Here’s a fact that’ll get the attention of manufacturers. Simply by adopting a Powder Metallurgy operation, great economic savings become feasible. Remember, there’s less machining to be done after a PM produced component has been manufactured, so the finance department can zero out machine shop costs. It’s the same with finishing, with this phase of the work now surplus to requirement. In fact, end-line pressed and sintered products are practically ready for packing.
An Energy Saving Manufacturing Method
It takes exorbitant amounts of thermal energy to turn raw alloy bars into molten metal. Huge castings receive the orange-hot melted alloy. Alternatively, special sand-cast cavities take the place of the hardened metal castings. Again, massive amounts of heat make this process possible. The energy melts solid steel or aluminium to the point that they liquefy. Well, Powder Metallurgy equipment simply doesn’t need that much thermal energy. No, as long as the Green compact is hot enough to sinter, then the metal grains will coalesce. That’s “coalesce,” not melt. Incidentally, it takes time to cool moulded metal products. That extended cooling period is not part of the PM process.
The Process Step Reduction Advantage
Back at a forging and machining operation, the metal is melted, then it’s poured into a group of moulds, then it’s left to cool, then there’s the ejection phase to implement. With all of that done, all of the “then” stages submitted and completed, are the castings finished? They are not finished, not quite yet. There’s still the machining and finishing work to be done. Perhaps the dimensions of a cast component have expanded because of the heat. A milling machine shaves off the excess surface material. It’s an inconsequential quantity of surplus material, yet it can’t be left like that, not on a high-tolerance parts manufacturing line. That’s an additional finishing stage, one that’ll ramp up the cost of the process. Performed without utilizing vast quantities of dimension skewing heat, Powder Metallurgy work typically produces fully finished end-line products.
PM manufacturing is clearly the economically viable victor. There are no molten metals to generate, so the process doesn’t require tremendous quantities of heat. Sintering heat triggers particle coalescence action, which doesn’t necessitate forging energy levels. And without that liquefaction heat, an end-line product comes off of a Powder Metallurgy output station as a dimensionally stable part. Not so with a similarly specified casting. It’s been exposed to chaotic heating and cooling forces. On being ejected from their moulds, there’s still the form and surface correcting machining to be done, which sucks more costs from a number of machining operations.