As manufacturing engineers in PM factory you will be plannin

As manufacturing engineers in PM factory you will be planning the manufacturing of two spur gears with the same geometry of 16 tooth of diametral pitch of 2 and 0.25 thickness. One gear is to be made using Alloyed steel powder and the other is made using Aluminum alloy powder. If the customer for the alloyed steel gear orders 1M gear/year while the customer for the Aluminum alloy gear orders 100K gear/year, then conduct a basic research and analysis to provide/estimate the following

what Secondary manufacturing processes (heat treating, sizing, forging, finishing, etc..) if needed.??

Solution

Powder metallurgy parts sintered to net shape after compaction typically contain a minimum of approximately 10% residual internal porosity in traditional press-and-sinter methods. With warm compaction, minimum residual porosity can be lowered to approximately 5%. Unlike wrought steels, where hardening response is controlled primarily by chemical composition and grain size, P/M hardenability is significantly influenced by this interconnecting porosity, which makes the structure permeable to gases and fluidsHowever, as the P/M components become more complex in shape, such as the typical multilevel parts in production today, variations in porosity from one level to another can cause significant distortion in the part upon heat treating, which can affect the function or fit of the part in an assembly. When this occurs, a finish machining operation is usually required, which detracts from the cost benefit of powder metallurgy. but in case of gears any other process may deteriorate the gear profile. so such heat treatment process and sizing is advisable but some finishing process such as treaming and surface finishing is permissible.