Ceramic Extrusion Dies Outperform Traditional Dies in both Direct and Indirect Presses
Magnesia Stabilized Zirconium Oxide Extrusion Dies, from Zircoa, Inc., are engineered to provide the high temperature stability, chemical inertness, hardness, wear and corrosion resistance, required to extrude non-ferrous alloys such as Copper, Copper-Nickel, Brass, and other Copper alloy shapes up to 152.4mm (6.0") OD.
Improve Results in Conventional Applications with Ceramic Extrusion Dies
Zirconia ceramic extrusion dies, from Zircoa, are frequently used with a direct press, in which the billet moves through the die. Our dies are equally successful in an indirect press, in which the die moves through the billet. When properly used, Zircoa ceramic extrusion dies will significantly reduce machine shop rework, and consistently out-perform traditional tool steel and stellite dies, as well as high strength nickel alloy dies of INCONEL®718.
Ceramic Extrusion Dies Suited to Your Special Needs
Zirconia extrusion dies can be manufactured in various shapes in addition to the standard round die. Current Zircoa customers also use hexagonal, square, rectangular and oval die shapes. Dies made by Zircoa are used to extrude non-ferrous alloys such as Copper, Copper-Nickel, Brass, and other Copper Alloys, in sizes from 2.54mm (0.10") ID to 152.4mm (6.0") OD.
Zircoa offers two compositions of zirconia. Each is blended to satisfy the specific requirements of the extrusion manufacturer.
2016 - Tube Extrusion, for OD’s up to 152.4mm (6.0") This composition is well-suited for tube dies. It is specifically formulated to enhance its resistance to thermal shock and improve its ability to stand-up to thermal cycling.
5027 - Rod and Shape Extrusion, for diameters up to 50.8mm (2.0") Dies made of this composition have the extra strength and toughness needed for high reduction ratio extrusion.
Optimizing Ceramic Extrusion Die Performance
Our partnering with extruders has shown there are four basic steps to a successful switch from metal dies to ceramics. They include:
1. Design— The ceramic die should be as close to the metal configuration as possible, with a moderate wall thickness, such as 12.5 mm for a tube die. The land length should be just long enough to form the desired shell or rod diameter.
2. Shrink Fit — A refractory tool steel, such as H13, is commonly used for the case. Zircoa sales engineers can recommend the amount of interference and provide guidance on how to shrink fit. We also offer the ceramic die and case assembly.
3. Processing Adjustments (Preheat) — Die and case can go directly into preheat following shrink fit, and should be allowed to preheat for one hour per 25.4mm (1.0") of assembly wall thickness. (Cycling) - With ceramic dies, fast press cycles are preferred. The objective is to prevent the ceramic from cooling down, without overheating the case.
4. Training — Understanding the difference between metal and ceramic dies is key to successful application of ceramic dies. To aid in this understanding, Zircoa provides training and trouble-shooting during start-up.
We are happy to discuss the complete details on switching from metal to ceramic dies. Please contact our application engineers for more information.
Typical Properties of Zircoa's Ceramic Extrusion Dies
|RT MOR-4Pt. Bend||psi||30,000||50,000|
|Young‘s Modulus||psi x 106||36||32|
|Weibull Modulus||- - -||14|
|Hardness - Rockwell||"A" scale||- - -||83|
|- Vickers HV10||GPa||5.9||7.46|
|CTE-RT to 600°C||x10-6 per °C||7.3||2.4|
|CTE-RT to 1000°C||x10-6 per °C||6.6||3.4|
|T.C. @ 800°C (CALC)||W/m-°K||1.86||1.86|
|Specific Heat @ 300° C||cal/gm°C||0.152||0.15|
|Electrical Resistivity @ 28°C||ohm-cm||>108||>108|
|Electrical Resistivity @ 1000°C||ohm-cm||410||200|