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| GRINDING BERYLLIUM COPPER |
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The beryllium copper alloys can undergo rough, precision, surface, cylindrical, centerless and internal grinding. However,
it is important to note that the hardness of the beryllium copper alloys classifies them with the tougher alloys.
Standard abrasives, such as aluminum oxide and silicon carbide, are acceptable for most operations. While harder abrasives are usually unnecessary, they can be used successfully. In either instance, both bonded wheel
and coated belt configurations can he employed using either V (Vitrified) or B (Resinoid) bond type.
All grinding operations involving the beryllium copper alloys should be undertaken wet with copious coolant to provide cooling, remove swarf and limit the potential for airborne particulate. In this regard, water-based lubricants are recommended and additives, such as defoamers or rust-inhibiters, present no difficulty. While petroleum-based, mineral oil and synthetic lubricants can also be employed, they offer no advantage over water-based lubricants.
The recommended tool configurations are shown in Figure 7. Speeds and feeds, for both surface (cylindrical) and centerless grinding, are shown in Tables 6 and 7. It is important to note that the beryllium copper alloys grind up to 100% faster than steel. Unlike brass and aluminum, these alloys pose no clogging problems with the use of high structure, porous belts and wheels. |
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GRINDING TOOL CONFIGURATION - FIGURE
7 |
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Surface grinding wrought and cast beryllium copper - Table 6 |
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| MATERIAL | ROCKWELL HARDNESS | WHEEL SPEED (ft./min.) | WORK SPEED (ft./min.) | INFEED ON DIA. (in./pass) | TRAVERSE WHEEL WIDTH (per rev of work) | WHEEL IDENTIFICATION* ANSI & ISO |
| A, H High Strength All Tempers High Conductivity |
B20-100 | 5500 to 6500 | 70 to 100 | Rough: .002 Finish: .0005 max. |
1/3 1/6 |
C46JV |
| AT, HT High Strength | C34-45 | 5500 to 6500 | 70 to 100 | Rough: .002 Finish: .0005 max. |
1/3 1/6 |
A54LV |
| * Wheel recommendations are for wet grinding at 2 to 4 inch [50 to 100mm] diameter work. For DRY grinding - use a softer grade wheel. For LARGER diameter work - use a softer and/or coarser grit wheel. For SMALLER diameter work - use a harder grade wheel. Wheel recommendations also apply to plunge grinding applications. | ||||||
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Centerless grinding wrought and cast beryllium copper - Table 7 |
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| MATERIAL | ROCKWELL HARDNESS | WHEEL SPEED (ft./min.) | THRUFEED OF WORK* (ft./min.) | INFEED ON DIA. (in./pass) | WHEEL IDENTIFICATION** ANSI & ISO |
| A, H High Strength All Tempers High Conductivity |
B20-100 | 5500 to 6500 | 50 to 150 | Rough: .005 Finish: .0015 max. |
C54KV |
| AT, HT High Strength | C34-45 | 5500 to 6500 | 50 to 150 | Rough: .005 Finish: .0015 max. |
A60LV |
| *As recommended starting
conditions - use a regulating wheel angle with a positive inclination of
3° and a regulating wheel speed of 25 to 40 rpm. **Wheel recommendations are for wet grinding 0.8 to 2 inch [20 to 50 mm] diameter work - use a softer grade and/or coarser grit wheel. For SMALLER diameter work - use a harder grade wheel. |
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