JP2004232068A

JP2004232068A - Hard carbon film-formed body, and production method therefor

Info

Publication number: JP2004232068A
Application number: JP2003024946A
Authority: JP
Inventors: Eiji Iwamura; 栄治岩村
Original assignee: Japan Science and Technology Agency
Current assignee: Japan Science and Technology Agency
Priority date: 2003-01-31
Filing date: 2003-01-31
Publication date: 2004-08-19

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hard carbon film-formed body in which the adhesive strength in the boundary of a different kind of material between a base material and a carbon film and the strength of itself can be improved, and to provide a production method therefor. <P>SOLUTION: The hard carbon film-formed body consists of a surface layer 2 of a hard carbon film and an iron based base material 1 in contact with the surface layer 2. On the boundary between the surface layer 2 and the base material 1, an amorphous carbon film which is amorphous like a compound of silicon and addition elements included in the iron or iron based base material and contains 0.1 to 30 at% silicon is formed as the surface layer 2. Next, an electronic beam accelerated by ≤100 kV is irradiated. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車部品等に代表される摺動機械部品等で、特に、鉄系基材に対して低摩擦と優れた耐久性を有する硬質炭素被膜成形体およびその製造方法に関するものである。
【０００２】
【従来の技術】
従来技術の硬質炭素被膜成形体を大別すると、以下の３種類のものに分けられる。
【０００３】
（１）硬質炭素被膜成形体の膜応力を制御するもの（下記特許文献１及び２参照）
（２）硬質炭素被膜成形体の基材と炭素膜の間に中間層を設けるもの（下記特許文献３及び４参照）
（３）硬質炭素被膜成形体の基材の表面にイオン注入による混合層を形成するもの（下記特許文献５及び６参照）
【０００４】
【特許文献１】
特開平５−２０２４７７号公報
【０００５】
【特許文献２】
特開平１−２９４８６７号公報
【０００６】
【特許文献３】
特開２０００−１１９８４３号公報
【０００７】
【特許文献４】
特開平４−３３７０８５号公報
【０００８】
【特許文献５】
特開平７−２６８６０７号公報
【０００９】
【特許文献６】
特開平７−９０５５３号公報
【００１０】
【発明が解決しようとする課題】
しかしながら、上記（１）の先行技術の場合には、基本的に硬質炭素被膜成形体の基材と炭素膜との異種材料界面における密着不安定性が存在する。
【００１１】
また、上記（２）の先行技術は、多くの場合、硬質炭素被膜成形体の脆性的な化合物相を中間層内に包含することが多く、また中間層を傾斜組成化や非晶質化しても基材の最表面にはやはり異種材料界面が残り、荷重負荷が大きい使用環境等で密着不良の原因となる。
【００１２】
更に、上記（３）の先行技術の場合には、硬質炭素被膜成形体において、イオン注入により膜中に強い圧縮応力が生じるために、変形に対する感受性が増大し、密着不良の原因となりやすい。これは上記（２）の先行技術の中間層形成におけるイオン注入・照射においても同様なことが言える。
【００１３】
また、硬質炭素被膜成形体の基材最表面に被覆材との拡散層を形成することも考えられるが、成形体全体を加熱する必要があり、鉄系基材の場合、焼入れ・焼きなまし効果により強度の劣化・脆性化が生じ、耐久性が劣化し実用に適さなくなる。
【００１４】
本発明は、上記状況に鑑みて、硬質炭素被膜成形体の基材と炭素膜との異種材料界面における密着強度及び硬質炭素被膜成形体の強度の向上を図ることができる硬質炭素被膜成形体およびその製造方法を提供することを目的とする。
【００１５】
【課題を解決するための手段】
本発明は、上記目的を達成するために、
〔１〕硬質炭素被膜成形体において、硬質炭素膜の表面層と、この表面層に接する鉄系基材からなり、前記表面層と前記基材との界面は、シリコンと鉄もしくは、鉄系基材に含まれる添加元素との化合物状非晶質であり、前記表面層として、シリコンを０．１ａｔ％以上、３０ａｔ％以下を含むアモルファスカーボン膜からなり、１００ｋＶ以下に加速された電子線を照射してなる。
【００１６】
〔２〕硬質炭素被膜成形体において、硬質炭素膜の表面層と、この表面層が中間層を介して接する鉄系基材からなり、前記中間層と前記基材との界面は、シリコンと鉄もしくは、鉄系基材に含まれる添加元素との化合物状非晶質であり、前記中間層として、シリコンを０．１ａｔ％以上、３０ａｔ％以下を含むアモルファスカーボン膜からなり、１００ｋＶ以下に加速された電子線を照射してなる。
【００１７】
〔３〕硬質炭素被膜成形体の製造方法において、基材上に硬質炭素膜の表面層、もしくは硬質炭素膜の表面層及び中間層を形成し、この表面層もしくは中間層の形成後に、低エネルギー電子線照射を行い、低温にて特性を劣化することなく、密着性の高い拡散反応層を形成することを特徴とする。
【００１８】
〔４〕硬質炭素被膜成形体の製造方法において、硬質炭素膜の表面層と、この表面層に接する鉄系基材からなり、前記表面層と前記基材との界面には、シリコンと鉄もしくは、鉄系基材に含まれる添加元素との化合物状非晶質であり、前記表面層として、シリコンを０．１ａｔ％以上、３０ａｔ％以下を含むアモルファスカーボン膜を形成し、次いで、１００ｋＶ以下に加速された電子線を照射することを特徴とする。
【００１９】
〔５〕硬質炭素被膜成形体の製造方法において、硬質炭素膜の表面層と、この表面層が中間層を介して接する鉄系基材からなり、前記中間層と前記基材との界面には、シリコンと鉄もしくは、鉄系基材に含まれる添加元素との化合物状非晶質であり、前記中間層として、シリコンを０．１ａｔ％以上、３０ａｔ％以下を含むアモルファスカーボン膜を形成し、次いで、１００ｋＶ以下に加速された電子線を照射することを特徴とする。
【００２０】
〔６〕上記〔３〕、〔４〕又は〔５〕記載の硬質炭素被膜成形体の製造方法において、前記電子線の照射を大気中、もしくは減圧下の不活性ガス雰囲気中にて行うことを特徴とする。
【００２１】
【発明の実施の形態】
以下、本発明の実施の形態について詳細に説明する。
【００２２】
本発明は、基材と硬質炭素膜の界面に滑らかな拡散反応層が形成されており、硬質膜形成後に低エネルギー電子線を照射することで、その拡散反応層を形成し、低温にて特性を劣化させることなく密着性の高い硬質炭素膜を提供することを特徴とする。
【００２３】
〔実施例１〕
図１は本発明の実施例１の製造方法を示す図である。
【００２４】
まず、図１（ａ）に示すように、マグネトロンスパッタリングにてＳＵＪ２基材１上（３インチ径、厚さ５ｍｍ）に、シリコンを１０ａｔ％含む硬質炭素膜（ａ−Ｃ膜）２を１μｍ成膜した。スパッタリングターゲット３には市販の焼成グラファイトターゲットに、１ｃｍ角のシリコン基材をモザイク状に配置したものを用い、成膜ガスにはアルゴン＋１０％メタンガス４を用いて、プロセスガス圧３ｍｔｏｒｒとした。また、成膜中に基材１に対して、１００Ｖの直流バイアス電圧を印加した。なお、「ａｔ％」とは、原子数を基準とした百分率をいう。
【００２５】
次に、図１（ｂ）に示すように、電子線照射装置５〔ウシオ電機（株）製Ｍｉｎ−ＥＢｌａｂｏＳＴＭ−ｃｈａｍｂｅｒ〕にて、０．１ｔｏｒｒの窒素ガス雰囲気、加速電圧６０ｋＶ、管電流０．３ｍＡ、照射距離３０ｍｍの条件、もしくは大気中、加速電圧６０ｋＶ、管電流０．３ｍＡ、照射距離５ｍｍの条件下で、２時間の電子線照射を実施した。
【００２６】
〔実施例２〕
図２は本発明の実施例２の製造方法を示す図である。
【００２７】
まず、図２（ａ）に示すように、マグネトロンスパッタリングにてＳＵＳ３０４基材１１上（３インチ径、厚さ５ｍｍ）に、シリコンを１０％含む硬質炭素膜（ａ−Ｃ膜）１２を１μｍ成膜した。スパッタリングターゲット１３には市販の焼成グラファイトターゲットに、１ｃｍ角のシリコン基材をモザイク状に配置したものを用い、成膜ガス１４にはアルゴン＋１０％メタンガスを用いて、プロセスガス圧３ｍｔｏｒｒとした。また、成膜中に基材１１に対して、１００Ｖの直流バイアス電圧を印加した。
【００２８】
次いで、図２（ｂ）に示すように、図１（ｂ）と同様に、電子線照射装置１５〔ウシオ電機（株）製Ｍｉｎ−ＥＢｌａｂｏＳＴＭ−ｃｈａｍｂｅｒ〕にて、０．１ｔｏｒｒの窒素ガス雰囲気で、加速電圧６０ｋＶ、管電流０．３ｍＡ、照射距離３０ｍｍの条件、もしくは大気中、加速電圧６０ｋＶ、管電流０．３ｍＡ、照射距離５ｍｍの条件下で、２時間の電子線照射を実施した。
【００２９】
〔本発明の硬質炭素被膜成形体の評価〕
得られた硬質炭素被膜成形体について、その結果、ＬＥＶＥＴＥＳＴスクラッチ試験による密着強度評価、オージェ分光（ＡＥＳ）分析による組成分布評価、透過型電子顕微鏡（ＴＥＭ）による組織観察を行った。硬度はナノインデンターにて測定した。
【００３０】
〔比較例〕
上記特許文献３（特開２０００−１１９８４３号公報参照）に示されるものと同様な方法で、マグネトロンスパッタにて基材／Ｃｒ金属層／Ｃｒ−Ｃ傾斜組成非晶質中間層／硬質炭素膜を形成した。硬質炭素膜部分の形成方法は、本発明の上記の実施例と同様とした。
【００３１】
主な評価結果を表１に示す。
【００３２】
【表１】

【００３３】
すなわち、上記本発明の実施例１では密着強度は７５Ｎ、硬度は５９ＧＰａであり、上記本発明の実施例２では、密着強度は６９Ｎ、硬度は５７ＧＰａであるのに対して、比較例１（基材ＳＵＪ２：電子線照射なし）では密着強度は５５Ｎ、硬度は５７ＧＰａであり、比較例２（基材ＳＵＳ３０４：電子線照射なし）では、密着強度は４７Ｎ、硬度は６１ＧＰａである。
【００３４】
上記から明らかなように、本発明の実施例によれば、比較例に比して、密着強度及び硬度ともに向上させることができた。
【００３５】
ここで、以下の点は本発明の特に重要な技術的事項である。
【００３６】
（１）シリコンは、特に鉄族元素（鉄、コバルト、ニッケル）との間に化合物や拡散層を形成しやすい。
【００３７】
また、シリコンは硬質炭素膜中に含有させても硬度や摩擦係数に悪影響を与えない。
【００３８】
（２）低エネルギー電子線照射によるために、エネルギーのみを付与することができ、運動量を与えないために、打ち込み効果による圧縮応力の発生を防ぐことができる。
【００３９】
また、基材の表面近傍領域において照射エネルギーのすべてを失ってしまうので、基材全体は劣化を起こすほど加熱されることがなく、界面に拡散層を形成することができる。
【００４０】
（３）シリコン組成については、０．１ａｔ％以下では密着性の向上に有効な拡散層が形成できない。また、３０ａｔ％を超えると、脆性的な鉄系元素とのシリサイド化合物や、炭素化合物を膜中に形成し、密着性や耐久性を劣化させる。よって、シリコン組成は、０．１ａｔ％以上３０ａｔ％以下とし、より好ましくは、１ａｔ％から２０ａｔ％である。
【００４１】
（４）照射電圧については、１００ｋＶを超えると、照射による基材温度の上昇及び硬質炭素膜の変質が発生する。よって、照射電圧は１００ｋＶ以下とし、より好ましくは３０〜６０ｋＶである。
【００４２】
（５）大気中もしくは減圧下での不活性ガス雰囲気照射については、真空中でも可能であるが、冷却・作業効率、特殊な真空装置を必要としない点で、この雰囲気が好ましい。
【００４３】
（６）膜形成方法としては、ＰＶＤ（ＰｈｙｓｉｃａｌＶａｐｏｒＤｅｐｏｓｉｔｉｏｎ）、ＣＶＤ（ＣｈｅｍｉｃａｌＶａｐｏｒＤｅｐｏｓｉｔｉｏｎ）のいずれであってもよい。
【００４４】
（７）膜構造は、電子線照射前では、基材／硬質炭素膜、基材／シリコンを含む硬質炭素膜／硬質炭素膜である。
【００４５】
次に、硬質炭素膜の最表面層が中間層を介して鉄系の基材に形成される場合について説明する。
【００４６】
図３は本発明の実施例３の製造方法を示す図である。
【００４７】
ここでは、基材２１／第１の中間層２２／第２の傾斜組成中間層２３／硬質炭素膜２４なる積層構造を以下のプロセスで製造した。
【００４８】
（１）まず、図３（ａ）に示すように、マグネトロンスパッタリングにてＳＵＳ３０４基材２１上（３インチ径、厚さ５ｍｍ）に、まず、第１の中間層２２を高純度シリコンをスパッタリングターゲットとして、約１０ｎｍの厚さに形成する。ここでは、第１の中間層２２は、あまり厚くないほうがよい。つまり、のり付け層としてシリコンが界面に存在する程度でよい。
【００４９】
（２）次いで、図３（ｂ）に示すように、傾斜組成中間層２３をシリコンとグラファイトをスパッタリングターゲットとして同時にスパッタリング成膜した。ここでは、傾斜組成中間層２３の厚みは全体で２００ｎｍとした。このとき、各ターゲットのスパッタリング電力をシリコンの場合には滑らかに低下させ、グラファイトについては滑らかに増加させることで、中間層２３内のシリコン（１００％から１０％まで：次工程で形成する硬質炭素層に組成が適度に滑らかに連続するほうが望ましく０％までとなってもよい）とカーボンの組成（０％から９０％）を滑らかに傾斜させた。
【００５０】
（３）次いで、図３（ｃ）に示すように、その傾斜組成中間層２３上にシリコンを１０％含む硬質炭素膜（ａ−Ｃ膜）２４を１μｍ成膜した。成膜ガスにはアルゴン＋１０％メタンガスを用いて、プロセスガス圧３ｍｔｏｒｒとした。また、成膜中に基材２１に対して、１００Ｖの直流バイアス電圧を印加した（中間層にバイアス印加は必ずしも必須ではないが、印加したほうが望ましい）。
【００５１】
（４）最後に、図３（ｄ）に示すように、図１（ｂ）と同様に電子線照射装置２５〔ウシオ電機（株）製Ｍｉｎ−ＥＢｌａｂｏＳＴＭ−ｃｈａｍｂｅｒ〕によって、０．１ｔｏｒｒの窒素ガス雰囲気、加速電圧６０ｋＶ、管電流０．３ｍＡ、照射距離３０ｍｍの条件、もしくは大気中、加速電圧６０ｋＶ、管電流０．３ｍＡ、照射距離５ｍｍの条件下で、２時間の電子線照射を実施した。
【００５２】
なお、評価方法は上記した実施例１及び２と同様である。
【００５３】
その結果、密着強度は７６Ｎ、硬質炭素膜の硬度は５７ＧＰａであった。
【００５４】
なお、本発明は上記実施例に限定されるものではなく、本発明の趣旨に基づいて種々の変形が可能であり、これらを本発明の範囲から排除するものではない。
【００５５】
【発明の効果】
以上、詳細に説明したように、本発明によれば、硬質炭素被膜成形体の基材と炭素膜との異種材料界面における密着強度及び硬質炭素被膜成形体の強度の向上を図ることができる。
【図面の簡単な説明】
【図１】本発明の実施例１の製造方法を示す図である。
【図２】本発明の実施例２の製造方法を示す図である。
【図３】本発明の実施例３の製造方法を示す図である。
【符号の説明】
１ＳＵＪ２基材
２，１２硬質炭素膜（ａ−Ｃ膜）
３，１３スパッタリングターゲット
４，１４，２４成膜ガス（アルゴン＋１０％メタンガス）
５，１５，２５電子線照射装置
１１ＳＵＳ３０４基材
２１基材
２２第１の中間層
２３第２の傾斜組成中間層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sliding machine component represented by an automobile component and the like, and more particularly to a hard carbon film molded article having low friction and excellent durability with respect to an iron-based substrate, and a method for producing the same.
[0002]
[Prior art]
The hard carbon film molded products of the prior art are roughly classified into the following three types.
[0003]
(1) Controlling the film stress of a hard carbon film molded body (see Patent Documents 1 and 2 below)
(2) One in which an intermediate layer is provided between the substrate of the hard carbon film molded body and the carbon film (see Patent Documents 3 and 4 below)
(3) Forming a mixed layer by ion implantation on the surface of a substrate of a hard carbon film molded body (see Patent Documents 5 and 6 below)
[0004]
[Patent Document 1]
JP-A-5-202577
[Patent Document 2]
JP-A-1-294867
[Patent Document 3]
JP 2000-119843 A
[Patent Document 4]
JP-A-4-337085
[Patent Document 5]
JP-A-7-268607
[Patent Document 6]
JP-A-7-90553
[Problems to be solved by the invention]
However, in the case of the prior art (1), there is basically instability of adhesion at the interface between different materials between the base material of the hard carbon film molded product and the carbon film.
[0011]
In the prior art (2), the brittle compound phase of the hard carbon film molded article is often included in the intermediate layer, and the intermediate layer is formed into a graded composition or amorphous state. Also, an interface of a different kind of material remains on the outermost surface of the substrate, which causes poor adhesion in a use environment where a large load is applied.
[0012]
Further, in the case of the prior art (3), in the hard carbon film molded body, since strong compressive stress is generated in the film by ion implantation, the sensitivity to deformation is increased, which is likely to cause poor adhesion. The same can be said for the ion implantation and irradiation in the intermediate layer formation of the prior art (2).
[0013]
It is also conceivable to form a diffusion layer with a coating material on the outermost surface of the base material of the hard carbon film molded product, but it is necessary to heat the entire molded product, and in the case of an iron-based substrate, due to the quenching / annealing effect, Deterioration of strength and embrittlement occur, resulting in deterioration of durability and rendering it unsuitable for practical use.
[0014]
The present invention has been made in view of the above-described circumstances, and a hard carbon film molded body capable of improving the adhesion strength and the strength of the hard carbon film molded body at a heterogeneous material interface between the substrate of the hard carbon film molded body and the carbon film, and It is an object of the present invention to provide a manufacturing method thereof.
[0015]
[Means for Solving the Problems]
The present invention, in order to achieve the above object,
[1] In the hard carbon film molded body, a surface layer of the hard carbon film and an iron-based substrate in contact with the surface layer are provided, and an interface between the surface layer and the substrate is formed of silicon and iron or an iron-based substrate. An amorphous carbon film containing 0.1 at% or more and 30 at% or less of silicon as the surface layer, and irradiated with an electron beam accelerated to 100 kV or less as the surface layer. Do it.
[0016]
[2] In the hard carbon film molded body, a surface layer of the hard carbon film and an iron-based substrate in which the surface layer is in contact with an intermediate layer interposed therebetween, and an interface between the intermediate layer and the substrate is formed of silicon and iron. Alternatively, the intermediate layer is an amorphous carbon film containing 0.1 at% or more and 30 at% or less of silicon as the intermediate layer, and is accelerated to 100 kV or less. Irradiated with an electron beam.
[0017]
[3] In the method for producing a hard carbon film molded product, a surface layer of a hard carbon film, or a surface layer and an intermediate layer of a hard carbon film are formed on a substrate, and after forming the surface layer or the intermediate layer, low energy is applied. It is characterized by performing electron beam irradiation to form a diffusion reaction layer having high adhesion without deteriorating characteristics at a low temperature.
[0018]
[4] In the method for producing a hard carbon film molded body, the hard carbon film comprises a surface layer and an iron-based substrate in contact with the surface layer, and an interface between the surface layer and the substrate includes silicon and iron or Forming an amorphous carbon film containing 0.1 at% or more and 30 at% or less of silicon as the surface layer, which is a compound amorphous with an additive element contained in the iron-based base material, Irradiated with accelerated electron beams.
[0019]
[5] In the method for producing a hard carbon film molded body, the surface layer of the hard carbon film and an iron-based substrate in which the surface layer is in contact with an intermediate layer interposed therebetween, and an interface between the intermediate layer and the substrate is Forming an amorphous carbon film containing silicon and iron or an additive element contained in an iron-based base material and containing 0.1 at% or more and 30 at% or less of silicon as the intermediate layer; Next, an electron beam accelerated to 100 kV or less is irradiated.
[0020]
[6] The method for producing a hard carbon film molded body according to the above [3], [4] or [5], wherein the irradiation with the electron beam is performed in the air or in an inert gas atmosphere under reduced pressure. Features.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0022]
In the present invention, a smooth diffusion reaction layer is formed at the interface between the base material and the hard carbon film, and by irradiating a low-energy electron beam after the formation of the hard film, the diffusion reaction layer is formed, and the characteristic is formed at a low temperature. Characterized by providing a hard carbon film having high adhesion without deteriorating the hardness.
[0023]
[Example 1]
FIG. 1 is a diagram illustrating a manufacturing method according to a first embodiment of the present invention.
[0024]
First, as shown in FIG. 1A, a hard carbon film (a-C film) 2 containing 10 at% of silicon was formed on a SUJ2 substrate 1 (3 inches in diameter and 5 mm in thickness) by 1 μm by magnetron sputtering. Filmed. As the sputtering target 3, a commercially available calcined graphite target obtained by arranging a silicon substrate of 1 cm square in a mosaic shape was used, and a film forming gas of argon + 10% methane gas 4 was used at a process gas pressure of 3 mtorr. Further, a DC bias voltage of 100 V was applied to the substrate 1 during the film formation. Note that “at%” refers to a percentage based on the number of atoms.
[0025]
Next, as shown in FIG. 1B, a nitrogen gas atmosphere of 0.1 torr, an accelerating voltage of 60 kV, and a tube current of an electron beam irradiator 5 [Min-EB labo STM-chamber manufactured by Ushio Inc.] were used. Electron beam irradiation was performed for 2 hours under the conditions of 0.3 mA and an irradiation distance of 30 mm, or under the conditions of an acceleration voltage of 60 kV, a tube current of 0.3 mA and an irradiation distance of 5 mm in the atmosphere.
[0026]
[Example 2]
FIG. 2 is a diagram illustrating a manufacturing method according to a second embodiment of the present invention.
[0027]
First, as shown in FIG. 2A, a hard carbon film (a-C film) 12 containing 10% silicon is formed on a SUS304 substrate 11 (3 inches in diameter and 5 mm in thickness) by 1 μm by magnetron sputtering. Filmed. As the sputtering target 13, a commercially available calcined graphite target having a silicon substrate of 1 cm square arranged in a mosaic shape was used. As the film forming gas 14, argon + 10% methane gas was used, and the process gas pressure was set at 3 mtorr. During the film formation, a DC bias voltage of 100 V was applied to the substrate 11.
[0028]
Next, as shown in FIG. 2 (b), similarly to FIG. 1 (b), nitrogen gas of 0.1 torr was applied by an electron beam irradiation device 15 [Min-EB labo STM-chamber manufactured by Ushio Inc.]. In an atmosphere, the electron beam irradiation was performed for 2 hours under the conditions of an acceleration voltage of 60 kV, a tube current of 0.3 mA, and an irradiation distance of 30 mm, or in the atmosphere of an acceleration voltage of 60 kV, a tube current of 0.3 mA, and an irradiation distance of 5 mm. .
[0029]
(Evaluation of the hard carbon film molded body of the present invention)
As a result, the obtained hard carbon film molded body was subjected to evaluation of adhesion strength by a LEVESTEST scratch test, evaluation of composition distribution by Auger spectroscopy (AES) analysis, and structure observation by a transmission electron microscope (TEM). Hardness was measured with a nano indenter.
[0030]
(Comparative example)
In the same manner as described in Patent Document 3 (see Japanese Patent Application Laid-Open No. 2000-119843), a substrate / Cr metal layer / Cr-C graded composition amorphous intermediate layer / hard carbon film is formed by magnetron sputtering. Formed. The method of forming the hard carbon film portion was the same as in the above-described embodiment of the present invention.
[0031]
Table 1 shows the main evaluation results.
[0032]
[Table 1]

[0033]
That is, in Example 1 of the present invention, the adhesive strength was 75 N and the hardness was 59 GPa. In Example 2 of the present invention, the adhesive strength was 69 N and the hardness was 57 GPa. The material SUJ2: without electron beam irradiation) has an adhesion strength of 55 N and a hardness of 57 GPa, and the comparative example 2 (base material SUS304: no electron beam irradiation) has an adhesion strength of 47 N and a hardness of 61 GPa.
[0034]
As is clear from the above, according to the example of the present invention, both the adhesion strength and the hardness could be improved as compared with the comparative example.
[0035]
Here, the following points are particularly important technical matters of the present invention.
[0036]
(1) Silicon easily forms a compound or a diffusion layer particularly with an iron group element (iron, cobalt, nickel).
[0037]
Even if silicon is contained in the hard carbon film, it does not adversely affect the hardness or the coefficient of friction.
[0038]
(2) Only energy can be applied because of low-energy electron beam irradiation, and generation of compressive stress due to the driving effect can be prevented because no momentum is applied.
[0039]
In addition, since all of the irradiation energy is lost in the region near the surface of the base material, the entire base material is not heated so much as to cause deterioration, and a diffusion layer can be formed at the interface.
[0040]
(3) If the silicon composition is less than 0.1 at%, a diffusion layer effective for improving the adhesion cannot be formed. On the other hand, when the content exceeds 30 at%, a brittle silicide compound with an iron-based element or a carbon compound is formed in the film, thereby deteriorating adhesion and durability. Therefore, the silicon composition is 0.1 at% or more and 30 at% or less, and more preferably 1 at% to 20 at%.
[0041]
(4) Regarding the irradiation voltage, if the irradiation voltage exceeds 100 kV, the temperature of the substrate increases due to the irradiation and the hard carbon film deteriorates. Therefore, the irradiation voltage is set to 100 kV or less, and more preferably 30 to 60 kV.
[0042]
(5) Irradiation with an inert gas atmosphere in the atmosphere or under reduced pressure is possible even in a vacuum, but this atmosphere is preferable in that cooling / working efficiency and special vacuum equipment are not required.
[0043]
(6) As a film formation method, any of PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition) may be used.
[0044]
(7) The film structure is: substrate / hard carbon film, substrate / hard carbon film containing silicon / hard carbon film before electron beam irradiation.
[0045]
Next, a case where the outermost surface layer of the hard carbon film is formed on an iron-based substrate via an intermediate layer will be described.
[0046]
FIG. 3 is a diagram showing a manufacturing method according to a third embodiment of the present invention.
[0047]
Here, a laminated structure of the substrate 21 / first intermediate layer 22 / second graded composition intermediate layer 23 / hard carbon film 24 was manufactured by the following process.
[0048]
(1) First, as shown in FIG. 3A, a first intermediate layer 22 is first formed of a high-purity silicon sputtering target on a SUS304 substrate 21 (3 inches in diameter and 5 mm in thickness) by magnetron sputtering. To a thickness of about 10 nm. Here, the first intermediate layer 22 should not be too thick. That is, it is sufficient that silicon is present at the interface as a gluing layer.
[0049]
(2) Next, as shown in FIG. 3B, the gradient composition intermediate layer 23 was formed by sputtering simultaneously using silicon and graphite as a sputtering target. Here, the thickness of the gradient composition intermediate layer 23 was set to 200 nm as a whole. At this time, the sputtering power of each target is smoothly reduced in the case of silicon and is smoothly increased in the case of graphite, so that silicon (from 100% to 10%: hard carbon formed in the next step) in the intermediate layer 23 is formed. It is desirable that the composition of the layer continues moderately smoothly, and the composition may be up to 0%) and the composition of carbon (0% to 90%) is smoothly inclined.
[0050]
(3) Next, as shown in FIG. 3C, a hard carbon film (a-C film) 24 containing 10% silicon was formed on the gradient composition intermediate layer 23 to a thickness of 1 μm. The process gas pressure was set to 3 mtorr using argon + 10% methane gas as a film forming gas. During the film formation, a DC bias voltage of 100 V was applied to the substrate 21 (the bias application to the intermediate layer is not essential, but is preferably applied).
[0051]
(4) Finally, as shown in FIG. 3 (d), similarly to FIG. 1 (b), by using the electron beam irradiation device 25 [Min-EB lab STM-chamber manufactured by Ushio Inc.] at 0.1 torr. 2 hours electron beam irradiation under nitrogen gas atmosphere, acceleration voltage 60 kV, tube current 0.3 mA, irradiation distance 30 mm, or in air, acceleration voltage 60 kV, tube current 0.3 mA, irradiation distance 5 mm did.
[0052]
The evaluation method is the same as in Examples 1 and 2 described above.
[0053]
As a result, the adhesion strength was 76 N, and the hardness of the hard carbon film was 57 GPa.
[0054]
It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.
[0055]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to improve the adhesion strength at the interface between different materials between the base material of the hard carbon film molded product and the carbon film and the strength of the hard carbon film molded product.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a manufacturing method according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a manufacturing method according to a second embodiment of the present invention.
FIG. 3 is a diagram illustrating a manufacturing method according to a third embodiment of the present invention.
[Explanation of symbols]
1

SUJ2 substrate

2, 12 Hard carbon film (a-C film)
3,13

Sputtering target

4,14,24 Deposition gas (argon + 10% methane gas)
5, 15, 25 Electron beam irradiation device 11 SUS304 base material 21 base material 22 first intermediate layer 23 second gradient composition intermediate layer

Claims

A surface layer of the hard carbon film and an iron-based substrate in contact with the surface layer, and an interface between the surface layer and the substrate is formed of a compound of silicon and iron or an additive element contained in the iron-based substrate. A hard carbon film molded body made of an amorphous carbon film which is amorphous and contains 0.1 at% or more and 30 at% or less of silicon as the surface layer and is irradiated with an electron beam accelerated to 100 kV or less.

A surface layer of the hard carbon film and an iron-based substrate in which the surface layer is in contact with an intermediate layer, and an interface between the intermediate layer and the substrate is formed of silicon and iron or an additive contained in the iron-based substrate. A hard carbon formed by irradiating an electron beam accelerated to 100 kV or less with an amorphous carbon film containing 0.1 at% or more and 30 at% or less of silicon as the intermediate layer. Coated molded body.

Form a surface layer of a hard carbon film, or a surface layer and an intermediate layer of a hard carbon film on a base material, and perform low-energy electron beam irradiation after the formation of the surface layer or the intermediate layer to deteriorate characteristics at low temperatures. A method for producing a hard carbon film molded body, wherein a diffusion reaction layer having high adhesiveness is formed without forming the same.

(A) a surface layer of a hard carbon film and an iron-based substrate in contact with the surface layer; and at the interface between the surface layer and the substrate, silicon and iron or an additive element contained in the iron-based substrate Forming an amorphous carbon film containing 0.1 at% or more and 30 at% or less of silicon as the surface layer,
(B) A method for producing a hard carbon film molded body, which comprises irradiating an electron beam accelerated to 100 kV or less.

(A) A surface layer of a hard carbon film and an iron-based substrate in which the surface layer is in contact with an intermediate layer, and at the interface between the intermediate layer and the substrate, silicon and iron or an iron-based substrate Forming an amorphous carbon film containing 0.1 at% or more and 30 at% or less of silicon as the intermediate layer, the compound being amorphous with an additive element contained in
(B) A method for producing a hard carbon film molded body, which comprises irradiating an electron beam accelerated to 100 kV or less.

The manufacturing method according to claim 3, 4 or 5 hard carbon film formed body according, atmospheric irradiation of the electron beam, or the hard carbon film formed body, characterized in that conducted in an inert gas atmosphere under reduced pressure Manufacturing method.