Method of flow forming a metal part
View Patent ↗A method of flow forming sintered metal parts. The first step is forming a round disk by conventional powder metal process. The disk can be a donut shape part with or without a flange on one side of its outer diameter. The disk can then be copper impregnated or used as is, depending on the requirements. The disk is placed in a spinner held in proper tooling and grooves are spun in its outer diameter. The spinning can be done with a finishing roller or by a pre-finishing roller, followed by a finishing roller. This process not only creates a part with great accuracy, it also densifies and eliminates the powder metal porosities on the surface layer by the pressures inserted in spinning.
1. A method of manufacturing comprising the steps of:
preparing a powder metal mixture;
putting the powder metal mixture into a die;
compressing the powder metal mixture to form a part;
removing the part from the die;
sintering the part by application of heat;
spinning the part with a rotating mandrel;
engaging the part with a roller while spinning the part;
flow forming the part with the roller solely by a radial movement of the roller; and
forming a multiple ribbed surface in the part.
2. The method as in claim 1 further comprising the step of flow forming an inside diameter surface of the part.
3. The method as in claim 1 , wherein the part comprises a multiple ribbed pulley.
4. The method as in claim 1 further comprising forming a grain structure oriented sibstantially parallel to a rib surface.
5. The method as in claim 1 , wherein the multiple ribbed surface of the part has a density close tO 100% of the solid material density of the powder metal mixture.
6. The method as in claim 1 , wherein the part further comprises an inertia in the range of approximately 8000 kg mn 2 to approximately 30,000 kg mm 2 .