The low-temperature brazing process for diamond saw blades represents a revolutionary high-end manufacturing technology, fundamentally transforming the traditional 'grinding' principle of saw blades towards true 'cutting'.
The low-temperature brazing process for diamond saw blades is a precision technique employing specialised brazing materials containing active elements. At relatively low temperatures, each diamond particle is "welded" onto the saw blade substrate through robust chemical bonds.
1. Definition of Low-Temperature Brazing Process
Low-temperature brazing constitutes a 'chemical metallurgical bond', centred on the utilisation of reactive brazing alloys. During heating, reactive elements within the alloy-such as titanium, chromium, or vanadium-react chemically with carbon atoms on the diamond surface, forming a robust carbide layer. This carbide layer acts as a 'bridge', chemically bonding to the diamond at one end while integrating into the brazing alloy at the other, ultimately achieving an atomic-level strong connection between the diamond, brazing material, and steel substrate.
The 'low temperature' in low-temperature brazing refers to the reduced heating requirements compared to the 900–1100°C demanded by traditional hot-press sintering. Brazing temperatures typically range between 700°C and 900°C. This temperature ensures both the melting of the brazing filler and the progression of chemical reactions, while minimising the risk of diamond undergoing graphitisation at elevated temperatures. This critical control preserves the diamond's inherent strength.
2. Comparison of Low-Temperature Brazing and Hot-Press Sintering Processes
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Hot-Press Sintered Saw Blades |
Low-Temperature Brazed Saw Blades |
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Fixing Method |
Mechanical setting, akin to encasing a cluster of pebbles (diamonds) within cement (matrix), relying on the cement's contraction upon setting to grip the stones. |
Chemical welding, akin to using a powerful welding torch (active flux) to firmly weld the bases of individual spikes (diamonds) onto the steel plate. |
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Working Configuration |
Random grinding, with diamonds distributed haphazardly and only partially exposed. During operation, it resembles grinding material with a blunt tool. |
Orderly cutting, with diamonds arranged in an orderly fashion and highly exposed. During operation, it functions like sharp teeth performing continuous cutting. |
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Diamond State |
Embedded within the matrix, with low exposure height (approximately 30-50%). |
Projecting above the substrate, with extremely high exposure height (up to 70-80%). |
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Failure Mode |
After matrix wear, the entire diamond detaches (regardless of whether it has become blunt). |
The diamond remains firmly held until it is completely worn away. |
