【発明の詳細な説明】[Detailed description of the invention]
本発明は磁気ヘツド用非晶質合金に係わり、特
に耐摩耗に優れた磁気ヘツド用非晶質合金に関す
るものである。
従来、磁気ヘツドに用いられる高透磁率金属材
料としては、結晶構造を有するFe―Ni合金、Fe
―Si―Al合金などがあるが、Fe―Ni合金（パー
マロイ）は透磁率が高いが耐摩耗性が悪く、Fe
―Si―Al合金（センダスト）は耐摩耗性は優れ
るが脆いため塑性加工が非常に困難であるという
欠点を有している。
最近、結晶構造を持たない非晶質合金におい
て、すぐれた磁気的及び機械的特性が見出され
た。特にCoとFeの原子比が94：６付近の非晶質
合金は磁歪が零付近になり、透磁率が高いことが
知られているが、熱的安定性に劣るという欠点を
有している。本発明者らはCoの一部をさらに、
Nb，Cr，Ta，Mo，Ｗ，Ti，Ｖなどの元素で置
換（特にNbで置換する事が好ましい。）すると透
磁率が向上するとともに熱的安定性が改善される
ことを見出した。
これらの非晶質合金はビツカース硬度が1000に
も達する大きな値を示すものの磁気ヘツドに使用
した場合、テープによるヘツド摩耗が一般に大き
いことが判明し、実用上大きな問題となつてい
た。また耐食性もヘツド材料として重要な要求さ
れる特性であるが、従来の高透磁率非晶質合金は
必ずしも十分ではなかつた。
本発明は上記の点に鑑み、耐摩耗性および耐食
性に優れ、かつ高透磁率を示し、熱安定性に優れ
た磁気ヘツド用非晶質合金を提供することを目的
とする。
本発明は原子％で（Co1―ａ―bFeaMb）100−
ｘ―ySixBy（ただしＭはTi，Ｖ，Cr，Mn，Ni，
Zr，Nb，Mo，Ｗ，Cuのうち少くとも１種、ａ
は0.04〜0.07、ｂは0.005〜0.10、ｘは８〜16、ｙ
は４〜6.5）から成ることを特徴とする耐摩耗性
に優れた磁気ヘツド用高透磁率非晶質合金であ
る。
なお本発明非晶質合金における組成比の限定理
由は以下の如きである。
まずＢは非晶質化を助成すると共に耐摩耗性を
改善する元素であるが、４％未満では非晶質合金
の製造が困難なばかりか高透磁率をもつことが不
可能になり、6.5％を越えると耐食性および耐摩
耗が悪くなるのでこの範囲とした。Siは非晶質化
を助成する元素であるが、８％未満では幅の広い
非晶質合金の作製が困難であり、16％を越えると
磁束密度が7500G以下になるので、この範囲とし
た。Feを４〜７原子％としたのはこの範囲外で
は高い透磁率が得られないからである。またTi，
Ｖ，Cr，Mn，Ni，Zr，Nb，Mo，Ｗ，Cuの少
なくとも１種からなるＭの含有量をｂ＝0.005〜
0.10としたのは0.005未満では透磁率の増加、保
磁力の減少、熱的安定性の向上という効果が得ら
れず、0.10を越えると磁束密度が7.500G以下に低
下するからである。
以下本発明を実施例を用いて詳細に説明する。
実施例 １
非晶質合金は圧延急冷法を用いて作製した。即
ち、２つの高速回転するロール間に石英管ノズル
より所望の組成比の溶融合金をアルゴンガス圧に
よつて噴出させ急冷して幅1.2mm、厚さ40μｍ、長
さ10ｍの薄帯試料を作製した。この材料を外径
10φ、内径6φのリングに打抜き450℃で10分熱処
理後、絶縁紙をはさんで10枚ラミネートし、１
次、２次コイルを巻いて透磁率および直流磁化曲
線を測定した。透磁率はマツクスウエルブリツジ
を用いて、直流磁化曲線は自動自記磁束計を用い
て測定した。また12mm幅薄帯よりオーデイオ用ヘ
ツド形状を打抜き、ヘツドを試作して耐摩耗性を
評価した。摩耗は、γFe2O3塗布のオーデイオ用
カセツトテープの100時間走行後のヘツドの摩耗
量を表面粗さ計を用いて測定した。得られた1k
Hzにおける実効透磁率（μ／ｋ）飽和磁化および
摩耗量及び合金組成をあわせて第１表に示す。第
１表には比較例として（Co0.90Fe0.06Cr0.04）
75Si10B15の結果も示す。
第１表より本発明の非晶質合金は耐摩耗性が優
れていることがわかる。またTi，Ｖ，Ni，Zr，
Nb，Mo，Ｗ，Cuも同様の結果を得ることがで
きる。
The present invention relates to an amorphous alloy for magnetic heads, and more particularly to an amorphous alloy for magnetic heads that has excellent wear resistance. Conventionally, high magnetic permeability metal materials used in magnetic heads include Fe--Ni alloys with crystal structures, Fe
-There are Si-Al alloys, but Fe-Ni alloys (permalloy) have high magnetic permeability but poor wear resistance, and Fe-Ni alloys (permalloy) have high magnetic permeability but poor wear resistance.
-Si-Al alloy (sendust) has excellent wear resistance, but has the disadvantage of being brittle and extremely difficult to plastically work. Recently, excellent magnetic and mechanical properties have been discovered in amorphous alloys that do not have a crystalline structure. In particular, amorphous alloys with an atomic ratio of Co and Fe around 94:6 have magnetostriction near zero and are known to have high magnetic permeability, but they have the disadvantage of poor thermal stability. . The present inventors further changed a part of Co to
It has been found that substitution with elements such as Nb, Cr, Ta, Mo, W, Ti, V (substitution with Nb is particularly preferred) improves magnetic permeability and thermal stability. Although these amorphous alloys exhibit large Vickers hardness values of up to 1000, when used in magnetic heads, it has been found that head wear due to tape is generally large, which has been a major problem in practice. Corrosion resistance is also an important property required for head materials, but conventional high permeability amorphous alloys have not always been sufficient. In view of the above points, an object of the present invention is to provide an amorphous alloy for a magnetic head that has excellent wear resistance and corrosion resistance, high magnetic permeability, and excellent thermal stability. In the present invention, (Co 1 −a−bFeaMb) 100 −
x-ySixBy (where M is Ti, V, Cr, Mn, Ni,
At least one of Zr, Nb, Mo, W, Cu, a
is 0.04-0.07, b is 0.005-0.10, x is 8-16, y
is a high magnetic permeability amorphous alloy for magnetic heads with excellent wear resistance, which is characterized by consisting of 4 to 6.5). The reasons for limiting the composition ratio in the amorphous alloy of the present invention are as follows. First of all, B is an element that supports amorphization and improves wear resistance, but if it is less than 4%, it is not only difficult to produce an amorphous alloy but also impossible to have high magnetic permeability. %, corrosion resistance and wear resistance deteriorate, so this range was set. Si is an element that supports amorphization, but if it is less than 8%, it is difficult to create a wide amorphous alloy, and if it exceeds 16%, the magnetic flux density will be less than 7500G, so this range was chosen. . The reason why Fe is set at 4 to 7 atomic % is that high magnetic permeability cannot be obtained outside this range. Also Ti,
The content of M consisting of at least one of V, Cr, Mn, Ni, Zr, Nb, Mo, W, and Cu is b = 0.005 ~
The reason why it is set to 0.10 is because if it is less than 0.005, the effects of increasing magnetic permeability, decreasing coercive force, and improving thermal stability cannot be obtained, and if it exceeds 0.10, the magnetic flux density decreases to 7.500 G or less. The present invention will be described in detail below using examples. Example 1 An amorphous alloy was produced using a rolling quenching method. That is, a molten alloy with a desired composition ratio is jetted between two high-speed rotating rolls from a quartz tube nozzle using argon gas pressure, and is rapidly cooled to produce a ribbon sample with a width of 1.2 mm, a thickness of 40 μm, and a length of 10 m. did. This material has an outer diameter
Punch out a ring with a diameter of 10φ and an inner diameter of 6φ, heat treat it at 450℃ for 10 minutes, then laminate 10 sheets with insulating paper in between.
Next, a secondary coil was wound and the magnetic permeability and DC magnetization curve were measured. The magnetic permeability was measured using a Maxwell bridge, and the DC magnetization curve was measured using an automatic self-recording magnetometer. We also punched out the shape of an audio head from a 12mm wide thin strip, produced a prototype head, and evaluated its wear resistance. Wear was measured by using a surface roughness meter to measure the amount of wear on the head of an audio cassette tape coated with γFe 2 O 3 after running for 100 hours. 1k obtained
The effective magnetic permeability (μ/k), saturation magnetization, wear amount, and alloy composition at Hz are also shown in Table 1. Table 1 shows a comparative example (Co 0.90 Fe 0.06 Cr 0.04 )
Results for 75 Si 10 B 15 are also shown. Table 1 shows that the amorphous alloy of the present invention has excellent wear resistance. Also Ti, V, Ni, Zr,
Similar results can be obtained with Nb, Mo, W, and Cu.
【表】
実施例 ２
（Co0.90Fe0.06Cr0.04）78Si22―yBy非晶質合金の
12幅薄帯を実施例１と同じ方法を用いて作製し、
実施例１と同じ方法を用いてヘツド試作およびヘ
ツド摩耗量を測定した。得られた結果を第１図に
示す。図よりＢ量とともに摩耗量は増大し、Ｂを
6.5原子％以下とすれば摩耗量は1μｍ以下となる
ことがわかる。
実施例 ３
第１図に示した非晶質合金の耐食性を定電位法
を用いて水中で測定し、分極抵抗（Rp）を求め
た。得られた結果を第２図に示す。図よりＢの減
少とともに分極抵抗が増大し、耐食性が向上する
ことがわかる。特にＢが6.5原子％以下ではRp＞
2600Ωとなりパーマロイよりも優れた耐食性を示
す。
以上の如く本発明に係る磁気ヘツド用非晶質合
金は、優れた磁気特性を有すると共に、特に耐摩
耗性、耐食性が優れており磁気ヘツドに最適なも
のと言える。[Table] Example 2 (Co 0.90 Fe 0.06 Cr 0.04 ) 78 Si 22 -yBy amorphous alloy
A 12-width ribbon was produced using the same method as in Example 1,
Using the same method as in Example 1, a trial head was produced and the amount of head wear was measured. The results obtained are shown in FIG. From the figure, the amount of wear increases with the amount of B.
It can be seen that if the content is 6.5 atomic % or less, the amount of wear becomes 1 μm or less. Example 3 The corrosion resistance of the amorphous alloy shown in FIG. 1 was measured in water using a constant potential method, and the polarization resistance (Rp) was determined. The results obtained are shown in FIG. It can be seen from the figure that as B decreases, polarization resistance increases and corrosion resistance improves. Especially when B is less than 6.5 atomic%, Rp＞
It has a resistance of 2600Ω and exhibits better corrosion resistance than permalloy. As described above, the amorphous alloy for magnetic heads according to the present invention has excellent magnetic properties and particularly excellent wear resistance and corrosion resistance, and can be said to be optimal for magnetic heads.
【図面の簡単な説明】[Brief explanation of drawings]
第１図乃至第２図は本発明に係る非晶質合金の
諸特性を示す曲線図。
1 and 2 are curve diagrams showing various characteristics of the amorphous alloy according to the present invention.