Method for manufacturing magnetic head using boronizing treatment

Claim 1

A method for manufacturing a magnetic head assembly from components including a permalloy magnetic shielding case having a surface portion thereof adapted to be brought into sliding contact with a magnetic recording medium, said method comprising the steps of contacting said surface portion with a powdered boronizer comprising boron carbide, heating said permalloy shielding case including the surface portion thereof which has been contacted with said powdered boronizer in the temperature range between 950° C. and 1100° C. in a hydrogen atmosphere to magnetically anneal said permalloy shielding case and simultaneously convert said surface portion to a wear-resistant boronized layer, and lowering the temperature of said case including said boronized layer at a rate corresponding to a temperature lowering rate for magnetically annealing said permalloy shielding case.

Claim 2

A method for manufacturing a magnetic head assembly from components including a permalloy magnetic shielding case having a surface portion thereof adapted to be brought into sliding contact with a magnetic recording medium, said method comprising the steps of contacting said surface portion with a powdered boronizer comprising boron carbide, heating said permalloy shielding case including the surface portion thereof which has been contacted with said powdered boronizer in the temperature range between 950° C. and 1100° C. in a hydrogen atmosphere to magnetically anneal said permalloy shielding case and simultaneously convert said surface portion to a wear-resistant boronized layer, and lowering the temperature of said case including said boronized layer at a rate corresponding to a temperature lowering rate for magnetically annealing said permalloy shielding case.

Claim 4

A method of manufacturing a magnetic head assembly including a permalloy core and shielding case wherein said core and shielding case have surfaces adapted to be brought into contact with a magnetic recording medium, said method comprising the steps of contacting at least one of said surfaces with a powdered boronizer, heating in a hydrogen atmosphere said core and shielding case including the surface thereof which has been contacted with said powdered boronizer in the temperature range between 950° C. and 1100° C. to magnetically anneal said permalloy core and shielding case and simultaneously form a boronized layer having a thickness greater than 200 μm,

Claim 5

A method of manufacturing a magnetic head assembly including a permalloy core and shielding case wherein said core and shielding case have surfaces adapted to be brought into contact with a magnetic recording medium, said method comprising the steps of contacting at least one of said surfaces with a powdered boronizer, heating in a hydrogen atmosphere said core and shielding case including the surface thereof which has been contacted with said powdered boronizer in the temperature range between 950° C. and 1100° C. to magnetically anneal said permalloy core and shielding case and simultaneously form a boronized layer having a thickness greater than 200 μm,

Claim 8

A method of manufacturing a magnetic head assembly including a core and a shielding case wherein said core and shielding case have surface portions adapted to be brought into contact with a magnetic recording medium, at least one of said core and shielding case being made of an Fe-Ni magnetic alloy, said method comprising the steps of contacting at least one of said surface portions with a powdered boronizer, heating in a hydrogen atmosphere in the temperature range between 950° C. and 1100° C. said core and shielding case including the surface portion thereof which has been contacted with said powdered boronizer to magnetically anneal said Fe-Ni magnetic alloy and simultaneously convert said surface portion to a boronized layer having a thickness greater than 200 μm thereby effecting a solid boronizing treatment, lowering the temperature of said core and shielding case including said boronized layer at a rate corresponding to a temperature lowering rate for magnetically annealing said core and shielding case, and grinding each surface on which said boronized layer has been formed, said boronized surface having a Vicker's hardness not greater than 1500 kg/mm 2 , a wear resistance substantially greater than that of non-boronized permalloy and a smoothness which permits a magnetic recording medium to slide smoothly thereon.

Claim 9

A method of manufacturing a magnetic head assembly including a core and a shielding case wherein said core and shielding case have surface portions adapted to be brought into contact with a magnetic recording medium, at least one of said core and shielding case being made of an Fe-Ni magnetic alloy, said method comprising the steps of contacting at least one of said surface portions with a powdered boronizer, heating in a hydrogen atmosphere in the temperature range between 950° C. and 1100° C. said core and shielding case including the surface portion thereof which has been contacted with said powdered boronizer to magnetically anneal said Fe-Ni magnetic alloy and simultaneously convert said surface portion to a boronized layer having a thickness greater than 200 μm thereby effecting a solid boronizing treatment, lowering the temperature of said core and shielding case including said boronized layer at a rate corresponding to a temperature lowering rate for magnetically annealing said core and shielding case, and grinding each surface on which said boronized layer has been formed, said boronized surface having a Vicker's hardness not greater than 1500 kg/mm 2 , a wear resistance substantially greater than that of non-boronized permalloy and a smoothness which permits a magnetic recording medium to slide smoothly thereon.

Claim 11

A method of manufacturing a magnetic head assembly including a core and a shielding case wherein said core and shielding case have surface portions adapted to be brought into contact with a magnetic recording medium, at least one of said core and shielding case being made of an Fe-Ni magnetic alloy, said method comprising the steps of contacting at least one of said surface portions with a powdered boronizer, heating in a hydrogen atmosphere in the temperature range between 950° C. and 1000° C. said core and shielding case including the surface portion thereof which has been contacted with said powdered boronizer to magnetically anneal said Fe-Ni magnetic alloy and simultaneously convert said surface portion to a boronized layer having a thickness greater than 200 μm thereby effecting a solid boronizing treatment, and lowering the temperature of said core and shielding case including said boronized layer at a rate corresponding to a temperature lowering rate for magnetically annealing said core and shielding core, and grinding each surface on which said boronized layer has been formed, said boronized surface having a Vicker's hardness not greater than 1500 kg/mm 2 , a wear resistance substantially greater than that of non-boronized permalloy and a smoothness which permits a magnetic recording medium to slide smoothly thereon.

Claim 12

A method of manufacturing a magnetic head assembly including a core and a shielding case wherein said core and shielding case have surface portions adapted to be brought into contact with a magnetic recording medium, at least one of said core and shielding case being made of an Fe-Ni magnetic alloy, said method comprising the steps of contacting at least one of said surface portions with a powdered boronizer, heating in a hydrogen atmosphere in the temperature range between 950° C. and 1000° C. said core and shielding case including the surface portion thereof which has been contacted with said powdered boronizer to magnetically anneal said Fe-Ni magnetic alloy and simultaneously convert said surface portion to a boronized layer having a thickness greater than 200 μm thereby effecting a solid boronizing treatment, and lowering the temperature of said core and shielding case including said boronized layer at a rate corresponding to a temperature lowering rate for magnetically annealing said core and shielding core, and grinding each surface on which said boronized layer has been formed, said boronized surface having a Vicker's hardness not greater than 1500 kg/mm 2 , a wear resistance substantially greater than that of non-boronized permalloy and a smoothness which permits a magnetic recording medium to slide smoothly thereon.