Disc Pressing Die: Hardened Steel, the Bore Lapped Along the Stroke (Schumacher & Souden, 1944)

The die in which powder is pressed into a flat disc: a block of hardened steel with a round bore, and close-fitting plungers that press the powder in it. The bore is lapped with rouge along the stroke, so its last fine scratches run the way the disc comes out. Result: a die for pressing metal or ceramic powders into discs, at 5 to over 100 tons per square inch. Source: E. E. Schumacher and A. G. Souden, Some Aspects of Powder Metallurgy, Bell System Technical Journal 23 (1944), pp. 431-433 and 454-455. Unknown: the steel, the hardening, sizes and clearances. Picture drawn by Youblob.

上級者

Unknown

手順

Make the die and plungers

Make the die of steel with a round bore through it, and plungers that fit the bore closely; there must be some clearance between them. Make the bore about three times as deep as the disc will be thick. Light, fluffy powders need a deeper die and longer plungers. Ours: tool steel for the die, and a lathe to bore and turn. Not given: the steel, sizes, clearance, the plungers' metal.

このステップの材料:

工具鋼角棒1 die

不明な金属1 plungers

必要な工具:

金属旋盤

不明な寸法

Harden the die

Harden the die. For very abrasive powders, make the die of hard carbide or line it with carbide instead. Ours: a heat-treating oven and a quench. Not given: the hardening heat and quench.

必要な工具:

熱処理炉

焼き入れ桶

Lap the bore along the stroke

Polish the bore to a high finish by lapping with polishing rouge, moving the lap in the direction of the plunger stroke. The fine scratches that remain then run the way the pressed disc is pushed out, not across it.

必要な工具:

研磨用ルージュ

Press a disc

Fill the bore with powder and press it with the plungers in a mechanical or hydraulic press, at 5 to over 100 tons per square inch. The powder hardly flows sideways, and friction at the die wall makes the pressure uneven: a part that is long for its width may come out with a soft, less dense middle. Push the disc out along the bore.

必要な工具: