JPS5826423B2 - Chip-resistant, high permeability alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sendust-based high permeability alloy with particularly improved durability.

With the rapid development and spread of magnetic recording in recent years, there is a strong desire to develop magnetic materials for magnetic heads that have excellent magnetic properties, wear resistance, and shading resistance.

That is, conventionally, magnetic materials for magnetic helad cores, such as permalloy and ferrite, have been used, but as a result of the appearance of chromium oxide (CRO2) tape, which easily wears the mating material, and the spread of magnetic cards, permalloy has become less wear-resistant. However, there is a strong desire for a new magnetic material that can compensate for the drawbacks of both materials, such as the fact that ferrite has extremely poor shade resistance, especially when used with magnetic cards.

mosquito! Al-8i-Fe alloy has appeared as a material to meet the demands of
1933) was known as a superior magnetic material (Japanese Patent Publication No. 8-2407), and later rFerromagne
tism Bozorth, R.M., 1951
It was introduced as a sendust alloy in Jvan, No. 5t 1 and Reinhold, etc., and has come to be widely known as a magnetic material.

Later, improvements were made to this Sendust alloy, and 4.0~
8.0 wt%Al-8.0~11.0 wt%si
- In addition to the Sendust alloy with the basic composition of Fe as the balance, this Sendust alloy also contains Tt+Zr, Mn, Ge, Mo, Nb, and C.
u.

Sendust alloys have also appeared in which one or more of Be+WsTatHftPt group elements are added in a total amount of 0.01 to 3.5 wt%.

These Sendust alloys and Sendust-based alloys are F e
s Als A high magnetic permeability alloy whose main component is S 1. It has a Vickers hardness of 450 or more, and has excellent magnetic properties that surpass that of permalloy. It also has much better wear resistance than permalloy. Since it is extremely superior to ferrite in terms of shadowing properties, it is attracting attention as a magnetic material for future magnetic heads.

However, due to the recent rapid spread of magnetic cards and their increasing use under particularly harsh conditions such as unmanned ticket gates, even the above-mentioned Sendust alloys do not have sufficient wear resistance. There is a growing demand for magnetic materials that have better wear resistance and shading resistance than the alloys.

Therefore, the present inventors first prepared 0.0% of rare earth elements and/or phosphorus.
Sendust alloy or sendust-based alloy with wear resistance and high magnetic permeability by adding 01 to 1.0 wt%, and high magnetic permeability with improved wear resistance by adding a trace amount of boron (0,001 to 1 wt%). Sendust alloys and Sendust-based alloys were developed.

However, although most of these wear-resistant Sendust alloys and Sendust-based alloys are hard, they are also brittle, which causes cracks, chips, and polished surfaces during cutting, grinding, polishing, and other processing when used as core materials for magnetic heads. Defects such as peeling within the magnetic head are also becoming more likely to occur, which has delayed its practical use as a core material for magnetic heads, such as card reader heads, which require particularly wear-resistant properties.

Conventionally, as a countermeasure against this problem, based on the idea that the refinement of crystal grains is effective in immediately improving the properties, ZrNb, Ta,
Attempts have been made to refine the crystal grains by adding elements such as W, but this refinement of the grains does not lead to improvements in durability or properties, and on the contrary, as a result of the refinement of the grains, There were many cases where chipping was likely to occur.

Therefore, as a result of extensive experimental research on the addition of at least two types of elements in combination, the inventors of the present invention have determined that the durability of the Sendust alloy, the Sendust alloy, and the wear-resistant Sendust alloy can be improved by adding a combination of at least two elements: Ti and C. By containing these in combination within a specific range, the desired purpose could be achieved.

This is because Ti is the metal element with the strongest affinity for C,
When Ti and C are simultaneously contained in a sendust alloy or sendust-based alloy, TiC is generated and the T during solidification is
Fine particles of iC serve as seeds to grow crystals, and in this case, the above-mentioned Zr.

Unlike the case of adding elements such as Nb, Ta, and W, foreign phases do not precipitate at grain boundaries, and as a result, the effect of grain refinement remains the same! It is thought that durability is working to improve sexual performance.

However, in the present invention, the Ti content is set to 0.01 to 4.
5 wt%, C content limited to O,OO5~1.5 wt%, Ti O,01 wt test, CO,00
5w under the width plate, the durability due to grain refinement cannot be expected to be sufficiently improved; on the other hand, when Ti is 4.5wt% or more,
This is because magnetic permeability is impaired above 1.5 wt.

The mutual ratio of Ti and C is arbitrary within the range of the Ti content and C content mentioned above, but Ti:c (weight ratio) ~ 3:1 ~
It is most effective in the 8:1 range.

Sendust alloys and Sendust-based alloys as used in the present invention collectively refer to all high magnetic permeability alloys whose basic composition is Fe-A7Si, but they can be specifically classified into the following groups.

(1) Sendust alloy (hereinafter referred to as S alloy) with A7 content of 4.0 to 8.0 wt% and Si content of 8.
．． The reason why it is set at 0 to 11.0 wt% is that magnetic properties are impaired even if either of them is less than the lower limit or exceeds the upper limit.

Ti again? Z r * Mnt G e w
Mo + Nb, Cu, Be, W, Ta, Hf, a total of 0.01 to 3.5 wt% of one or more of the Pt group, P, a total of 0.01 of one or two rare earth elements. ~1.0
The reason for setting B to 0.001 to 1.0 wt% is that in any case, if the amount added is less than the lower limit, no improvement in wear resistance will be observed, and if it exceeds the upper limit, chipping will occur during processing. This is because the magnetic properties become worse and the magnetic properties are impaired.

Examples will be shown below to further enhance the effects of the present invention.

The alloy of the present invention and the conventional alloy IKy having the alloy compositions shown in Table 1 were melted by high frequency heating in a vacuum of 10-3 to 10-4 Hg, and then cast in a water-cooled copper crucible to form a 20 x 60 x 100 mm. A plate-shaped ingot was created.

After annealing these ingots in the atmosphere at 1000°C for 12 hours, the ingots were cut and ground to a 0.33
A thin plate with dimensions of
．． A 3 mm measurement ring was prepared, the impedance in the IKC was measured using a Maxwell bridge, and the effective magnetic permeability μe was calculated therefrom.

On the other hand, fire resistance is related to property, - 0.33X20X60m in H.
The number of defects with a length of 30 μm or more that occurred on a 60-meter edge of a thin plate with a size of m was compared.

The grinding conditions in this case are as follows.

Grinding machine feed speed 15m/min Grinding depth 10μ Grinding wheel used GC-120 (product name) rotation speed
285 OR, P-M As is clear from Table 1, the present invention alloys 9 to 36 in which Ti and C are added to the conventional sendust alloy or sendust-based alloy are the conventional sendust alloy 1 and the sendust-based alloy &2. It can be seen that compared to Arashi 8, it has an effective magnetic permeability μe that is almost the same as Arashi 8, and its durability is far superior.

On the other hand, it can be seen that the effective magnetic permeability μe or durability of the comparative alloys &371/40 in which the Ti content or C content is outside the range defined by the present invention is inferior.

That is, it can be seen that the effective magnetic permeability of the comparative alloys containing a large amount of Ti or C at 37°Arashi 39 is significantly reduced, while the comparative alloys /ff138 and ff440 containing a small amount of Ti or C have no improvement in durability.

As described above, the alloy of the present invention can prevent defects such as cracking, chipping, and peeling during the manufacturing process and/or use without deteriorating the effective magnetic permeability of conventional Sendust alloys or Sendust-based alloys. Therefore, it can be used as a core material for magnetic heads, etc., and has a remarkable effect.

Claims (1)

[Claims] I Al4.0-8.0wt, %, Si 8.0-1
Sendust alloy (S
), the alloy (S) contains Tt, Zr, Mn, Ge, Mo
, Nb. Sendust alloy (S'-1), alloy (S) or alloy (S'- Sendust alloy (S'-2), alloy (S), alloy (S'-1) in which P and one or two rare earth elements are added in a total of 0.01 to 1.0 wt'% to 1) Or alloy (S'-2) KB from 0.001 to 1. In the sendust-based alloy (S'-3) with Owt addition, a combination of Ti and C is further added to increase Ti0.01 to 4.5wt.
A durable, high magnetic permeability alloy characterized by containing 0,005 to 1.5 wt % of carbon.