公开(公告)号：DE1178763B

公开(公告)日：1964-09-24

申请号：DEJ0018996

申请日：1960-11-09

Applicant: IBM

Inventor： LEAYCRAFT EDGAR CRAWFORD

IPC: C04B35/26

Abstract: 887,632. Magnetic compositions. INTERNATIONAL BUSINESS MACHINES CORPORATION. Oct. 13, 1960 [Nov. 10, 1959], No. 35097/60. Drawings to Specification. Class 38 (2). In a process for the manufacture of magnetic cores having a square hysteresis loop and a coercivity between 1.1 oe. and 3.7 oe., which comprises the steps of mixing metal oxides including MnO and Fe 2 O 3 , calcining, pressing to form cores, and sintering, the values of Fe 2 O 3 particle size, calcining temperature, pressed density and sintering temperature are chosen to produce cores having a sintered density between 4.48 and 4.55 gm./c.c. The material may have a composition 38-44.4 mol. per cent Fe 2 O 3 , 55.1-60 mol. per cent MnO and 0-5 mol. per cent of (a) CuO or (b) CrO+NiO. The Fe 2 O 3 particles may have an average size of 0.6, 0.8 or 2.0 Á. A slurry, formed by wet ballmilling the oxides, is dried and ground and calcined in air for 30-180 minutes at a temperature between 750‹ C. and 950‹ C. The material is remilled, mixed with a binder and lubricant, moulded under pressure to form unsintered cores having a density 2.85-3.35 gm./c.c. and sintered at a temperature between 1100‹ C. and 1430‹ C.

公开(公告)号：DE3067705D1

公开(公告)日：1984-06-07

申请号：DE3067705

申请日：1980-10-15

Applicant: IBM

Inventor： LEAYCRAFT EDGAR CRAWFORD ,  OKTAY SEVGIN ,  OSTERGREN CARL DAVID

IPC: H05K7/20 ,  H01L23/367 ,  H01L23/467 ,  H01L23/46 ,  H01L23/36