Basket cases come into their own
Internal threads after thermally deburring
Thermal deburring can be one of the cheapest methods of deburring – up to 90% cheaper than electro-chemical methods - but it really comes into its own when components can be basket fired.
Thermal deburring also known as gas deburring, or it's more descriptive name, explosive deburring, sends a blast of extremely hot gas around and through the components. This blast wave can have pressures in the region of 2,000 bar with temperatures as high as 3,500 deg C. This very short (20 milliseconds) intense burst of heat oxidises the burrs but has negligible effects on the component, says Martin Bridges of Deburring Centre.
“Do you remember passing your hand quickly through a bunsen flame?,” he asks. “There was no effect on the skin but no hairs remained either!”
Normally large components like manifold blocks have enough mass to remain stationary during the blast. Smaller components will 'bounce' and need restraining with a fixture if dings and dents are an issue. However if surface damage is not an issue then components can be poured into a basket. It's then, by avoiding handling and fixturing each piece, that thermal comes into its own.
Thermal deburring is a non-selective process, guaranteeing the removal of all potential loose burrs.
Says Martin Bridges: “If it doesn't come off in the explosion it won't come off in service is the conclusion. As a rough guide, if you're components have no critical external features (like threads*) and can withstand being in a box dropped onto a concrete floor then they sound ideal components to reap the cost effectiveness of basket firing.”
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