on the surface layer,
The porous structure is
A plurality of grooves of the first group formed on the surface of the metal compact at intervals in the same direction, and a plurality of grooves formed at intervals in a direction perpendicular to or oblique to the grooves of the first group. and the surface of the metal compact has a plurality of islands remaining surrounded by the plurality of first group of grooves and the plurality of second group of grooves. and
The cross-sectional structure in the thickness direction along the grooves of the first group, the cross-sectional structure in the thickness direction along the grooves in the second group, or the cross-sectional structure in the thickness direction of a straight line passing through a plurality of island portions are formed by the upper groove portion and the lower groove portion. A metal molded body having a surface layer portion having a porous structure, which is separated into groove portions and has a portion in which an H-shaped structure having a bridge portion is formed between the upper groove portion and the lower groove portion. A method for producing the same is provided.

Further, the present invention provides a metal molded body having a porous structure in the surface layer,
The porous structure is
A plurality of grooves of the first group formed on the surface of the metal compact at intervals in the same direction, and a plurality of grooves formed at intervals in a direction perpendicular to or oblique to the grooves of the first group. and the surface of the metal compact has a plurality of islands remaining surrounded by the plurality of first group of grooves and the plurality of second group of grooves. and
A cross-sectional structure in the thickness direction along the first group of grooves, a cross-sectional structure in the thickness direction along the second group of grooves, or a cross-sectional structure in the thickness direction of a straight line passing through a plurality of islands,
a portion separated into an upper groove portion and a lower groove portion and formed with an H-shaped structure having a bridging portion between the upper groove portion and the lower groove portion;
A ladder structure is formed which is divided into an upper groove portion, an interrupted groove portion and a lower groove portion, has a first bridge portion between the upper groove portion and the middle groove portion, and has a second bridge portion between the middle groove portion and the lower groove portion. Provided are a metal molded article having a porous structure on the surface layer thereof, and a method for producing the same.

Since the metal compact having a porous structure according to the present invention has a complicated porous structure in the surface layer, it has a high It can be joined by joining force.

FIG. 2 is a conceptual diagram of the surface of the metal compact having a porous structure according to the present invention. Sectional drawing of X1, X2, Y1, or Y2 direction of FIG. 1 is a SEM photograph of the surface of a metal compact having a porous structure produced in Example 1. FIG. SEM photograph of the surface of the metal compact having a porous structure produced in Example 2. FIG. An X-ray CT photograph of the cross-sectional structure in the X1 direction of FIG. 1 (FIG. 3). An X-ray CT photograph of the cross-sectional structure in the X2 direction of FIG. 1 (FIG. 3). An X-ray CT photograph of the cross-sectional structure in the Y1 direction of FIG. 1 (FIG. 3). An X-ray CT photograph of the cross-sectional structure in the Y2 direction of FIG. 1 (FIG. 3).

<Metal compact having a porous structure on the surface layer>
The metal compact 1 shown in FIGS. 1 and 2 has a porous structure on the surface layer.
The porous structure is formed on the entire surface or a part of the surface of the metal compact 1, and includes a plurality of first group grooves 10 formed at intervals in the same direction (X direction) and a first group of grooves 10 formed at intervals. It has a plurality of second group grooves 11 formed at intervals in a direction (Y direction) perpendicular to or oblique to the first group of grooves 10, and furthermore, the surface 2 of the metal compact 1 has a plurality of second grooves. It has a plurality of island portions 12 remaining surrounded by a group of grooves 10 and a plurality of second group of grooves 11 .
It should be noted that FIG. 1 is used only to describe the arrangement of the first group of grooves 10, the second group of grooves 11, and the island portions 12. As shown in FIG.

The metal that can be used for the metal compact is not particularly limited, and can be appropriately selected according to the application.
For example, metals such as iron, stainless steel, aluminum, titanium, copper, magnesium, nickel, zinc, chromium, gold, and silver, and alloys of these metals with known other metals can be used.

The depth (d in FIG. 2) of the surface layer from the surface of the metal compact 1 is preferably in the range of 10 to 1000 μm, more preferably in the range of 50 to 500 μm.

The porous structure of the metal molded body 1 has a cross-sectional structure in the thickness direction along the first group of grooves 10 (X1 direction), and a plurality of island portions 12 are formed in the same direction as the direction along the first group of grooves 10. In the same direction as the cross-sectional structure in the thickness direction in the passing direction (X2 direction), the cross-sectional structure in the thickness direction in the direction (Y1 direction) along the second group of grooves 11, and the direction along the second group of grooves 11, The cross-sectional structure in the thickness direction (Y2 direction) in the direction (Y2 direction) passing through the plurality of island portions 12 is divided into an upper groove portion 20 and a lower groove portion 21, and a bridging portion is formed between the upper groove portion 20 and the lower groove portion 21. It has a portion in which an H-shaped structure with 30 is formed.
Furthermore, in addition to the H-shaped structure, the porous structure of the metal compact 1 is divided into an upper groove portion 20, an interrupted groove portion 22 and a lower groove portion 21, and a first bridging portion 31 is provided between the upper groove portion 20 and the middle groove portion 22. A ladder structure having a second bridging portion 32 is formed between the intermediate groove portion 22 and the lower groove portion 21 .
Thus, the porous structure of the metal compact 1 has a three-dimensional tunnel passage structure in which the tunnel passages extending in the horizontal direction and the vertical direction are connected in the surface layer.

When the metal molded body 1 of the present invention having a porous surface layer portion has a porous structure, for example, when it is used for the purpose of forming a composite with a resin, the resin enters the inside of the three-dimensional tunnel passage structure. 2, the resin enters both the upper groove portion 20 and the lower groove portion 21 of the grooves 10 of the first group shown in FIG. A large number of such structures exist three-dimensionally.
Therefore, when the metal molded body 1 and the resin molded body are pulled together, resistance is exhibited by the resin and the numerous cross-linking portions 30, so that high bonding strength can be obtained.
On the other hand, in the case of the bridge in the porous structure of Patent Document 1 (Fig. 1), the resin enters only the lower side of the bridge. Therefore, the bonding strength becomes smaller.

<Implant>
The implant of the present invention is composed of the metal compact having a porous structure in the surface layer portion.
The implant has the above-described porous structure on the surface layer of the portion to be bonded to living tissue including bones or teeth.
Implants are used to connect living tissue, including bone or teeth, made of titanium or titanium alloys.
Implants include artificial hip joints (stems, cups), artificial joints such as artificial knee joints, fracture fixation (plates, screws), and artificial tooth roots.

When an implant having a porous structure in the surface layer of the present invention is connected so as to be embedded in the bone, "Creation of bone tissue-compatible implant by nanopulse laser" (Associate Professor Masayoshi Mizutani, Graduate School of Engineering, Tohoku University) , 2011 General Research and Development Grant AF-2011212)”, as described in the left column of page 158, first the calcium phosphates contained in supersaturated body fluids precipitate, and at the same time osteoblasts sense the space. It activates in the sphincter and produces bone components on both the bone and implant surfaces. It is considered that the new bone eventually fills the space between the bone and the implant (the porous structure of the surface of the implant), resulting in a tight and dense bonding state.
The porous structure formed on the surface layer of the implant of the present invention has a complicated structure (three-dimensional tunnel passage structure) as shown in FIG. is expected to act to increase

<Method for producing a metal compact having a porous structure on the surface layer>
A method for producing the metal compact having a porous structure in the surface layer portion will be described. The same manufacturing method is carried out when the metal compact is an implant.
The first step is to continuously irradiate the surface of the metal compact 1 with laser light at intervals in the same direction (X1 direction) to form the first group of grooves 10 .
In the second step, after the first step, the surface of the metal molded body 1 is continuously irradiated with a laser beam at intervals in a direction orthogonal or oblique to the grooves 10 of the first group (Y1 direction). This is the step of forming the second group of grooves 11 .
The grooves 10 of the first group and the grooves 11 of the second group are formed to be orthogonal or oblique to each other, and the angle between the grooves 10 of the first group and the grooves 11 of the second group is 45 to 90 degrees. is preferable, and an angle of 90 degrees or close to 90 degrees is more preferable.

In the production method of the present invention,
(i) The first step and the second step are alternately performed once each, and the total number of times of laser light irradiation is 10 to 40 times (the first step and the second step are each 5 to 20 times). A method of forming a first group of grooves 10 and a second group of grooves 11 by adjusting to
(ii) performing the first step and the second step alternately once, or alternately performing the first step and the second step a plurality of times, and 10 to 40 times in total (5 to 20 times for the first step and the second step, respectively) to form the grooves 10 of the first group and the grooves 11 of the second group. , a method of forming a number of islands 12 .
In the method (ii), the first step and the second step are preferably performed alternately two to four times each. In the method (ii), alternately one laser light irradiation and multiple alternate laser light irradiations may be combined. In that case, the total number of laser light irradiations is 10 to 40 times. (5 to 20 times for each of the first step and the second step).

The method of irradiating laser light is disclosed in Japanese Patent No. 5774246, Japanese Patent No. 5701414, Japanese Patent No. 5860190, Japanese Patent No. 5890054, Japanese Patent No. 5959689, Japanese Unexamined Patent Publication No. 2016-43413, and Japanese Unexamined Patent Publication No. 2016-36884. It can be carried out in the same manner as the continuous irradiation method of laser light described in Japanese Unexamined Patent Application Publication No. 2016-44337.

The energy density should be 1 MW/cm ² or more. The energy density at the time of laser light irradiation can be obtained from the laser light output (W) and the laser light (spot area (cm ² ) (π·[spot diameter/2] ² ). Energy at the time of laser light irradiation. The density is preferably 2 to 1000 MW/cm ² , more preferably 10 to 800 MW/cm ² and even more preferably 10 to 700 MW/cm ² .
The laser beam irradiation speed is preferably 2,000 to 20,000 mm/sec, more preferably 2,000 to 18,000 mm/sec, and even more preferably 3,000 to 15,000 mm/sec.
The laser beam output is preferably 4 to 4000W, more preferably 50 to 2500W, even more preferably 150 to 2000W.
A wavelength of 500 to 11,000 nm is preferred.
A beam diameter (spot diameter) is preferably 5 to 80 μm.
The defocus distance is preferably -5 to +5 mm, more preferably -1 to +1 mm, even more preferably -0.5 to +0.1 mm. Laser irradiation may be performed with the set value of the defocusing distance constant, or laser irradiation may be performed while changing the defocusing distance. For example, during laser irradiation, the defocus distance may be decreased, or may be increased and decreased periodically.
The interval between adjacent grooves 10 in the first group or the interval between adjacent grooves 11 in the second group is preferably 0.01 to 0.2 mm, more preferably 0.03 to 0.15 mm.

When continuously irradiating laser light in the manufacturing method of the present invention,
A substrate (e.g., steel plate, copper plate) consisting of a non-laser-irradiated surface and a material with a higher thermal conductivity than the metal forming the metal compact (implant) (a material with a thermal conductivity of 100 W/m・k or more). , aluminum plate), or (ii) a non-irradiated surface of the metal compact (implant) and a substrate ( For example, a method of contacting with a glass plate) can be applied.
For the method (i), the method described in JP-A-2016-78090 can be applied, and for the method (ii), the method described in JP-A-2016-124024 can be applied.
The method (i) can suppress the temperature rise by dissipating the heat generated when the metal compact (implant) is irradiated with the laser beam.
The method (ii) can suppress heat radiation generated when a metal compact (implant) is irradiated with a laser beam.

When laser light is continuously irradiated in the production method of the present invention, irradiation can be performed while supplying an assist gas selected from air, oxygen, nitrogen, argon, and helium.
By irradiating the laser beam while supplying an assist gas, it is possible to assist in controlling the depth, size and orientation of the holes, suppress the formation of carbides, and control the surface properties. can be done.
For example, argon gas can be selected to prevent surface oxidation, oxygen can be selected to promote surface oxidation, and nitrogen gas can be selected to prevent oxidation and improve surface hardness.

Known lasers can be used in the method of irradiating laser light, and examples thereof include YVO ₄ laser, fiber laser (single mode fiber laser, multimode fiber laser), excimer laser, carbon dioxide laser, ultraviolet laser, YAG lasers, semiconductor lasers, glass lasers, ruby lasers, He--Ne lasers, nitrogen lasers, chelate lasers and dye lasers can be used.

Examples 1 and 2
A plate of pure titanium and 64 titanium (length 30 mm, width 30 mm, thickness 3 mm) was continuously irradiated with laser light under the conditions shown in Table 1 using the following laser device.
In Examples 1 and 2, after performing continuous laser beam irradiation in the first step for forming the first group of grooves (X1 direction) 10 shown in FIG. Continuous irradiation with laser light in the second step for forming was repeated 10 times (total 20 times). The angle between grooves 10 of the first group and grooves 11 of the second group was about 90 degrees.

(laser device)
Oscillator: IPG-Yb fiber; YLR-300-SM
Galvanometer mirror SQUIREEL (manufactured by ARGES)
Focusing system: fc=80mm/fθ=100mm

FIG. 3 shows an SEM photograph of the surface of the pure titanium plate roughened by irradiation with a laser beam, and FIG. 4 shows an SEM photograph of the surface of the 64Ti plate after roughening by irradiation with a laser beam. From the comparison between FIGS. 3 and 4 and FIGS. 1 and 2, grooves 10 of the first group, grooves 11 of the second group, and island portions 20 can be confirmed. Part 31) can also be confirmed.
5 to 8 show X-ray CT photographs of the cross-sectional structure in the thickness direction corresponding to the X1, X2, Y1 and Y2 directions in FIG. 1 of Example 1 (FIG. 3).
FIG. 5 is an X-ray CT photograph of the vertical line portion (X1) passing through the grooves of the first group in the left diagram, and FIG. 6 is an X-ray CT photograph of the vertical line portion (X2) passing through the plurality of island portions in the left diagram. , FIG. 7 is an X-ray CT photograph of the vertical line portion (Y1) passing through the grooves of the second group in the left figure, and FIG. It is a photograph.
From FIGS. 5 to 8, an H-shaped structure and a ladder structure similar to those in FIG. 2 could be confirmed in any cross-sectional structure. Therefore, it was also confirmed that the porous structure of the metal compact of the present invention has a three-dimensional tunnel passage structure. The maximum depths described in Examples 1 and 2 are values obtained from X-ray CT photographs.

The metal molded article of the present invention can be used for manufacturing composites of the metal molded article with resin, rubber, elastomer, other metals, etc., and for implants.

REFERENCE SIGNS LIST 1 metal compact 2 surface of metal compact 10 first group of grooves 11 second group of grooves 12 island portion 20 upper groove portion 21 lower groove portion 22 interruption groove portion 30 bridging portion 31 first bridging portion 32 second bridging portion

Claims (6)

A metal compact having a porous structure in the surface layer,
The porous structure is
A plurality of first group grooves formed on the surface of the metal compact at intervals in the same direction, and a plurality of grooves formed at intervals in a direction perpendicular to or oblique to the first group of grooves. and the surface of the metal compact has a plurality of islands remaining surrounded by the plurality of first group of grooves and the plurality of second group of grooves. and
The cross-sectional structure in the thickness direction along the grooves of the first group, the cross-sectional structure in the thickness direction along the grooves in the second group, or the cross-sectional structure in the thickness direction of a straight line passing through a plurality of island portions are formed by the upper groove portion and the lower groove portion. separated into grooves,
A metal molded body having a surface layer portion having a porous structure, which has a portion formed with an H-shaped structure having a bridging portion between the upper groove portion and the lower groove portion. A metal compact having a porous structure in the surface layer,
The porous structure is
A plurality of first group grooves formed on the surface of the metal compact at intervals in the same direction, and a plurality of grooves formed at intervals in a direction perpendicular to or oblique to the first group of grooves. and the surface of the metal compact has a plurality of islands remaining surrounded by the plurality of first group of grooves and the plurality of second group of grooves. and
A cross-sectional structure in the thickness direction along the first group of grooves, a cross-sectional structure in the thickness direction along the second group of grooves, or a cross-sectional structure in the thickness direction of a straight line passing through a plurality of islands,
It is separated into an upper groove portion and a lower groove portion, and is separated into a portion in which an H-shaped structure having a bridge portion is formed between the upper groove portion and the lower groove portion, an upper groove portion, a middle groove portion and a lower groove portion,
It has a portion formed with a ladder structure having a first bridge portion between the upper groove portion and the middle groove portion, and a second bridge portion between the middle groove portion and the lower groove portion . , a metal compact having a porous structure on the surface layer thereof. 3. The metal compact according to claim 1 or 2, wherein the surface layer has a porous structure in the range of 10 to 1000 μm from the non-roughened surface of the metal compact. The implant according to any one of claims 1 to 3, wherein the surface layer portion is made of a molded metal body having a porous structure,
An implant used for bonding with living tissue including bone or teeth, wherein said implant is made of titanium or a titanium alloy. A method for producing a metal compact having a porous structure in the surface layer portion according to any one of claims 1 to 3,
The surface of the metal compact was continuously irradiated with a continuous wave laser beam at intervals in the same direction at an energy density of 1 MW/cm ² or more at a laser beam irradiation speed of 2,000 to 20,000 mm/sec. a first step of forming a first group of grooves;
Next, with respect to the surface of the metal compact, the energy density is 1 MW/cm ² or more at intervals in the direction orthogonal or oblique to the grooves of the first group, and the irradiation speed of the laser beam is 2,000 to 20,000. a second step of continuously irradiating a continuous wave laser beam at 000 mm/sec to form a second group of grooves;
The first step and the second step are alternately performed once each, or the first step and the second step are alternately performed a plurality of times to obtain the first group of grooves formed in the first step and the second step. The grooves of the first group and the grooves of the second group are formed by adjusting the number of irradiation times of the laser light to each groove of the second group formed in 10 to 50 times in total. , a method for producing a metal compact having a porous surface layer. A method for producing an implant comprising a metal compact having a porous structure in the surface layer portion according to claim 4,
With respect to the surface of the metal molded body for implant made of titanium or titanium alloy, the energy density is 1 MW/cm ² or more at intervals in the same direction, and the laser beam irradiation speed is continuous at 2,000 to 20,000 mm/sec. a first step of continuously irradiating a wave laser beam to form a first group of grooves;
Next, with respect to the surface of the metal molded body for implant, the energy density is 1 MW/cm ² or more at intervals in the direction orthogonal or oblique to the grooves of the first group, and the irradiation speed of laser light is 2,000 to 2,000. a second step of continuously irradiating a continuous wave laser beam at 20,000 mm/sec to form a second group of grooves;
The first step and the second step are alternately performed once each, or the first step and the second step are alternately performed a plurality of times to obtain the first group of grooves formed in the first step and the second step. The grooves of the first group and the grooves of the second group are formed by adjusting the number of irradiation times of the laser light to each groove of the second group formed in 10 to 50 times in total. , a method for producing an implant comprising a metal compact having a porous surface layer.

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