JPS5922781B2 - Wear resistant high permeability high saturation magnetic flux density alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Centast-based high permeability high saturation magnetic flux density alloy which has high magnetic permeability at high frequencies and has significantly improved wear resistance.

Currently, Centast alloys are already being used for applications such as digital and audio heads, but their wear resistance is not very good, being 3 to 5 times that of high-hardness permalloy and about 1/10 that of ferrite. Improvement in wear resistance is required.

Recently, recording tapes with high coercive force have appeared, and in order to reduce recording distortion, a head core material with high saturation magnetic flux density is required, and for this purpose, centast alloys that have improved wear resistance and do not reduce saturation magnetic flux density are needed. It has come to be hoped that the emergence of

In order to deal with this problem, the present inventor conducted research on alloy compositions to improve wear resistance without reducing the saturation magnetic flux density of centast alloys, and found that Fe-Si
-By adding a small amount of C to an Al-based centast alloy, we succeeded in significantly improving wear resistance without significantly reducing effective magnetic permeability and saturation magnetic flux density. That is, the alloy of the present invention has 5i4-11wt%, A13-8wt%, C0.01
This relates to a wear-resistant, high magnetic permeability, high saturation magnetic flux density alloy consisting of ~2.0 wt% and the balance Fe, and the C content is 0.01 wt% to 2.0 wt%. This is because if the C content is below, the effect of significantly improving wear resistance, which is the objective of the present invention, cannot be obtained, and if it exceeds 2.0 wt%, the effective magnetic permeability becomes too low to be of practical use.

Adding C to Centast alloys significantly improves wear resistance, but tends to deteriorate mechanical workability and increase processing costs; however, by carburizing the core after machining, this machining Decrease in sexual ability is also improved.

EXAMPLES Below, in order to clarify the effects of the alloy of the present invention, it will be explained using examples.

Example 1 In Table 1, the metal used is 99.9% electrolytic iron, 99.999%
Silicon, 99.99% aluminum and Fe-4.3
10-4 Tor in an aluminum crucible using %C master alloy
Fe-Si-Al-C cast by high frequency melting in a vacuum of r
An ingot of the alloy was soaked in a vacuum at 1000° C. for 24 hours, and a sample of 8×11×13n square was cut out and the tape sliding surface was ground to IOR using a No. 2000 GC grindstone to obtain a wear sample piece.

The amount of wear, effective magnetic permeability and saturation magnetic flux density at 1KH2 of this worn sample piece against the magnetic recording cassette tape are shown in the table.

The tape used was D-C90 (product name) manufactured by TDK.
A wear test was conducted for 1000 hours in an environment with a temperature of 30° C. and a humidity of 75%.

As is clear from the results of Samples 1 to 8 in Table 1, it can be seen that when the C content is 0.01% or more, the wear resistance is significantly improved. Si. If the amount of C added is increased while the amount of Al is kept constant, the decrease in μe is remarkable, but as seen in samples black 9 to 10 in Table 1, when the amount of C added is increased, Si, A1
It can be seen that the smaller the amount, the higher μe becomes.

Example 2 In Table 2, 0.26 x 3 x 3 mI was obtained from ingots of Fe-Si-A1 alloys with various compositions that were vacuum melted and cast.
A corner TR head wear test piece was cut out, and the tape sliding surface was ground to 3R with a No. 2000 GC grindstone.The wear test piece was ground with a mixing ratio of argon, oxygen, and propane gas of 8:2:1.
, 4:1:1 and 4:1:2 and introduced into a carburizing furnace with the gas transformed in a nickel catalyst at 1000°C and carburized at 900°C for 2 hours to reduce the C content to 0.1, 0.5, 1.0wt
% alloys were used as samples.

These samples were tested at a temperature of 30°C on a videotape recorder.
Table 2 shows the results of a 100-hour abrasion test conducted at 75% humidity and the effective magnetic permeability and saturation magnetic flux density at 1 KHz and 1 MHz.

The wear amount is Si. It can be seen that the amount of C decreases significantly when the C content is large, almost regardless of the Al content. It can be seen that when the amount of carburization is large, the effective magnetic permeability at 1 kHz is higher when the amount of Si and A1 is smaller, and the effective magnetic permeability at 1 MHz is highest when the effective magnetic permeability at 1 kHz is about 6000.

By carburizing the center core chip in this way, the wear resistance can be significantly improved regardless of the grindability.

Claims (1)

[Claims] 1 Si4-11wt%, Al3-8wt%, C0.0
A wear-resistant, high magnetic permeability, high saturation magnetic flux density alloy consisting of 1 to 2.0 wt%, the balance being Fe.