公开(公告)号：DE3473958D1

公开(公告)日：1988-10-13

申请号：DE3473958

申请日：1984-10-31

Applicant: IBM DEUTSCHLAND ,  IBM

Inventor： BANDARA UPOLI DR ,  HINKEL HOLGER DR ,  STEINER WERNER ,  TRIPPEL GERHARD DR

IPC: G11B5/708 ,  G11B5/712

Abstract: In a magnetic disc consisting of a magnetic layer comprising a binder, magnetic particles, e.g. gamma-Fe2O3, and particles of an abrasion-resistant material, on a substrate, the abrasion-resistant particles are encased in a layer which reinforces the bonding to the binder. Pref. the dia. of the abrasion-resistant particles (I) is considerably less than the thickness of the magnetic layer. (I) consist of a hard ceramic, pref. Al2O3, SiC or Si nitride, and the encasing layer is of SiO2/Al2O3; or (I) may be a hard oxide, e.g. Al2O3, with OH gps. on the particle surfaces, and the encasing layer is of 'Teflon' (RTM). The 'Teflon' casing may be bonded chemically to (I) through a siloxane bridge and opt. an initiator residue, and to the binder, consisting of an epoxy resin, a polyurethane or a melamine resin, through an amine bridge.

公开(公告)号：DE3176223D1

公开(公告)日：1987-07-02

申请号：DE3176223

申请日：1981-08-05

Applicant: IBM DEUTSCHLAND ,  IBM

Inventor： BRUNSCH ARWED DR ,  RUH WOLF-DIETER ,  TRIPPEL GERHARD DR

IPC: G11B5/66 ,  G11B5/62 ,  G11B5/64 ,  G11B5/65 ,  G11B5/73 ,  G11B5/738 ,  G11B5/84 ,  H01F41/26

公开(公告)号：DE3162204D1

公开(公告)日：1984-03-22

申请号：DE3162204

申请日：1981-03-12

Applicant: IBM

Inventor： KIENLE HELMUT ,  SCHMID GERHARD E DR ,  STEINER WERNER ,  TRIPPEL GERHARD DR

IPC: G11B5/66 ,  C09D163/00 ,  G11B5/73 ,  G11B5/738 ,  G11B5/82 ,  G11B5/84 ,  G11B5/85 ,  G11B5/858 ,  H01F10/26 ,  H01F10/30 ,  H01R12/18

Abstract: Multi-layer magnetic thin film disks comprising a synthetic resin layer on an aluminum-containing substrate and an overlying metallic magnetic layer, are liable to have pin holes in the synthetic resin layer caused by galvanic corrosion of the aluminum in the substrate. The pin holes are passivated by aluminum oxide produced therein by anodically oxidizing the aluminum of the substrate in an electrolytic bath, the electric voltage of which is well below the normal passivation voltage for aluminum.

公开(公告)号：DE3014718A1

公开(公告)日：1981-10-22

申请号：DE3014718

申请日：1980-04-17

Applicant: IBM DEUTSCHLAND

Inventor： KIENLE HELMUT ,  SCHMID GERHARD DIPL PHYS DR ,  STEINER WERNER ,  TRIPPEL GERHARD DR

IPC: G11B5/66 ,  C09D163/00 ,  G11B5/73 ,  G11B5/738 ,  G11B5/82 ,  G11B5/84 ,  G11B5/85 ,  G11B5/858 ,  H01F10/26 ,  H01F10/30 ,  H01R12/18

Abstract: Multi-layer magnetic thin film disks comprising a synthetic resin layer on an aluminum-containing substrate and an overlying metallic magnetic layer, are liable to have pin holes in the synthetic resin layer caused by galvanic corrosion of the aluminum in the substrate. The pin holes are passivated by aluminum oxide produced therein by anodically oxidizing the aluminum of the substrate in an electrolytic bath, the electric voltage of which is well below the normal passivation voltage for aluminum.

公开(公告)号：DE2961717D1

公开(公告)日：1982-02-18

申请号：DE2961717

申请日：1979-10-31

Applicant: IBM

Inventor： TRIPPEL GERHARD DR ,  BRUNSCH ARWED DR ,  RUH WOLF-DIETER ,  SCHNEIDER JOCHEN

IPC: G01R33/18

Abstract: Direct method for measuring the magnetostriction constant lambda s of soft magnetic and isotropic magnetic materials. A thin film sample is cantilevered and clamped at one edge. Under the influence of a magnetic AC field and the magnetostriction effect of the sample material, the free end of the cantilevered sample is deflected and oscillates with twice the frequency of the AC field. The resonance amplitude ares is measured by using a laser beam impinging upon the oscillating sample and measuring the reflected beam amplitude by means of a position-sensitive photodiode. The AC output signal of the photodiode is proportional to the sample amplitude. The magnetostriction constant lambda s is directly proportional to the resonance amplitude ares multiplied by a constant factor which depends on known geometry and properties of the sample material.