20th to 23rd October 2009

 

MACOR® Machinable Glass Ceramic Machinable with ordinary metalworking tools & combining the performance of a technical ceramic with the versatility of a high performance plastic.

Precision Ceramics is a Macor Distributor. Precision Ceramics is a Macor Expert. In fact, there is no other Macor Supplier who knows more about this unique machinable glass ceramic than Precision Ceramics. We're also experts in Macor Metallization and publishers of the Macor Technical Bulletin.

Macor is an outstanding engineering material and is machinable with ordinary metalworking tools. Macor is also a problem solving material combining the performance of a technical ceramic with the versatility of a high performance plastic.

Macor has a high use temperature (800°C continuous to 1,000°C peak). It has a low thermal conductivity and is a useful high temperature insulator as well as an excellent electrical insulator. Macor has no porosity and when properly baked out, will not outgas. It is strong and rigid and, unlike high temperature plastics, will not creep or deform. Macor is also radiation resistant.

Macor is pure white and can be highly polished. It can be thick or thin film metallised, brazed and epoxy bonded. Another major advantage of this unique material is that, even in small quantities, components are economical to manufacture.

Macor Machining

Key factors for successful machining are proper machining speeds and coolant. Macor machinable glass ceramic can be machined with high speed tools, but carbide tools are strongly recommended for longer wear and better finishes. Be generous with coolants. As with any new material, it is well worthwhile taking some time to learn how Macor behaves during machining.

Achieve the best results by using a water-soluble coolant especially formulated for cutting and grinding glass or ceramics. No post firing is required after machining.

Setting Up

When machining small or delicate pieces, make sure that clamping the load is uniformly distributed. Use soft jaws if at all possible.

Sawing

Use a carbide grit blade at a band speed of 100 fpm (30.5m/min). An alternative is a silicon carbide or diamond cut-off wheel.

Turning

Using carbide tooling:

• Cutting speed = 9-15 m/min (30-50 sfm)

• Feed Rate = 0.005-0.013 cm/rev (.002-.005 ipr)

• Depth of cut = 0.38-0.65 cm(.150-.200 in)

Milling

Using carbide tooling:

• Cutting speed = 6.1-10.7 m/min (230-35 sfm)

• Feed Rate = 0.05mm per tooth (.0025 ipt)

• Depth of cut = 0.38-0.51 cm(.150-.200 in)

Drilling

Tapping

Make a clearance/pilot holes one size larger than those recommended for metals. Chamfer both ends of the hole to reduce chipping. Run the tap in one direction only. Turning the tap back and forth can cause the chipping.

Continuously flush with water or coolant to clear chips and dust from the tap.

Grinding

Diamond, silicon-carbide or aluminium oxide grinding wheels can be used.

Polishing

Start with loose 400-grit silicon carbide on a steel wheel. For the final polish, use cerium oxide or alumina on a polishing pad for glass ceramics. A 0.013µm (0.5µin) finish can be achieved.

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