JP2020093352A - METHOD FOR MODIFYING SURFACE OF Co-Cr ALLOY, METHOD OF MANUFACTURING HIGH FATIGUE STRENGTH Co-Cr ALLOY, AND HIGH FATIGUE STRENGTH Co-Cr ALLOY - Google Patents

METHOD FOR MODIFYING SURFACE OF Co-Cr ALLOY, METHOD OF MANUFACTURING HIGH FATIGUE STRENGTH Co-Cr ALLOY, AND HIGH FATIGUE STRENGTH Co-Cr ALLOY Download PDF

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JP2020093352A
JP2020093352A JP2018233570A JP2018233570A JP2020093352A JP 2020093352 A JP2020093352 A JP 2020093352A JP 2018233570 A JP2018233570 A JP 2018233570A JP 2018233570 A JP2018233570 A JP 2018233570A JP 2020093352 A JP2020093352 A JP 2020093352A
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alloy
shot
fatigue strength
high fatigue
phase
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紀之 久森
Noriyuki Hisamori
紀之 久森
元樹 福田
Motoki Fukuda
元樹 福田
悠太 水野
Yuta Mizuno
悠太 水野
祐次 小林
Yuji Kobayashi
祐次 小林
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Sintokogio Ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/10—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of nickel or cobalt or alloys based thereon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
    • B24C1/00—Methods for use of abrasive blasting for producing particular effects; Use of auxiliary equipment in connection with such methods
    • B24C1/10—Methods for use of abrasive blasting for producing particular effects; Use of auxiliary equipment in connection with such methods for compacting surfaces, e.g. shot-peening
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
    • C21D7/04—Modifying the physical properties of iron or steel by deformation by cold working of the surface
    • C21D7/06—Modifying the physical properties of iron or steel by deformation by cold working of the surface by shot-peening or the like
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/47—Burnishing
    • Y10T29/479—Burnishing by shot peening or blasting

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Materials For Medical Uses (AREA)

Abstract

To provide a method for modifying the surface of Co-Cr alloy with the aim of obtaining Co-Cr alloy more excellent in fatigue strength.SOLUTION: The method for modifying the surface of Co-Cr alloy includes a shot-peening process on the Co-Cr alloy by using a shot material containing ZrO.SELECTED DRAWING: Figure 5

Description

本開示は、Ｃｏ−Ｃｒ合金の表面改質方法、高疲労強度Ｃｏ−Ｃｒ合金の製造方法、及び高疲労強度Ｃｏ−Ｃｒ合金に関する。 The present disclosure relates to a surface modification method for a Co—Cr alloy, a method for producing a high fatigue strength Co—Cr alloy, and a high fatigue strength Co—Cr alloy.

インプラント材料として、生体適合性を有するＣｏ−Ｃｒ合金が使用されている。Ｃｏ−Ｃｒ合金はＴｉよりも強度が高いため、脊髄用のピン等の高負荷が掛かる部材の材料として使用される。そのようなＣｏ−Ｃｒ合金に熱処理を施すことにより、その強度を改善する方法が知られている（例えば、特許文献１）。 A biocompatible Co-Cr alloy is used as an implant material. Since the Co-Cr alloy has higher strength than Ti, it is used as a material for a member to which a high load is applied, such as a spinal cord pin. A method of improving the strength of such a Co—Cr alloy by subjecting it to heat treatment is known (for example, Patent Document 1).

特開２０１４−７４２２７号公報JP, 2014-74227, A

インプラント材料は経時劣化等の理由から適時に交換をする必要があるが、交換の都度生体に大きな負荷が掛かるのが現状である。交換頻度を低減するべく、より長期使用に耐えられるインプラント材料の開発が求められる。 The implant material needs to be replaced in a timely manner for reasons such as deterioration over time, but the present situation is that a large load is placed on the living body each time it is replaced. In order to reduce the frequency of replacement, it is necessary to develop implant materials that can withstand longer-term use.

本開示は上記事情に鑑みてなされたものであり、疲労強度により優れるＣｏ−Ｃｒ合金を得るためのＣｏ−Ｃｒ合金の表面改質方法を提供することを目的とする。本開示はまた、そのような高疲労強度Ｃｏ−Ｃｒ合金を製造するための製造方法、及び当該製造方法により得られる高疲労強度Ｃｏ−Ｃｒ合金を提供することを目的とする。 The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a surface modification method of a Co-Cr alloy for obtaining a Co-Cr alloy having more excellent fatigue strength. Another object of the present disclosure is to provide a manufacturing method for manufacturing such a high fatigue strength Co-Cr alloy, and a high fatigue strength Co-Cr alloy obtained by the manufacturing method.

本開示は、Ｃｏ−Ｃｒ合金に対し、ＺｒＯ２を含むショット材を用いてショットピーニング処理する工程を備える、Ｃｏ−Ｃｒ合金の表面改質方法を提供する。 The present disclosure provides a method for modifying the surface of a Co—Cr alloy, the method including a step of subjecting a Co—Cr alloy to a shot peening treatment using a shot material containing ZrO 2 .

本開示はまた、Ｃｏ−Ｃｒ合金に対し、ＺｒＯ２を含むショット材を用いてショットピーニング処理する工程を備える、高疲労強度Ｃｏ−Ｃｒ合金の製造方法を提供する。 The present disclosure also provides a method for producing a high fatigue strength Co—Cr alloy, which includes a step of subjecting a Co—Cr alloy to a shot peening treatment using a shot material containing ZrO 2 .

本開示の表面改質方法及び製造方法の一態様において、ショット材の平均粒径は０．０５〜１．０ｍｍであってもよい。 In one aspect of the surface modification method and the manufacturing method of the present disclosure, the average particle size of the shot material may be 0.05 to 1.0 mm.

本開示はまた、内部から表面にかけてε−ｈｃｐ相が漸増しかつγ−ｆｃｃ相が漸減する、高疲労強度Ｃｏ−Ｃｒ合金を提供する。 The present disclosure also provides a high fatigue strength Co-Cr alloy having an increasing [epsilon]-hcp phase and decreasing [gamma]-fcc phase from the inside to the surface.

本開示の合金の一態様において、表面のビッカース硬さ（ＨＶ）が５００以上であってもよい。 In one aspect of the alloy of the present disclosure, the surface Vickers hardness (HV) may be 500 or more.

本開示によれば、疲労強度により優れるＣｏ−Ｃｒ合金を得るためのＣｏ−Ｃｒ合金の表面改質方法を提供することができる。また、本開示によれば、そのような高疲労強度Ｃｏ−Ｃｒ合金を製造するための製造方法、及び当該製造方法により得られる高疲労強度Ｃｏ−Ｃｒ合金を提供することができる。 According to the present disclosure, it is possible to provide a surface modification method of a Co-Cr alloy for obtaining a Co-Cr alloy having more excellent fatigue strength. Moreover, according to this indication, the manufacturing method for manufacturing such a high fatigue strength Co-Cr alloy, and the high fatigue strength Co-Cr alloy obtained by the said manufacturing method can be provided.

本開示により、高疲労強度化が可能で高寿命であるインプラントの製作が可能となる。また、ショットピーニングによる表面改質は材料の成分を変更するものではないため、インプラント材料としての承認基準もクリアし易いと考える。 According to the present disclosure, it is possible to manufacture an implant having high fatigue strength and long life. In addition, since surface modification by shot peening does not change the composition of the material, it is considered that the approval criteria as an implant material can be easily cleared.

ショットピーニング処理前後の供試材の表面粗さＲｚを示す図である。It is a figure which shows the surface roughness Rz of the sample material before and behind a shot peening process. ショットピーニング処理前後の供試材のＸＲＤ回折結果を示す図である。It is a figure which shows the XRD diffraction result of the sample material before and behind a shot peening process. ショットピーニング処理後の供試材におけるε相の割合を示す図である。It is a figure which shows the ratio of (epsilon) phase in the sample material after a shot peening process. ショットピーニング処理前後の供試材のＥＢＳＤ観察結果を示す図である。It is a figure which shows the EBSD observation result of the sample material before and behind a shot peening process. ショットピーニング処理前後の供試材のビッカース硬さ（ＨＶ）を示す図である。It is a figure which shows the Vickers hardness (HV) of the sample material before and behind a shot peening process.

以下に、本開示を実施するための最良の形態について説明する。 The best mode for carrying out the present disclosure will be described below.

［Ｃｏ−Ｃｒ合金の表面改質方法］
本実施形態のＣｏ−Ｃｒ合金の表面改質方法は、Ｃｏ−Ｃｒ合金に対し、ＺｒＯ２を含むショット材を用いてショットピーニング処理する工程を備える。 [Co-Cr alloy surface modification method]
The surface modification method of the Co—Cr alloy of the present embodiment includes a step of subjecting the Co—Cr alloy to a shot peening treatment using a shot material containing ZrO 2 .

本実施形態の表面改質方法は、Ｃｏ−Ｃｒ合金の相変態（γ−ｆｃｃ相からε−ｈｃｐ相への加工誘起マルテンサイト変態）を利用して、合金表面の改質を行うものである。熱伝導性の低いＺｒＯ２を主成分としたジルコニア材をショット材として用いることで、ショットピーニングの熱エネルギーを効率的に合金側に供し易くなるため、熱処理と同等の処理を局所的かつ瞬間的に合金に対して施すことができると考えられる。本実施形態の表面改質方法によれば、Ｃｏ−Ｃｒ合金の表面近傍を選択的にε相に相変態させることで、表面近傍が高強度でありながら内部の靭性が維持されている材料（傾斜材料）を実現することができる。外部からの負荷に対する強さを有し、かつ柔軟性をも有しているこのような材料は、疲労強度に優れる（高疲労強度）材料である。 The surface modification method of the present embodiment utilizes the phase transformation of a Co—Cr alloy (work-induced martensite transformation from the γ-fcc phase to the ε-hcp phase) to reform the alloy surface. .. By using a zirconia material containing ZrO 2 having a low thermal conductivity as a main component as a shot material, it becomes easy to efficiently supply the heat energy of shot peening to the alloy side. It is believed that the above can be applied to the alloy. According to the surface modification method of the present embodiment, by selectively transforming the vicinity of the surface of the Co—Cr alloy into the ε phase, a material having high strength in the vicinity of the surface but maintaining the internal toughness ( (Gradient material) can be realized. Such a material having strength against external load and also having flexibility is a material having excellent fatigue strength (high fatigue strength).

Ｃｏ−Ｃｒ合金としてはＣｏ−Ｃｒ−Ｍｏ合金を用いることができ、特にＡＳＴＭ Ｆ１５３７に準拠したＣｏ−２８Ｃｒ−６Ｍｏ合金を用いることができる。このＣｏ−２８Ｃｒ−６Ｍｏ合金は、Ｃｏを主成分として含み、Ｃｒ含有量が２６．３〜３０．０質量％、Ｍｏ含有量が５．０〜７．０質量％であり、その他成分としてＮｉ、Ｍｎ、Ｓｉ、Ｃ、Ｆｅ、Ｎ等を微量に含む。このようなＣｏ−Ｃｒ合金は生体適合性があり、インプラント等の医療用途に用いることができる。 As the Co-Cr alloy, a Co-Cr-Mo alloy can be used, and in particular, a Co-28Cr-6Mo alloy according to ASTM F1537 can be used. This Co-28Cr-6Mo alloy contains Co as a main component, has a Cr content of 26.3 to 30.0 mass% and a Mo content of 5.0 to 7.0 mass%, and has Ni as another component. , Mn, Si, C, Fe, N, etc. are contained in a trace amount. Such a Co—Cr alloy is biocompatible and can be used for medical applications such as implants.

ショット材はＺｒＯ２を含む。ジルコニア材は熱伝導性が低い為、合金表面近傍の相変態を起こし易い。ショット材におけるＺｒＯ２の含有量は、ショットピーニング工程で発生する熱エネルギーのショット材側への伝達を抑制する観点から、３０質量％以上であってもよく、６０質量％以上であってもよく、１００質量％（実質的にＺｒＯ２からなるもの）であってもよい。ショット材には、Ｆｅ、Ｃｒ、Ｓｉ、Ａｌ、Ｃｕ等を構成元素として含む化合物（例えば、Ａｌ２Ｏ３、ＳｉＯ２）を、ＺｒＯ２以外の成分として少量含んでいてもよい。 The shot material contains ZrO 2 . Since zirconia materials have low thermal conductivity, they are likely to undergo phase transformation near the alloy surface. The content of ZrO 2 in the shot material may be 30 mass% or more, or may be 60 mass% or more, from the viewpoint of suppressing the transfer of heat energy generated in the shot peening step to the shot material side. , 100 mass% (substantially consisting of ZrO 2 ). The shot material may contain a small amount of a compound containing Fe, Cr, Si, Al, Cu or the like as a constituent element (for example, Al 2 O 3 , SiO 2 ) as a component other than ZrO 2 .

ショット材の平均粒径は０．０５〜１．０ｍｍであってもよく、０．１〜０．７５ｍｍであってもよく、０．１〜０．５ｍｍであってもよく、０．１〜０．３ｍｍであってもよく、０．１〜０．１５ｍｍであってもよい。平均粒径が０．０５ｍｍ未満ではショット材が軽いため、Ｃｏ−Ｃｒ合金表面を充分に改質することが難しくなる傾向があり、一方、１．０ｍｍを超えると、所望のビジュアルカバレージ（目視によるショット材打痕の占有面積率）を達成するための時間が長くなって処理効率が悪くなる傾向がある。ここでの平均粒径は、ふるいを用いて測定される値である。 The average particle size of the shot material may be 0.05 to 1.0 mm, 0.1 to 0.75 mm, 0.1 to 0.5 mm, or 0.1 to 0.1 mm. It may be 0.3 mm or 0.1 to 0.15 mm. If the average particle size is less than 0.05 mm, the shot material is light, and it tends to be difficult to sufficiently modify the Co-Cr alloy surface. On the other hand, if it exceeds 1.0 mm, the desired visual coverage (visual The processing time tends to be poor because the time for achieving the shot material dent area (occupied area ratio) becomes long. The average particle diameter here is a value measured using a sieve.

ショット材のビッカース硬さ（ＨＶ）は５００〜１３００であってもよく、６００〜１２００であってもよく、７００〜１１００であってもよく、９００〜１１００であってもよい。ビッカース硬さが５００未満では充分な深さまで相変態を起こし難く、一方１２００超では表面粗さが大きくなり過ぎるため、き裂破壊が生じ易い傾向がある。 The Vickers hardness (HV) of the shot material may be 500 to 1300, 600 to 1200, 700 to 1100, or 900 to 1100. If the Vickers hardness is less than 500, phase transformation is unlikely to occur to a sufficient depth, while if it exceeds 1200, the surface roughness becomes too large, and thus crack fracture tends to occur.

ショット材の密度は１〜１０ｇ／ｃｍ３であってもよく、２．５〜７．５ｇ／ｃｍ３であってもよく、４〜６ｇ／ｃｍ３であってもよい。ショット材の密度が１ｇ／ｃｍ３未満では、インテンシティが弱く、充分な深さまで相変態を起こし難い傾向があり、一方１０ｇ／ｃｍ３超では、インテンシティが強く、表面粗さが大きくなり、き裂破壊が生じ易くなる傾向がある。 The density of the shot material may be 1 to 10 g/cm 3 , 2.5 to 7.5 g/cm 3 , or 4 to 6 g/cm 3 . The density of less than 1 g / cm 3 of shots, weak intensity tends to hardly undergo phase transformation to a sufficient depth, on the one hand, 10 g / cm 3 greater, strong intensity, the surface roughness becomes large, Crack fracture tends to occur easily.

ショットピーニング処理の方法としては、回転投射法、エアー吸引法、加圧ブラスト法等が挙げられる。これらのうち、複雑な装置の構築が不要であるという観点から、エアー吸引法を用いることができる。エアー吸引法は、ＺｒＯ２を含むショット材自体が破壊されてしまうことを抑制し易いという利点もある。 Examples of the shot peening method include a rotary projection method, an air suction method, and a pressure blast method. Among these, the air suction method can be used from the viewpoint that it is not necessary to construct a complicated device. The air suction method also has an advantage that it is easy to prevent the shot material containing ZrO 2 from being destroyed.

噴射圧力は適宜設定すればよいが、例えば０．１〜０．５ＭＰａ程度とすることができる。なお、噴射圧力が０．１ＭＰａ未満ではショット材が噴出し難い傾向があり、一方、０．５ＭＰａを超えたとしても改質後の硬度がサチュレートする傾向がある。 The injection pressure may be set appropriately, but may be, for example, about 0.1 to 0.5 MPa. It should be noted that if the injection pressure is less than 0.1 MPa, the shot material tends to be less likely to be ejected, while if it exceeds 0.5 MPa, the hardness after modification tends to saturate.

噴射時間は所望のカバレージが達成されるように適宜設定することができる。カバレージは少なくとも２００％以上であってもよく、５００％以上であってもよく、７５０％以上であってもよく、９００％以上であってもよい。カバレージの上限は、Ｃｏ−Ｃｒ合金の表面近傍の相変態を充分に進行させるという観点から、１０００％とすることができる。なお、ショット材を表面に打ち始めてから、全ての領域が打痕によって覆われた状態をカバレージ１００％と言う。例えば、カバレージ２００％とは、カバレージ１００％の状態から、さらにカバレージを０％から１００％にするまでに要した時間だけショットを行うことを意味する。 The injection time can be set appropriately so that the desired coverage is achieved. The coverage may be at least 200% or more, 500% or more, 750% or more, and 900% or more. The upper limit of the coverage can be set to 1000% from the viewpoint of sufficiently promoting the phase transformation near the surface of the Co-Cr alloy. In addition, the state in which all areas are covered with dents after the shot material is started to hit the surface is called 100% coverage. For example, a coverage of 200% means that a shot is performed only for the time required to change the coverage from 0% to 100% from the state of 100% coverage.

ショットピーニング処理後のＣｏ−Ｃｒ合金の表面粗さ（Ｒｚ）は、１０μｍ未満であってもよく、５μｍ未満であってもよい。例えば人工関節等でのＣｏ−Ｃｒ合金の使用を想定した場合、摺動面における摩耗粉の発生を抑制する目的から、後述のとおりショットピーニング処理後に研磨工程が実施される。ショットピーニング処理後の表面粗さが１０μｍ以上であると、鏡面を達成するまでに研磨量が多くなってしまう。このことは、プロセス上非効率であるばかりでなく、ショットピーニング処理により改質された層を余計に除去することとなる。 The surface roughness (Rz) of the Co—Cr alloy after the shot peening treatment may be less than 10 μm or less than 5 μm. For example, assuming the use of a Co—Cr alloy in an artificial joint or the like, a polishing step is performed after the shot peening treatment as described below, for the purpose of suppressing the generation of abrasion powder on the sliding surface. When the surface roughness after the shot peening treatment is 10 μm or more, the polishing amount increases until the mirror surface is achieved. This is not only inefficient in the process, but also removes extra layers modified by the shot peening process.

ショットピーニング処理の各種条件（ショット材の種類、ショット材の噴射圧力、カバレージ量等）を変更することによって、合金の表面粗さ、合金表面近傍の相変態の量を調整することができる。これにより合金の引張強度、硬さ等を調整することができるため、合金に対して所望の機械的特性を与えることができる。 The surface roughness of the alloy and the amount of phase transformation near the alloy surface can be adjusted by changing various conditions of the shot peening treatment (type of shot material, injection pressure of shot material, coverage amount, etc.). This makes it possible to adjust the tensile strength, hardness, etc. of the alloy, so that desired mechanical properties can be given to the alloy.

なお、ショットピーニング処理により合金表面が改質されたこと（高強度の相が表面に導入されたこと）は、簡便には合金表面のビッカース硬さ（ＨＶ）を測定することで判断することができる。 The fact that the alloy surface has been modified by the shot peening treatment (the high-strength phase has been introduced into the surface) can be judged simply by measuring the Vickers hardness (HV) of the alloy surface. it can.

［高疲労強度Ｃｏ−Ｃｒ合金の製造方法］
本実施形態の高疲労強度Ｃｏ−Ｃｒ合金の製造方法は、Ｃｏ−Ｃｒ合金に対し、ＺｒＯ２を含むショット材を用いてショットピーニング処理する工程を備える。各種材料、ショットピーニング処理する工程に関する各種条件等は、Ｃｏ−Ｃｒ合金の表面改質方法の内容に準拠する。 [Method for producing high fatigue strength Co-Cr alloy]
The method for manufacturing a high fatigue strength Co—Cr alloy of the present embodiment includes a step of subjecting a Co—Cr alloy to a shot peening treatment using a shot material containing ZrO 2 . Various materials, various conditions regarding the step of performing the shot peening treatment, and the like are based on the content of the surface modification method of the Co—Cr alloy.

本実施形態の製造方法は、ショットピーニング処理する工程の後に、さらに研磨工程を備えていてもよい。すなわち、ショットピーニング処理されたＣｏ−Ｃｒ合金表面をさらに研磨してもよい。研磨工程は、例えば機械研磨、電解研磨、化学研磨等により実施することができる。 The manufacturing method of the present embodiment may further include a polishing step after the step of performing the shot peening process. That is, the Co—Cr alloy surface that has been shot peened may be further polished. The polishing step can be performed by, for example, mechanical polishing, electrolytic polishing, chemical polishing, or the like.

［高疲労強度Ｃｏ−Ｃｒ合金］
本実施形態の高疲労強度Ｃｏ−Ｃｒ合金は、内部から表面にかけてε−ｈｃｐ相が漸増しかつγ−ｆｃｃ相が漸減する合金である。このような特徴的な材料（傾斜材料）は、表面近傍のみを選択的に相変態させることが可能なショットピーニング処理により導入することができる。すなわち、本実施形態の高疲労強度Ｃｏ−Ｃｒ合金は、（好ましくはＺｒＯ２を含むショット材を用いて）ショットピーニング処理されてなるＣｏ−Ｃｒ合金であるということができる。なお、よりマクロ的に表現すると、本実施形態の高疲労強度Ｃｏ−Ｃｒ合金は、実質的にγ−ｆｃｃ相からなる内層と、ε−ｈｃｐ相を有する外層と、を備える合金であるということもできる。 [High fatigue strength Co-Cr alloy]
The high fatigue strength Co—Cr alloy of the present embodiment is an alloy in which the ε-hcp phase gradually increases and the γ-fcc phase gradually decreases from the inside to the surface. Such a characteristic material (gradient material) can be introduced by a shot peening treatment capable of selectively performing phase transformation only in the vicinity of the surface. That is, it can be said that the high fatigue strength Co—Cr alloy of the present embodiment is a Co—Cr alloy that is shot peened (preferably using a shot material containing ZrO 2 ). When expressed in a more macroscopic manner, the high fatigue strength Co—Cr alloy of the present embodiment is an alloy that includes an inner layer that substantially consists of a γ-fcc phase and an outer layer that has an ε-hcp phase. You can also

本実施形態の高疲労強度Ｃｏ−Ｃｒ合金の表面のビッカース硬さ（ＨＶ）は５００以上であってもよく、５５０以上であってもよく、６００以上であってもよい。ショットピーニング処理前のＣｏ−Ｃｒ合金の表面のビッカース硬さが４００程度であることに鑑みると、大幅に表面強度が向上している。 The Vickers hardness (HV) of the surface of the high fatigue strength Co—Cr alloy of the present embodiment may be 500 or more, 550 or more, and 600 or more. Considering that the Vickers hardness of the surface of the Co—Cr alloy before the shot peening treatment is about 400, the surface strength is significantly improved.

ショットピーニング処理の影響は合金表面から一定深さまで達する。処理条件にも依存するため一概には言えないが、例えば表面から４００μｍ未満の、あるいは３５０μｍ未満の、あるいは３００μｍ未満の領域において、未処理の場合に比して合金のビッカース硬さが向上している。これは、この程度の深さまでγ−ｆｃｃ相（既存の靭性を有する相）からε−ｈｃｐ相（高い強度を有する相）への相変態が生じているためであると考えられる。すなわち、本実施形態の高疲労強度Ｃｏ−Ｃｒ合金においては、γ−ｆｃｃ相からなる内層上に、ε−ｈｃｐ相を有する外層が４００μｍ未満の厚さで形成されているということができる。 The effect of shot peening treatment reaches a certain depth from the alloy surface. Although it cannot be generally stated because it depends on the treatment condition, for example, in the region of less than 400 μm, less than 350 μm, or less than 300 μm from the surface, the Vickers hardness of the alloy is improved as compared with the untreated case. There is. It is considered that this is because the phase transformation from the γ-fcc phase (phase having existing toughness) to the ε-hcp phase (phase having high strength) occurs up to this depth. That is, it can be said that in the high fatigue strength Co—Cr alloy of the present embodiment, the outer layer having the ε-hcp phase is formed with a thickness of less than 400 μm on the inner layer made of the γ-fcc phase.

ＸＲＤ回折法による解析により、形成されたε−ｈｃｐ相の割合（体積割合）を定量的に算出することができる。また、ＥＢＳＤ法による解析により、内部方向を考慮したε−ｈｃｐ相の割合を評価することができる。高疲労強度Ｃｏ−Ｃｒ合金において、表面近傍（表面からの深さ１５μｍ程度）でのε−ｈｃｐ相の割合は３０％以上であってもよく、３５％以上であってもよく、４０％以上であってもよい。ＺｒＯ２を含むショット材を用いることで、ε−ｈｃｐ相の割合を４０％以上にし易くなる。なお、残部は実質的にγ−ｆｃｃ相である。ショットピーニング処理前のε−ｈｃｐ相の割合が概ね０％程度であることに鑑みると、相当量のε−ｈｃｐ相が導入されている。なお、カバレージを上げることでε−ｈｃｐ相の割合をさらに上げることも可能である。 The ratio (volume ratio) of the formed ε-hcp phase can be quantitatively calculated by the analysis by the XRD diffraction method. Moreover, the ratio of the ε-hcp phase considering the internal direction can be evaluated by the analysis by the EBSD method. In the high fatigue strength Co—Cr alloy, the ratio of the ε-hcp phase near the surface (depth from the surface is about 15 μm) may be 30% or more, 35% or more, 40% or more. May be By using the shot material containing ZrO 2 , it becomes easy to make the ratio of the ε-hcp phase 40% or more. The balance is substantially the γ-fcc phase. Considering that the ratio of the ε-hcp phase before the shot peening treatment is about 0%, a considerable amount of the ε-hcp phase is introduced. It is also possible to further increase the ratio of the ε-hcp phase by increasing the coverage.

ショットピーニング処理により合金表面近傍の結晶粒は微細化される。高疲労強度Ｃｏ−Ｃｒ合金において、結晶粒の平均サイズは３μｍ未満であってもよく、２μｍ未満であってもよく、１．５μｍ未満であってもよく、１μｍ未満であってもよい。ショットピーニング処理前の結晶粒の平均サイズが６μｍ程度であることに鑑みると、大幅に結晶粒が微細化している。 Crystal grains near the surface of the alloy are refined by the shot peening treatment. In the high fatigue strength Co—Cr alloy, the average size of the crystal grains may be less than 3 μm, less than 2 μm, less than 1.5 μm, or less than 1 μm. Considering that the average size of the crystal grains before the shot peening treatment is about 6 μm, the crystal grains are significantly miniaturized.

Ｃｏ−Ｃｒ合金におけるγ−ｆｃｃ相及びε−ｈｃｐ相の存在態様、及び微細化された結晶粒の存在態様については、例えばＥＢＳＤ（Ｅｌｅｃｔｒｏｎ Ｂａｃｋ Ｓｃａｔｔｅｒ Ｄｉｆｆｒａｃｔｉｏｎ Ｐａｔｔｅｒｎｓ：電子後方散乱回折）法により観察することができる。 Regarding the existence mode of the γ-fcc phase and the ε-hcp phase in the Co—Cr alloy and the existence mode of the refined crystal grains, for example, to observe by an EBSD (Electron Back Scatter Diffraction Patterns: Electron Backscatter Diffraction) method. You can

本実施形態の高疲労強度Ｃｏ−Ｃｒ合金はインプラント材料として好適であり、また表面粗さや硬さを調整することができるため、摺動部や脊髄用ピン等幅広く使用することができる。 The high fatigue strength Co—Cr alloy of the present embodiment is suitable as an implant material and can adjust the surface roughness and hardness, so that it can be widely used for sliding parts, spinal cord pins and the like.

以下、実施例を挙げて本開示についてさらに具体的に説明する。ただし、本開示はこれら実施例に限定されるものではない。 Hereinafter, the present disclosure will be described more specifically with reference to Examples. However, the present disclosure is not limited to these examples.

（実験１：ショット材の材質による比較）
供試材として、医療用Ｃｏ−２８Ｃｒ−６Ｍｏ合金（ＡＳＴＭ Ｆ１５３７）を用いた。表１に合金組成（単位：質量％）を示す。ショットピーニング処理に際し、処理面を予めＡｌ２Ｏ３粉末で研磨して用いた。 (Experiment 1: Comparison of shot materials)
A medical Co-28Cr-6Mo alloy (ASTM F1537) was used as a test material. Table 1 shows the alloy composition (unit: mass %). In the shot peening treatment, the treated surface was used after being polished with Al 2 O 3 powder in advance.

表２に示すショットピーニング条件にて、ノズル径６ｍｍ、噴射距離１００ｍｍ、カバレージ３００％として、供試材に対しショットピーニング処理した。ショットピーニング処理にはエアー吸引法の装置を用いた。 Under the shot peening conditions shown in Table 2, shot peening treatment was performed on the test material with a nozzle diameter of 6 mm, an injection distance of 100 mm, and a coverage of 300%. An air suction device was used for the shot peening treatment.

ショットピーニング処理前後の供試材の表面粗さＲｚを、接触式表面粗さ測定器を用いて測定した。測定結果を図１に示す。図中、ＮＰとは、ショットピーニング処理を行わない未処理（Ａｌ２Ｏ３研磨を施したのみ）の供試材のデータである。 The surface roughness Rz of the test material before and after the shot peening treatment was measured using a contact surface roughness measuring device. The measurement result is shown in FIG. In the figure, NP is data of an untreated sample material (only Al 2 O 3 polishing was performed) without shot peening treatment.

ショットピーニング処理前後の供試材について、Ｘ線回折装置を用いてＸＲＤ回折法により解析を行った。ショットピーニング処理前後の供試材のＸＲＤ回折結果を図２に示す。ＸＲＤチャートの主要ピークから、下記式を用いてε相の割合を算出した。下記式中、Ｖは体積分率を表し、Ｉはピークの積分強度を表す。
The sample material before and after the shot peening treatment was analyzed by the XRD diffraction method using an X-ray diffractometer. The XRD diffraction results of the test material before and after the shot peening treatment are shown in FIG. From the main peaks of the XRD chart, the ratio of ε phase was calculated using the following formula. In the following formula, V represents a volume fraction and I represents a peak integrated intensity.

図３に、上記にて算出された、ショットピーニング処理後の供試材におけるε相の割合（体積割合）を示す。同図より、最もε相への変態割合が大きいショット材はＧＢ−Ｋであることが分かる。ここから、粒径が小さいショット材は投射面に衝突する頻度が高く、結果として大きなひずみが形成されたものと考えられる。また、ＳＢＭ４４ＴとＺＢ１２０とを比較すると、硬度の高いＺＢ１２０の方がε相の割合が大きいことが分かる。ここから、ショット材の硬度が高いほど衝突エネルギーが大きいものと考えられる。以上より、加工誘起マルテンサイト変態を促進させるためには、小粒径かつ高硬度のショット材が好適であると考えられる。 FIG. 3 shows the ratio (volume ratio) of the ε phase in the test material after the shot peening treatment, calculated as described above. From the figure, it is understood that the shot material having the highest transformation ratio to the ε phase is GB-K. From this, it is considered that the shot material having a small particle diameter frequently collides with the projection surface, and as a result, a large strain is formed. Further, comparing SBM44T and ZB120, it is found that ZB120 having a higher hardness has a larger proportion of ε phase. From this, it is considered that the higher the hardness of the shot material, the greater the collision energy. From the above, it is considered that a shot material having a small grain size and high hardness is suitable for promoting the work-induced martensitic transformation.

次に、ショットピーニング処理前後の供試材について、電界放出型走査電子顕微鏡を用いてＥＢＳＤ法による解析を行った。図４に、ショットピーニング処理前後の供試材のＥＢＳＤ観察結果を示す。図４の上図は供試材表面近傍のγ相及びε相の存在態様を示し、下図は供試材表面近傍の結晶粒の様子を示す。上図中のε相割合は観察画像から解析ソフトにて求めたものである。また、下図中のＧＳは平均粒径（Ｇｒａｉｎ Ｓｉｚｅ）を意味する。観察画像から解析ソフトにてバンドコントラストを出した後、粒界線を引き、線に囲まれた部分を一粒界とし、取得結晶の平均粒径を算出した。ＥＢＳＤによる観察の結果、ショットピーニング処理によりε相が導入されたこと、及び表面近傍の結晶粒が微細化されたことが分かった。ε相への変態量が最大であったＧＢ−Ｋ（図３参照）については、主に表面近傍でε相への相変態が生じ、内部は未変態のγ相が多く存在していた。ここから、ショット材の硬度が高いほど衝突エネルギーは大きく、結果として内部まで加工誘起マルテンサイト変態が生じたと考えられる。 Next, the sample material before and after the shot peening treatment was analyzed by the EBSD method using a field emission scanning electron microscope. FIG. 4 shows the EBSD observation results of the test material before and after the shot peening treatment. The upper diagram of FIG. 4 shows the existence states of the γ phase and the ε phase near the surface of the test material, and the lower diagram shows the state of crystal grains near the surface of the test material. The ε phase ratio in the above figure was obtained from the observed image using analysis software. Further, GS in the figure below means the average particle size (Grain Size). After the band contrast was obtained from the observed image with analysis software, a grain boundary line was drawn, and the portion surrounded by the line was defined as one grain boundary, and the average grain size of the obtained crystals was calculated. As a result of observation by EBSD, it was found that the ε phase was introduced by the shot peening treatment and that the crystal grains near the surface were refined. Regarding GB-K (see FIG. 3), which had the largest amount of transformation to the ε phase, phase transformation to the ε phase occurred mainly in the vicinity of the surface, and a large amount of untransformed γ phase was present inside. From this, it is considered that the higher the hardness of the shot material is, the larger the collision energy is, and as a result, the processing-induced martensitic transformation is generated inside.

図５に、ショットピーニング処理前後の供試材のビッカース硬さ（ＨＶ）を示す。 FIG. 5 shows the Vickers hardness (HV) of the test material before and after the shot peening treatment.

（実験２：ジルコニアショット材の種類による比較）
ショットピーニング条件を表３に示すように変更したこと以外は、実験１と同様にして供試材に対してショットピーニング処理を行った。ショット材Ａ〜ＥはいずれもＺｒＯ２を主成分として含むものである。表中、ショット材Ａ、Ｃ、Ｄ及びＥはサンゴバン社製、ショット材Ｂは東ソー株式会社製である。 (Experiment 2: Comparison by type of zirconia shot material)
A shot peening treatment was performed on the test material in the same manner as in Experiment 1 except that the shot peening conditions were changed as shown in Table 3. Each of the shot materials A to E contains ZrO 2 as a main component. In the table, shot materials A, C, D and E are manufactured by Saint-Gobain, and shot material B is manufactured by Tosoh Corporation.

実験１と同様にして、各条件でのショットピーニング処理後のε相の割合をＥＢＳＤの観察結果から算出した。結果を表４に示す。 In the same manner as in Experiment 1, the ratio of the ε phase after the shot peening treatment under each condition was calculated from the observation result of EBSD. The results are shown in Table 4.

実施例によれば、Ｃｏ−Ｃｒ合金の表面近傍を選択的にε相に相変態（加工誘起マルテンサイト変態）させることで傾斜材料とし、これにより表面近傍が高強度でありながら内部の靭性が維持されている材料を得ることができた。すなわち、外部からの負荷に対する強さを有し、かつ柔軟性をも有している、疲労強度に優れる（高疲労強度）材料を得ることができた。 According to the examples, the vicinity of the surface of the Co—Cr alloy is selectively transformed into the ε phase by phase transformation (work-induced martensite transformation) to obtain a graded material, which results in high strength in the vicinity of the surface and internal toughness. It was possible to obtain a material that was maintained. That is, it was possible to obtain a material having high fatigue strength (high fatigue strength), which has strength against external load and also has flexibility.

Claims (6)

Ｃｏ−Ｃｒ合金に対し、ＺｒＯ２を含むショット材を用いてショットピーニング処理する工程を備える、Ｃｏ−Ｃｒ合金の表面改質方法。 To Co-Cr alloy, comprising the step of shot peening using a shot material comprising ZrO 2, the surface modification method of the Co-Cr alloy. 前記ショット材の平均粒径が０．０５〜１．０ｍｍである、請求項１に記載の表面改質方法。 The surface modification method according to claim 1, wherein the shot material has an average particle diameter of 0.05 to 1.0 mm. Ｃｏ−Ｃｒ合金に対し、ＺｒＯ２を含むショット材を用いてショットピーニング処理する工程を備える、高疲労強度Ｃｏ−Ｃｒ合金の製造方法。 A method for producing a high fatigue strength Co-Cr alloy, which comprises a step of subjecting a Co-Cr alloy to a shot peening treatment using a shot material containing ZrO 2 . 前記ショット材の平均粒径が０．０５〜１．０ｍｍである、請求項３に記載の製造方法。 The manufacturing method according to claim 3, wherein the shot material has an average particle diameter of 0.05 to 1.0 mm. 内部から表面にかけてε−ｈｃｐ相が漸増しかつγ−ｆｃｃ相が漸減する、高疲労強度Ｃｏ−Ｃｒ合金。 A high fatigue strength Co-Cr alloy in which the ε-hcp phase gradually increases and the γ-fcc phase gradually decreases from the inside to the surface. 表面のビッカース硬さ（ＨＶ）が５００以上である、請求項５に記載のＣｏ−Ｃｒ合金。 The Co-Cr alloy according to claim 5, wherein the surface has a Vickers hardness (HV) of 500 or more.
JP2018233570A 2018-12-13 2018-12-13 METHOD FOR MODIFYING SURFACE OF Co-Cr ALLOY, METHOD OF MANUFACTURING HIGH FATIGUE STRENGTH Co-Cr ALLOY, AND HIGH FATIGUE STRENGTH Co-Cr ALLOY Pending JP2020093352A (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06312373A (en) * 1993-04-27 1994-11-08 Kyocera Corp Shot member
JP2007502372A (en) * 2003-05-23 2007-02-08 エイティーアイ・プロパティーズ・インコーポレーテッド Cobalt alloy, method for producing cobalt alloy, and implant and product manufactured therefrom
JP2008264988A (en) * 2007-03-28 2008-11-06 Kyocera Corp Manufacturing method of cutting tool
JP2012066337A (en) * 2010-09-22 2012-04-05 Mitsubishi Materials Corp Cutting insert made of tungsten cemented carbide based super hard alloy, and method of manufacturing the same
JP2014237864A (en) * 2013-06-06 2014-12-18 Ｊｆｅエンジニアリング株式会社 Manufacturing method of coated member and coated member
US20150013412A1 (en) * 2011-07-14 2015-01-15 Sonats Sas Processes and Apparatus for Surface Modification
JP2017066526A (en) * 2015-09-30 2017-04-06 新日鉄住金化学株式会社 Method for manufacturing member having metal composite layer and member having aluminum nickel composite layer

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5409415A (en) * 1992-07-02 1995-04-25 Nikkato Corp. Shot method
US8475536B2 (en) * 2010-01-29 2013-07-02 DePuy Synthes Products, LLC Methods and devices for implants with improved cement adhesion

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06312373A (en) * 1993-04-27 1994-11-08 Kyocera Corp Shot member
JP2007502372A (en) * 2003-05-23 2007-02-08 エイティーアイ・プロパティーズ・インコーポレーテッド Cobalt alloy, method for producing cobalt alloy, and implant and product manufactured therefrom
JP2008264988A (en) * 2007-03-28 2008-11-06 Kyocera Corp Manufacturing method of cutting tool
JP2012066337A (en) * 2010-09-22 2012-04-05 Mitsubishi Materials Corp Cutting insert made of tungsten cemented carbide based super hard alloy, and method of manufacturing the same
US20150013412A1 (en) * 2011-07-14 2015-01-15 Sonats Sas Processes and Apparatus for Surface Modification
JP2014237864A (en) * 2013-06-06 2014-12-18 Ｊｆｅエンジニアリング株式会社 Manufacturing method of coated member and coated member
JP2017066526A (en) * 2015-09-30 2017-04-06 新日鉄住金化学株式会社 Method for manufacturing member having metal composite layer and member having aluminum nickel composite layer

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