The increased use of turbochargers has become an important trend in car manufacturing. This trend has been driven by requirements to design smaller, more powerful engines that also reduce fuel consumption.
Modern vehicles contain hundreds of electric control units (ECUs). These control functions that range from operation of the engine to keyless entry. An ECU receives input from the vehicle then communicates with an actuator to perform a specific action. For example, a door lock ECU would activate an actuator to unlock or lock a door. OEMs and manufacturers are introducing more ECUs into vehicles to meet demands in features and performance.
A major benefit to manufacturing with powder metal is that parts are made to near net shape. Often, machining is thus only a secondary operation for improving shape precision and surface quality.
Like most manufacturing processes, porosity is inherent to powder metallurgy. Porosity is only considered a defect if it is interconnected and creates a leak path can affect the part’s structural integrity and performance. This blog discusses the four main reasons why vacuum impregnation is used to seal powder metallurgy leak paths.
If the leak paths are not sealed, then fluids or gases may leak from the part. Vacuum impregnation prevents fluids or gases from leaking by sealing the porosity and leak paths. The process does this without changing the powder metal component’s dimensional or functional characteristics
Plating operations submerge the parts in acid solutions. The residual acid can seep into the porosity, which causes corrosion. Sealing the components before plating eliminates the risk of internal corrosion.
Secondary machine operations, such as drilling, tapping, or cutting, are impaired as the voids between the particles cause tool chatter, reducing tool life and finish quality. Vacuum impregnation stabilizes and supports the individual powdered metal granules during machining. This improves machinability by making it more efficient, eliminating tool chatter, and improving the machined finish.
Powder metal porosity absorbs oils, fluids, deburring fluids, pre-plating cleaners, and acids. If not sealed, fluids may bleed out and negatively affect the finish. Sealing the porosity before secondary finishes will eliminate any failure mode that could develop from bleed out of pretreatments.
Vacuum impregnation adds value to powdered metal components. The process eliminates failure modes caused by porosity, produces pressure tight parts, improves machinability, and meets surface finish/appearance requirements.
