JP2922346B2 - Heat-resistant Ti-based alloy - Google Patents
Heat-resistant Ti-based alloyInfo
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- JP2922346B2 JP2922346B2 JP27016591A JP27016591A JP2922346B2 JP 2922346 B2 JP2922346 B2 JP 2922346B2 JP 27016591 A JP27016591 A JP 27016591A JP 27016591 A JP27016591 A JP 27016591A JP 2922346 B2 JP2922346 B2 JP 2922346B2
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- coating layer
- layer
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- resistant
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、表面にＡｌ−Ｃｒ複合
拡散被覆層を有する耐熱性・耐酸化性に優れたＴｉ系合
金の改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a Ti-based alloy having an Al--Cr composite diffusion coating layer on its surface and having excellent heat resistance and oxidation resistance.
【０００２】[0002]
【従来の技術】チタン材料は、軽量で、機械的性質及び
耐食性にすぐれているので、特に工業用チタン及びＴｉ
−Ａｌ系合金、例えば５Ａｌ−３Ｓｎ系や６Ａｌ−４Ｖ
系合金が多用されているが、一般に耐熱的に使用する場
合には、使用温度は約５００℃が上限となる。Ｔｉ合金
を高温に加熱すると、合金は、空気及び水分と反応して
合金内に水素化合物・窒化物を形成して脆化し、また表
面に酸化物層を形成し、保持時間の経過に伴って酸化物
層は成長を続けるので、耐酸化性材料としては使用でき
ない。2. Description of the Related Art Titanium materials are lightweight and have excellent mechanical properties and corrosion resistance.
-Al alloys, for example, 5Al-3Sn or 6Al-4V
Although system alloys are frequently used, the upper limit of the operating temperature is generally about 500 ° C. when the alloy is generally used with heat resistance. When a Ti alloy is heated to a high temperature, the alloy reacts with air and moisture to form hydrides / nitrides in the alloy and become brittle, and also forms an oxide layer on the surface, and as the retention time elapses, The oxide layer continues to grow and cannot be used as an oxidation resistant material.
【０００３】このようなＴｉ−Ａｌ系合金の耐酸化性の
改善には、合金表面のＡｌ被覆処理が有効であることが
知られており、この処理によって、合金表面のＡｌ被覆
層はＴｉＡｌ3 相を形成して、その表面が酸化された場
合でも、酸化層は成長せず、耐酸化性を示す。また、Ｔ
ｉＡｌ3 は水素透過率が低いので、Ａｌ被覆層を有する
Ｔｉ系合金は水素脆化に対して抵抗を示す。Ａｌ被覆処
理を行ったこれらＴｉ−Ａｌ系合金は、５００℃以上の
高温では、軟化して機械的強度は低下するけれども、耐
熱材料として利用することができる。[0003] It is known that an Al coating treatment on the alloy surface is effective in improving the oxidation resistance of such a Ti-Al-based alloy, and by this treatment, the Al coating layer on the alloy surface becomes TiAl 3. Even when a phase is formed and its surface is oxidized, the oxide layer does not grow and exhibits oxidation resistance. Also, T
Since iAl 3 has a low hydrogen permeability, a Ti-based alloy having an Al coating layer exhibits resistance to hydrogen embrittlement. At high temperatures of 500 ° C. or higher, these Ti—Al-based alloys that have been subjected to Al coating treatment can be used as heat-resistant materials, although they soften and have reduced mechanical strength.
【０００４】また、耐熱性を改善したＴｉ系合金には、
合金中Ａｌ含有量を増加した１５〜３６％Ａｌ−Ｔｉ系
合金がある。この合金は、Ａｌ含有量の増加に伴って、
高温強度と耐酸化性が向上し、特に金属間化合物ＴｉＡ
ｌの組成を有する３４〜３６％Ａｌ−Ｔｉ合金は少量の
他成分を添加して、加工性・延性を付与し、インコネル
７１８相当の耐熱性がある。このＴｉＡｌ合金は、ジエ
ットエンジン圧縮機のステータベーン、ガスタービンの
ブレード、或いは自動車用エンジンバルブやターボチャ
ージャーのタービンロータ等の軽量耐熱部材としての用
途が注目されているが、これら合金の使用実用温度は耐
酸化性の点から約７００℃であって、７００℃以上の高
温では、表面酸化が顕著となって、寿命が低下する。[0004] In addition, Ti-based alloys having improved heat resistance include:
There is a 15-36% Al-Ti alloy in which the Al content in the alloy is increased. This alloy, with increasing Al content,
High temperature strength and oxidation resistance are improved.
The 34-36% Al-Ti alloy having a composition of l provides a small amount of other components to impart workability and ductility, and has heat resistance equivalent to Inconel 718. The use of this TiAl alloy as a lightweight heat-resistant member such as a stator vane of a jet engine compressor, a blade of a gas turbine, or an engine valve for an automobile or a turbine rotor of a turbocharger has attracted attention. Is about 700 ° C. from the viewpoint of oxidation resistance. At a high temperature of 700 ° C. or more, surface oxidation becomes remarkable, and the life is shortened.
【０００５】このような高Ａｌ−Ｔｉ合金にアルミニウ
ム浸透被覆処理をして、その表面に６０〜７０％Ａｌの
Ｔｉ−Ａｌ金属間化合物層を形成せしめて、高温大気中
での表面酸化を抑制する技術が知られている（特開平１
−１１１８５８号）。この場合、表面のＡｌ被覆層はＴ
ｉＡｌ3 相となり、７００℃以上の高温中であってもＡ
ｌ被覆層の酸化量を低下させて、耐酸化性を改善したも
のである。[0005] Such a high Al-Ti alloy is subjected to aluminum infiltration coating to form a 60-70% Al Ti-Al intermetallic compound layer on its surface, thereby suppressing surface oxidation in a high-temperature atmosphere. Is known (Japanese Unexamined Patent Publication No.
-111858). In this case, the Al coating layer on the surface is T
iAl 3 phase, A even at high temperature of 700 ° C or higher
(1) The oxidation resistance of the coating layer is reduced to reduce the oxidation amount.
【０００６】[0006]
【発明が解決しようとする課題】上記のＡｌ被覆層を表
面に成形した高Ａｌ−Ｔｉ合金においても、９００℃以
上の高温で使用される場合には、表面でのＡｌ被覆層中
のＴｉの酸化はなお無視し得ないほど進行し、Ａｌ被覆
層の層厚が減少して、その結果、表面肌荒れやスケール
を生じて寸法減少を生じるので、精密な耐熱部品におい
ては十分な耐酸化性を有するとは言えない。本発明は、
上記問題に鑑み、表面に有するＡｌ被覆層の耐酸化性特
性を改善した高Ａｌ−Ｔｉ合金その他の耐熱性Ｔｉ系合
金を提供せんとするものである。In the case of a high Al-Ti alloy having the above-mentioned Al coating layer formed on the surface, even when the alloy is used at a high temperature of 900 ° C. or higher, the Ti in the Al coating layer on the surface is not removed. Oxidation still proceeds to a negligible extent, and the thickness of the Al coating layer decreases, resulting in surface roughness and scale, resulting in a reduction in dimensions. I can't say it has. The present invention
In view of the above problems, an object of the present invention is to provide a high Al—Ti alloy and other heat-resistant Ti-based alloys in which the oxidation resistance of the Al coating layer on the surface is improved.
【０００７】[0007]
【課題を解決するための手段】本発明の耐熱性Ｔｉ系合
金は、Ｔｉ系合金母材の表面にＡｌ−Ｃｒ拡散被覆層を
有する耐熱性Ｔｉ系合金であって、該Ａｌ−Ｃｒ拡散被
覆層は、母材のＴｉ系合金中にＡｌが５０〜６５ｗｔ％
とＣｒが０．５〜７ｗｔ％含まれていることを特徴とす
るものである。また、本発明は、Ｔｉ系合金母材の表面
にＡｌが９０〜９９．５ｗｔ％とＣｒが０．５〜１０ｗ
ｔ％とから成るＡｌ−Ｃｒ合金層が形成された耐熱性Ｔ
ｉ系合金であって、高温下の使用過程で当該Ａｌ−Ｃｒ
合金層がＴｉ系合金母材へ拡散してＡｌ−Ｃｒ拡散被覆
層を形成し、該Ａｌ−Ｃｒ拡散被覆層にＡｌが５０〜６
５ｗｔ％とＣｒが０．５〜７ｗｔ％含まれるようにした
ことを特徴とする耐熱性Ｔｉ系合金が含まれる。The heat-resistant Ti-based alloy according to the present invention is a heat-resistant Ti-based alloy having an Al-Cr diffusion coating layer on the surface of a Ti-based alloy base material, wherein the Al-Cr diffusion coating is provided. The layer is composed of 50 to 65 wt% Al in the Ti-based alloy of the base material.
And 0.5 to 7 wt% of Cr. In addition, the present invention provides a method in which Al is 90 to 99.5 wt% and Cr is 0.5 to 10 w
heat resistance T on which an Al-Cr alloy layer consisting of
i-type alloy, which is used in the process of using the Al-Cr
The alloy layer diffuses into the Ti-based alloy base material to form an Al—Cr diffusion coating layer, and the Al—Cr diffusion coating layer contains 50 to 6 Al.
A heat-resistant Ti-based alloy characterized by containing 5 wt% and 0.5 to 7 wt% of Cr is included.
【０００８】本発明のＴｉ系合金には、工業用純チタ
ン、Ｔｉ−６Ａｌ−４Ｖ系合金やＴｉ−８Ａｌ−Ｓｎ系
合金などのＴｉ系合金や耐熱性のＴｉ−１４〜３６Ａｌ
系合金などが対象になる。[0008] The Ti-based alloy of the present invention includes industrial pure titanium, Ti-based alloys such as Ti-6Al-4V-based alloys and Ti-8Al-Sn-based alloys, and heat-resistant Ti-14-36Al.
For example, system alloys.
【０００９】Ａｌ−Ｃｒ拡散被覆層の形成には、Ａｌ粉
の粉末法による拡散被覆法、溶射法、肉盛法、ＰＶＤ
（物理的気相成長）法又はＣＶＤ（化学的気相成長）法
が適用できる。粉末法では、Ａｌ粉、Ｃｒ粉及びＡｌ2
Ｏ3 粉に少量の塩化アンモニウムを配合して加熱したポ
ット中に、Ｔｉ合金材料を埋設して保持する方法であ
り、保持過程で、表面に析出したＡｌ及びＣｒは内部に
浸透してＡｌ−Ｃｒ拡散被覆層を形成する。The Al-Cr diffusion coating layer is formed by a diffusion coating method using a powder method of Al powder, a thermal spraying method, a cladding method, a PVD method.
A (physical vapor deposition) method or a CVD (chemical vapor deposition) method can be applied. In the powder method, Al powder, Cr powder and Al 2
This is a method in which a Ti alloy material is buried and held in a pot heated by mixing a small amount of ammonium chloride with O 3 powder. During the holding process, Al and Cr deposited on the surface penetrate into the inside and Al- A Cr diffusion coating layer is formed.
【００１０】溶射法では、Ａｌ粉とＣｒ粉との混合粉
を、例えば、Ａｒガスによるプラズマ溶射法により、合
金材料表面に溶射してＡｌ−Ｃｒ合金層を形成する。次
いで使用前に非酸化性の高温雰囲気中で加熱してＴｉ合
金の材料母材と拡散合金化して、Ａｌ−Ｃｒ拡散被覆層
を形成せしめる。In the thermal spraying method, an Al-Cr alloy layer is formed by spraying a mixed powder of Al powder and Cr powder on the surface of an alloy material by, for example, a plasma spraying method using Ar gas. Next, before use, it is heated in a non-oxidizing high-temperature atmosphere to form a diffusion alloy with the Ti alloy material base material to form an Al—Cr diffusion coating layer.
【００１１】また、本発明におけるＡｌ−Ｃｒ合金層
は、上記の溶射法により形成され、Ｔｉ系合金の表面
に、Ａｌ９０〜９９．５ｗｔ％、Ｃｒ０．５〜１０ｗｔ
％から成る合金層に調製するものである。そして、上記
の拡散合金化の処理を省略して、そのまま使用に供され
るので、当該Ａｌ−Ｃｒ合金層は高温下の使用過程で上
記組成範囲のＡｌ−Ｃｒ拡散被覆層に形成されるのであ
る。Further, the Al—Cr alloy layer in the present invention is formed by the above-mentioned thermal spraying method, and the surface of the Ti-based alloy has 90 to 99.5 wt% of Al and 0.5 to 10 wt% of Cr.
% Of the alloy layer. Then, since the above-mentioned diffusion alloying treatment is omitted and the Al-Cr alloy layer is used as it is, the Al-Cr alloy layer is formed on the Al-Cr diffusion coating layer having the above composition range in a use process at a high temperature. is there.
【００１２】Ａｌ−Ｃｒ拡散被覆層の厚みは１５μｍ以
上であって、実用的には３００μｍ以下とするが、好ま
しくは１５０μｍ程度とするのが適当である。また、予
めＡｌ−Ｃｒ合金層を形成する場合もその厚みは、同様
に１５〜３００μｍとする。The thickness of the Al—Cr diffusion coating layer is 15 μm or more, and practically 300 μm or less, preferably about 150 μm. Also, in the case where an Al-Cr alloy layer is formed in advance, the thickness is similarly set to 15 to 300 m.
【００１３】[0013]
【実施例】本発明の耐熱性Ｔｉ系合金の実施例を以下に
示す。 （実施例１）供試材としては、Ｔｉ−３４％Ａｌ合金
で、直径８ｍｍ、長さ１０ｍｍの形状の試片を用いた。EXAMPLES Examples of the heat-resistant Ti-based alloy of the present invention will be described below. (Example 1) As a test material, a specimen of Ti-34% Al alloy having a diameter of 8 mm and a length of 10 mm was used.
【００１４】Ａｌ−Ｃｒ拡散被覆層の成形には、以下に
示す粉末法に依った。Ａｌ粉１０〜３０ｗｔ％、Ｃｒ粉
０〜６０ｗｔ％、塩化アンモニウム０．５ｗｔ％及び残
部アルミナ粉から成る種々の組成の拡散浸透処理剤を調
整した。この処理剤を耐熱性ポットに入れ、上記試片を
埋設して、７００℃〜１３００℃の温度で１０〜２０時
間加熱保持して、Ａｌ拡散浸透処理とＡｌ−Ｃｒ複合拡
散浸透処理を行った。The Al-Cr diffusion coating layer was formed by the following powder method. Diffusion infiltration treatment agents of various compositions consisting of 10 to 30 wt% of Al powder, 0 to 60 wt% of Cr powder, 0.5 wt% of ammonium chloride and the balance of alumina powder were prepared. This treating agent was put into a heat-resistant pot, the specimen was buried, and heated and held at a temperature of 700 ° C. to 1300 ° C. for 10 to 20 hours to perform Al diffusion and penetration treatment and Al—Cr composite diffusion and penetration treatment. .
【００１５】この拡散浸透処理においては、Ａｌ−Ｃｒ
拡散被覆層中のＡｌ濃度が５０〜６５％になるように、
またＡｌ−Ｃｒ拡散被覆層の厚みを５０μｍの薄膜と１
５０μｍ厚膜の二水準に層別するように狙い、各水準に
おいて、Ａｌ−Ｃｒ拡散被覆層中のＣｒ濃度が０〜１０
ｗｔ％の範囲に変化するように処理剤中のＡｌ粉とＣｒ
粉の配合量を調整した。この処理後、各試験片を切断研
磨して、顕微鏡観察を行いＡｌ−Ｃｒ拡散被覆層の厚み
を測定し、ＥＰＭＡ分析によるＡｌ−Ｃｒ拡散被覆層の
Ａｌ及びＡＣｒの濃度測定を行った。In this diffusion infiltration treatment, Al-Cr
So that the Al concentration in the diffusion coating layer is 50 to 65%.
The thickness of the Al—Cr diffusion coating layer is set to 50 μm and 1 μm.
Aiming at stratification into two levels of a 50 μm thick film, in each level, the Cr concentration in the Al—Cr diffusion coating layer is 0 to 10
Al powder and Cr in the treating agent to change to the range of wt%.
The blending amount of the powder was adjusted. After this treatment, each test piece was cut and polished, observed under a microscope, the thickness of the Al-Cr diffusion coating layer was measured, and the concentrations of Al and ACr in the Al-Cr diffusion coating layer were measured by EPMA analysis.
【００１６】図１は、Ａｌ−Ｃｒ拡散被覆層厚さ１５０
μｍ、表面Ｃｒ濃度０．５ｗｔ％の試片について、高温
酸化試験前の表層部断面の顕微鏡写真を示すが、表層部
には明瞭なＡｌ−Ｃｒ拡散被覆層が認められる。FIG. 1 shows an Al-Cr diffusion coating layer thickness of 150.
A micrograph of a cross section of the surface layer before the high-temperature oxidation test is shown for a test piece having a thickness of 0.5 μm and a surface Cr concentration of 0.5 wt%, and a clear Al—Cr diffusion coating layer is observed in the surface layer.
【００１７】図２は、同一試片の表層部のＡｌ濃度及び
Ｃｒ濃度のＥＰＭＡによる分析結果であって、表面近傍
内側に約６３％Ａｌの第一層と、その内部に５３％Ａｌ
の第二層とが認められ、さらに内側に母材中のＡｌ濃度
まで漸減する拡散層がある。第一層についてはＴｉＡｌ
3 相と、第二層はＴｉＡｌ2 相と同定した。Ｃｒ濃度に
ついては、表面から母材界面に向けてほぼ一様に漸減し
ている。FIG. 2 shows the results of EPMA analysis of the Al concentration and the Cr concentration of the surface layer of the same specimen. The first layer is about 63% Al inside the vicinity of the surface, and the 53% Al
And a diffusion layer which gradually decreases to the Al concentration in the base material. TiAl for the first layer
The three phases and the second layer were identified as a TiAl 2 phase. The Cr concentration gradually decreased almost uniformly from the surface toward the base material interface.
【００１８】次に、上記各試片を大気中で１０００℃の
温度で１００時間加熱保持して、高温酸化試験を行い、
試片の重量変化から酸化増量を算出し、耐酸化性の評価
を行った。以上の結果をまとめて表１に示した。Next, each of the above test pieces was heated and held in the atmosphere at a temperature of 1000 ° C. for 100 hours to perform a high-temperature oxidation test.
The oxidation increase was calculated from the weight change of the test piece, and the oxidation resistance was evaluated. Table 1 summarizes the above results.
【００１９】[0019]
【表１】 [Table 1]
【００２０】表１から、処理材中のＡｌ粉配合量が１０
％の場合では、Ａｌ−Ｃｒ拡散被覆層の厚みは、４０〜
９０μｍと薄く、Ａｌ濃度は６０％以下でＴｉＡｌ2 相
である（表中試料番号３〜９）が、Ａｌ粉配合量２０〜
３０％の場合では、Ａｌ濃度は約６３％に増加し、Ｔｉ
Ａｌ3 相が現れることがわかる（表中試料番号１０〜１
４）。From Table 1, it can be seen that the content of Al powder in the treated material is 10%.
%, The thickness of the Al—Cr diffusion coating layer is 40 to
It is as thin as 90 μm, the Al concentration is 60% or less and it is a TiAl 2 phase (sample numbers 3 to 9 in the table), but the Al powder blending amount is 20 to
In the case of 30%, the Al concentration increases to about 63% and Ti
It can be seen that an Al 3 phase appears (sample numbers 10 to 1 in the table).
4).
【００２１】図３には、１０００℃の温度で１００時間
加熱保持後の試片につき、表層部断面の顕微鏡写真を示
すが、図３（Ａ）は、表１中の試料番号９の試片であっ
て、Ａｌ−Ｃｒ拡散被覆層の表面に酸化スケールが生成
していることが判る。これに対して、同図（Ｂ）は、試
料番号７の試片であるが、酸化層は殆ど生じていない。FIG. 3 shows a micrograph of the cross section of the surface layer of the test piece after heating and holding at a temperature of 1000 ° C. for 100 hours. FIG. 3 (A) shows the test piece of sample No. 9 in Table 1. It can be seen that oxide scale is generated on the surface of the Al—Cr diffusion coating layer. On the other hand, FIG. 3B shows the sample of sample No. 7, but almost no oxide layer is formed.
【００２２】図４は、Ａｌ−Ｃｒ拡散被覆層の厚みを４
０〜９０μｍの薄膜と１４０〜１５０μｍの厚膜に層別
して、Ａｌ−Ｃｒ拡散被覆層のＣｒ濃度と１０００℃×
１００時間加熱後の酸化増量との関係を示したものであ
る。この図から、Ａｌ−Ｃｒ拡散被覆層が厚膜である方
が薄膜に比して酸化増量が少ないが、ともに表面のＣｒ
濃度が０．５％以上となると酸化増量は低下し、耐酸化
性付与に有効であり、約８％以上に増加すれば返って酸
化増量は増加する。表面のＣｒ濃度が０．５〜７．０％
の範囲が耐酸化性にとってよいことが判る。特に３〜５
％Ｃｒの濃度において、上記範囲の層厚に影響されず
に、耐酸化性はもっとも優れている。FIG. 4 shows that the thickness of the Al—Cr diffusion coating layer is 4
It is divided into a thin film having a thickness of 0 to 90 μm and a thick film having a thickness of 140 to 150 μm.
It shows the relationship with the increase in oxidation after heating for 100 hours. From this figure, it can be seen that the thicker the Al—Cr diffusion coating layer is, the smaller the oxidation increase is compared to the thin film,
When the concentration is 0.5% or more, the increase in oxidation decreases, which is effective for imparting oxidation resistance. When the concentration increases to about 8% or more, the increase in oxidation returns. The Cr concentration on the surface is 0.5 to 7.0%
It can be seen that the range of is good for oxidation resistance. Especially 3-5
At the concentration of% Cr, the oxidation resistance is the best, without being affected by the layer thickness in the above range.
【００２３】（実施例２）次にＴｉＡｌ3 合金粉末のプ
ラズマ溶射法による実施例を示す。純Ｔｉの形状５０×
１００×５ｍｍの基材の表面に、ＴｉＡｌ3 粉末９７％
とＣｒ粉末３％との混合微粉を、Ａｒ−Ｈ2 混合ガスを
搬送ガスとしてプラズマ溶射を行った。溶射条件は、搬
送ガスＡｒ６．３×１０-4Ｎｍ3 ／sec とＨ2 ５．５×
１０-5Ｎｍ3 ／sec の供給速度で、粉末の供給量０．１
３ｇ／sec で、雰囲気圧力２０．０ＫＰ、基材の移動速
度５ｍｍ／sec であった。溶射後の被覆層の厚みは約１
５０μｍであった。(Embodiment 2) Next, an embodiment of the plasma spraying method of TiAl 3 alloy powder will be described. Pure Ti shape 50x
97% TiAl 3 powder on the surface of a 100 × 5 mm substrate
The co-micronized with Cr powder 3% and were subjected to plasma spraying as the carrier gas Ar-H 2 mixed gas. The thermal spraying conditions were as follows: carrier gas Ar 6.3 × 10 −4 Nm 3 / sec and H 2 5.5 ×
At a feed rate of 10 −5 Nm 3 / sec, a powder feed rate of 0.1
At 3 g / sec, the atmospheric pressure was 20.0 KP, and the moving speed of the substrate was 5 mm / sec. The thickness of the coating layer after thermal spraying is about 1
It was 50 μm.
【００２４】次に、溶射材を真空中で１２００℃に７２
時間加熱焼鈍して被覆層の拡散均一化処理を行った。Ｘ
線回析により、被覆層の生成物を同定してほぼ均一なＴ
ｉＡｌ3 相のＡｌ−Ｃｒ拡散被覆層が形成されていた。
またＥＰＭＡによる分析によりＣｒ濃度は表面層で２．
７％であった。Next, the sprayed material is heated to 1200 ° C. in vacuum for 72 hours.
The coating was subjected to heat annealing for a uniform diffusion time. X
By the line diffraction, the product of the coating layer is identified and almost uniform T
An i-Al 3 phase Al—Cr diffusion coating layer was formed.
According to the analysis by EPMA, the Cr concentration in the surface layer was 2.C.
7%.
【００２５】また、Ｃｒ粉末を配合しないで、ＴｉＡｌ
3 粉末のみを、上記実施例と同一条件でプラズマ溶射と
熱処理をした材料を比較材とした。拡散被覆層はＴｉＡ
ｌ3相から成り、Ｃｒは検出されなかった。In addition, without blending Cr powder, TiAl
A material obtained by subjecting only three powders to plasma spraying and heat treatment under the same conditions as in the above example was used as a comparative material. The diffusion coating layer is TiA
consists of l 3-phase, Cr was not detected.
【００２６】本試験材及び比較材を、大気中１０００℃
で１００時間加熱保持して、表面酸化の状態を観察し
た。本試験材は、表面が褐色に変色していたのに対し
て、比較材は厚さ約１００μｍ程度のスケールが生成
し、スケールが剥離しているのが見られた。The test material and the comparative material were heated at 1000 ° C. in the atmosphere.
For 100 hours, and the state of surface oxidation was observed. While the surface of the test material was discolored to brown, the comparative material formed a scale having a thickness of about 100 μm, and it was observed that the scale was peeled off.
【００２７】[0027]
【作用及び効果】Ｔｉ系合金母材の表層のＡｌ−Ｃｒ拡
散被覆層は、Ａｌ５０〜６５％含有するのでＴｉＡｌ3
相又はＴｉＡｌ2 相によって形成されているが、高温の
酸化性雰囲気中にあって、Ａｌが酸化され、Ｔｉ酸化物
を含むアルミナ相の酸化物薄膜となる。Ａｌ−Ｃｒ拡散
被覆層にＣｒを少量含むと、１０００℃の酸化性高温雰
囲気中にあっても、最表面のアルミナ相からＴｉＡｌ3
相への酸素の拡散移動を阻止して、アルミナ相の酸化物
層は成長せず、かつ緻密安定であるから剥離しない。Ａ
ｌ−Ｃｒ拡散被覆層中のＣｒ濃度が約８％以上に増加す
ると、アルミナ相の酸化層は成長して、耐酸化性を悪く
する。この原因は表面に肌荒れを生じ、表面近傍が多孔
性となるので、均一なアルミナ層が形成されないためと
考えられる。[Operation and Effect] Since the Al—Cr diffusion coating layer on the surface of the Ti-based alloy base material contains 50 to 65% Al, TiAl 3
Although formed of a phase or a TiAl 2 phase, in a high-temperature oxidizing atmosphere, Al is oxidized to form an oxide thin film of an alumina phase containing Ti oxide. When a small amount of Cr is contained in the Al-Cr diffusion coating layer, even in an oxidizing high-temperature atmosphere at 1000 ° C, TiAl 3
The diffusion transfer of oxygen to the phase is prevented, and the oxide layer of the alumina phase does not grow, and does not peel because it is dense and stable. A
When the Cr concentration in the l-Cr diffusion coating layer is increased to about 8% or more, the oxide layer of the alumina phase grows and deteriorates the oxidation resistance. This is considered to be because the surface becomes rough and the vicinity of the surface becomes porous, so that a uniform alumina layer is not formed.
【００２８】また、Ｔｉ系合金母材の表層にＡｌ−Ｃｒ
合金層を形成しておけば、高温の酸化性雰囲気中での使
用過程で、当該Ａｌ−Ｃｒ合金層は合金母材と拡散反応
して、Ａｌ５０〜６５％含有するのでＴｉＡｌ3 相又は
ＴｉＡｌ2 相から成るＡｌ−Ｃｒ拡散被覆層を形成し
て、耐酸化性を発現する。Further, the surface layer of the Ti-based alloy base material is made of Al-Cr.
If an alloy layer is formed, the Al-Cr alloy layer undergoes a diffusion reaction with the alloy base material during use in a high-temperature oxidizing atmosphere and contains 50 to 65% of Al, so that the TiAl 3 phase or TiAl 2 An Al—Cr diffusion coating layer composed of a phase is formed to exhibit oxidation resistance.
【００２９】本発明の耐熱性Ｔｉ系合金を実施すれば、
耐酸化性にすぐれた耐熱合金が得られる。特にＴｉ−１
４〜３６％Ａｌ合金を母材にすれば、実用的な使用温度
１０５０℃程度の耐熱材料として利用することができ
る。By implementing the heat-resistant Ti-based alloy of the present invention,
A heat-resistant alloy with excellent oxidation resistance can be obtained. Especially Ti-1
If a 4-36% Al alloy is used as a base material, it can be used as a practical heat-resistant material at a working temperature of about 1050 ° C.
【図１】Ａｌ−Ｃｒ拡散被覆層が形成されたＴｉ−Ａｌ
合金の高温酸化試験前における断面の金属組織を示す光
学顕微鏡写真（倍率；１００、腐食液；塩酸１．５ｍｌ
＋硝酸２．５ｍｌ＋フッ酸１ｍｌ＋水９５ｍｌの混合
液）。FIG. 1 shows a Ti—Al having an Al—Cr diffusion coating layer formed thereon.
Optical micrograph showing the metallographic structure of the cross section before the high-temperature oxidation test of the alloy (magnification: 100, etching solution: hydrochloric acid 1.5 ml)
+2.5 ml of nitric acid + 1 ml of hydrofluoric acid + 95 ml of water).
【図２】Ａｌ−Ｃｒ拡散被覆層と近接する母材のＥＰＭ
Ａ分析によるＡｌとＣｒの濃度曲線図。FIG. 2 shows an EPM of a base material adjacent to an Al—Cr diffusion coating layer.
FIG. 4 is a concentration curve diagram of Al and Cr by A analysis.
【図３】Ａｌ−Ｃｒ拡散被覆層が形成されたＴｉ−Ａｌ
合金の高温酸化試験をした後の断面金属組織を示す光学
顕微鏡写真（倍率；１００、腐食液；図１同様混合
液）。FIG. 3 shows a Ti—Al having an Al—Cr diffusion coating layer formed thereon.
1 is an optical microscope photograph (magnification: 100, corrosive liquid; mixed liquid similar to FIG. 1) showing a cross-sectional metal structure after a high-temperature oxidation test of the alloy.
【図４】加熱処理後の酸化増量とＣｒ濃度との関係を示
す図。FIG. 4 is a graph showing the relationship between the amount of increased oxidation after heat treatment and the Cr concentration.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 吉川 利平 滋賀県甲賀郡甲西町大池町８番地 日本 カロライズ工業株式会社内 (72)発明者 末安 正信 滋賀県甲賀郡甲西町大池町８番地 日本 カロライズ工業株式会社内 (56)参考文献 特公 昭55−10662（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.6，ＤＢ名) C23C 10/14 - 14/16 C23C 10/28 - 10/58 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Rihei Yoshikawa, 8th, Oikecho, Kosai-cho, Koga-gun, Shiga Japan Inside (72) Inventor Masanobu Suean 8th, Oike-cho, Kosai-cho, Koga-gun, Shiga Japan, Japan Incorporated (56) References JP-B-55-10662 (JP, B2) (58) Fields investigated (Int. Cl. 6 , DB name) C23C 10/14-14/16 C23C 10/28-10 / 58
Claims (3)
被覆層を有する耐熱性Ｔｉ系合金であって、該Ａｌ−Ｃ
ｒ拡散被覆層は、母材のＴｉ系合金中にＡｌが５０〜６
５ｗｔ％とＣｒが０．５〜７ｗｔ％含まれていることを
特徴とする耐熱性Ｔｉ系合金。1. A heat-resistant Ti-based alloy having an Al-Cr diffusion coating layer on a surface of a Ti-based alloy base material, wherein the Al-C
The r-diffusion coating layer contains 50 to 6 Al in the base Ti alloy.
A heat-resistant Ti-based alloy comprising 5 wt% and 0.5 to 7 wt% Cr.
９．５ｗｔ％とＣｒが０．５〜１０ｗｔ％とから成るＡ
ｌ−Ｃｒ合金層が形成された耐熱性Ｔｉ系合金であっ
て、高温下の使用過程で当該Ａｌ−Ｃｒ合金層がＴｉ系
合金母材へ拡散してＡｌ−Ｃｒ拡散被覆層を形成し、該
Ａｌ−Ｃｒ拡散被覆層にＡｌが５０〜６５ｗｔ％とＣｒ
が０．５〜７ｗｔ％含まれるようにしたことを特徴とす
る耐熱性Ｔｉ系合金。2. The method according to claim 1, wherein the surface of the Ti alloy base material contains 90 to 9 Al.
A consisting of 9.5 wt% and 0.5 to 10 wt% Cr
a heat-resistant Ti-based alloy having an l-Cr alloy layer formed thereon, wherein the Al-Cr alloy layer diffuses into the Ti-based alloy base material during use at a high temperature to form an Al-Cr diffusion coating layer, The Al-Cr diffusion coating layer contains 50 to 65 wt% of Al and Cr.
Is contained at 0.5 to 7 wt%.
％のＡｌを含有してなる請求項１又は２記載の耐熱性Ｔ
ｉ系合金。3. The Ti-based alloy base material is 14 to 36 wt.
3. The heat-resistant T according to claim 1, wherein the heat-resistant T contains at least one Al.
i-based alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27016591A JP2922346B2 (en) | 1991-09-21 | 1991-09-21 | Heat-resistant Ti-based alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27016591A JP2922346B2 (en) | 1991-09-21 | 1991-09-21 | Heat-resistant Ti-based alloy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0693412A JPH0693412A (en) | 1994-04-05 |
| JP2922346B2 true JP2922346B2 (en) | 1999-07-19 |
Family
ID=17482444
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27016591A Expired - Fee Related JP2922346B2 (en) | 1991-09-21 | 1991-09-21 | Heat-resistant Ti-based alloy |
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| Country | Link |
|---|---|
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Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE69614136T2 (en) * | 1995-11-08 | 2002-03-21 | Citizen Watch Co Ltd | Surface hardened material based on titanium and method for surface hardening of titanium material |
| JP3361072B2 (en) | 1998-02-20 | 2003-01-07 | 株式会社豊田中央研究所 | Method for producing metal member having excellent oxidation resistance |
| KR100305728B1 (en) * | 1999-08-30 | 2001-09-24 | 이종훈 | Powder Composition for Simultaneous Coating of Chrome and Aluminium on Metal Surfaces and Coating Method Thereof |
| DE19949541C2 (en) * | 1999-10-14 | 2002-02-28 | Forschungszentrum Juelich Gmbh | Metallic component with layer and manufacturing process for such a layer |
| JP3976599B2 (en) * | 2002-03-27 | 2007-09-19 | 独立行政法人科学技術振興機構 | Heat resistant Ti alloy material excellent in high temperature corrosion resistance and oxidation resistance and method for producing the same |
| JP6340770B2 (en) * | 2013-10-22 | 2018-06-13 | 新日鐵住金株式会社 | Titanium alloy material excellent in hydrogen absorption resistance and method for producing the same |
| JP6499998B2 (en) * | 2016-06-27 | 2019-04-10 | 株式会社増田酸素工業所 | Method for forming surface layer of molten metal processing member |
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| Publication number | Publication date |
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| JPH0693412A (en) | 1994-04-05 |
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