The porous structure is one of the characteristics that makes powder metallurgical parts so widely used, but the high porosity makes them more difficult to machine.
Firstly, porosity causes the cutting edge to be unwearable. The cutting edge passes between the grain and the hole as it cuts in and out, and the repeated small impacts lead to the creation of small cracks on the cutting edge which continue to grow until the cutting edge is slightly chipped. Secondly, the inherent porous structure causes an increase in surface area, which allows oxidation or carbonisation to occur during heat treatment, forming oxides and carbides that are hard and wear resistant. Once again, the high temperature of the cutting edge causes wear and deformation of the insert. Finally, due to the presence of pores, there are fluctuations in hardness values over a smaller area, and the hard particles involved in the workpiece can lead to severe and sharp edge wear.
When machining large quantities of powder metallurgy workpieces, tool breakage or rapid wear can disrupt the rhythm of machining and thus reduce productivity; when surface finishing large powder metallurgy workpieces, changing tools midway can affect the quality and efficiency of machining. Obviously, choosing a more suitable tool material for powder metallurgy workpieces can reduce processing costs, improve processing efficiency and further guarantee the quality of the processed parts.
Not only do the surfaces machined by WSS tools meet the needs of our customers, but WSS tools also show a high cost performance compared to the competition. In addition, WSS also offers a tool resharpening service for its customers, further reducing the cost of machining for manufacturers.
Tool drawing number: 071071/070961
Workpiece name: intake/exhaust valve guide
Workpiece material: powder metallurgy
Material hardness: HRB50~70
Workpiece diameter: φ11
Roughness：Ra1.6
Machining method: Turning, internal cooling
Machining process: Finishing
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| 071071 170 pieces 070961 170 pieces | |
At the same time, WSS PCD tools can also be used to machine powder metallurgy valve guides, offering customers the option to address their different machining needs.
PCD machining of powder metallurgy valve guides
Workpiece name: Valve guide
Workpiece material: powder metallurgy
Workpiece diameter: φ6
Machining method: Fine reaming
Vc（m/min）: 30
f（mm/min）: 280
Tool life: 2450
