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Apex Advanced Technologies, Inc. Presented by: Dennis Hammond

Apex Advanced Technologies, Inc. Presented by: Dennis Hammond. Optimizing Lubrication To Maximize Density and Minimize Ejection Forces. Presentation Outline. Overview of Superlube ™ characteristics Theory of maximizing density and minimizing ejection forces

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Apex Advanced Technologies, Inc. Presented by: Dennis Hammond

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  1. Apex Advanced Technologies, Inc.Presented by: Dennis Hammond Optimizing Lubrication To Maximize Density and Minimize Ejection Forces

  2. Presentation Outline • Overview of Superlube™ characteristics • Theory of maximizing density and minimizing ejection forces • Methods used to optimize lubrication • Applications • Minimizing ejection for large or complicated parts at a G.D. of 7.0 g/cc • Maximizing density and minimizing ejection forces for pure iron and performance alloys • Conclusions

  3. Superlube™ Characteristics • Lubricant enters with the powdered metal as a solid, transforms from a solid to a viscous liquid with shear, temperature, and pressure in the press • Lubricant shear thins directly with shear stress • Direct results from solid to liquid transformation • High density achievable, 7.2 to 7.4 g/cc • Low use levels required, typical 0.4% or less • Excellent lubricity, film of viscous liquid versus slide on a solid particle

  4. Direct results • No special setup required • Stroke rate can be increased • Compressibility curve can be modified to allow larger parts or lower tonnage in the same press • Tool wear improved due to better lubrication and/or lowering of tonnage • Surface finish improved • Improved physical properties of final part by 15 - 20%

  5. Direct Results Cont. • Powder movement to equalize green density, near hydrostatic conditions in compact • Minimization of density gradients in the part • Elimination of micro cracking • Reduces the risk of molding cracks • Staggered decomposition in burn off • Excellent dimensional stability of sintered parts

  6. Theory of Optimization • Maximum green density is fixed by the compressibility of the base metal, volume of components added, and TSI • Excellent lubrication allows the user to approach the maximum green density for a composition at a given TSI applied

  7. Theory Cont. • Using an internal Apex method, we can determine the maximum practical green density of a base metal at a given TSI • Theoretical density minus practical density = volume of open space • By targeting to fill this open space with the volume of the components in the mix, we have a basis for calculation of total volume % achieved

  8. Maximum Compressibility of Various Base Metals

  9. Maximum Compressibilityof Various Base Metals

  10. Maximum Compressibilityof Various Base Metals

  11. Theory Cont. • Mobile lubricant is pressed to the die wall due to the collapse of the pores or closing of the open space as the base metal is compressed • Serves as an internal and die wall lubricant at the same time

  12. Theory Cont. • 98% to 100% volume fill has been found to work effectively • 99%to 99.5% volume fill is an optimum target to achieve max. green density and minimum ejection while accommodating normal production variability • Predictability is robust and has been proven in many production examples

  13. FLN2-4405 TSI/ G.D./ Vol.%.35% Superlube™

  14. Theory Cont. • Some formulas need to have the volume adjusted upward to take maximum advantage of the lubricant • An Apex enhancer can be used effectively to make volume adjustments • Key issues are, the volume contribution of components needed and the desired density

  15. Common Formulation for FN-0205

  16. Common Formulations Calculated G/D,TSI, A-1000C,.35% Superlube™ • FN-0205: • 99% vol. 7.31g/cc, 46 TSI • 100%vol. 7.39g/cc, 52 TSI • FN-0208: • 99% vol. 7.23 g/cc, 41TSI • 100% vol. 7.30 g/cc, 45TSI • FC-0208: • 99% vol. 7.21 g/cc, 41TSI • 100% vol. 7.29 g/cc, 45TSI

  17. Enhancer Characteristics • Clean burning, no ash • Primary function to fill space, secondary lubrication • Needs to deform and slide with the metal and lubricant movement • Helps to maintain green strength • Compatible with mixing, compaction and processing • Favorable cost, specific gravity ratio

  18. Applications • A tall or complex part of lower G.D. - 6.9 to 7.1 g/cc can be made successfully by adjusting the volume fill upward by using an enhancer. • Benefits include lowering ejection forces, minimized die wear, part breakage, internal cracking or lower compaction tonnage to achieve the desired G.D.

  19. Applications cont. • A pure iron part can be made using the same concept, 98-100% volume fill pressed to the desired TSI • A-1000C was filled with a combination of Superlube™ and Apex Enhancer at various volume %, ejection (peak and slip) were measured as well as density • Possible applications - magnetic parts, etc

  20. A-1000C Comparison Acrawax versus Apex 60TSI

  21. High Density Applications • High density parts can be made by using the lubricant alone or with small amounts of enhancer • Many applications are running in production at 7.2 - 7.4 g/cc • Lubricant use level ranges from 0.27% to 0.45% for steel parts

  22. High Density Applications Cont. • FC-0208 NAH ABC 100.30, 0.4 wt% lube, 9# part, 54 mm height, 7.2 g/cc, 45 TSI, 99.3%volume, lowered press TSI • FC-0208 NAH ABC 100.30, 0.4% lube, 40 mm height, 51 mm O.D. 7.3 g/cc, 55 TSI 99.9% volume, large part, high density

  23. High Density Applications Cont. • FLC-4608, A-737SH, 0.45 wt% lube, 50 mm height, 51mm O.D. gear, 7.2 g/cc, 51TSI, 99.4% volume, large part, high density • Astaloy Mo, 2% Ni, 0.3% Graphite, 0.35% lube, 0.15% enhancer, 20 mm height, 7.27 g/cc, 49TSI, multi-level with hole 99.0% volume fill

  24. High Density Applications Cont. • FLN2-4405, A-85HP 0.35% lube 7.29 - 7.33 g/cc, 49-52TSI, 6mm - 51mm height, 14 applications helical gear, straight gears, multi- level parts, counter bores, ~99-99.4% volume fill • A-85HP,2% nickel, 0.35% lube, .25% graphite,0.15% enhancer, 7.3 g/cc, 51TSI, 25 mm height, gear, 99.5% volume fill, elimination of double press

  25. High Density Applications Above Target Range • Excellent Lubricity with .25-.4% • High Density 7.25 g/cc and above • Metal restricted from maximum compressibility • Reduced hydrostatic effect • Predictability of density achievable but TSI predictions are difficult • Formulas with 3% additions and higher are most likely to be over 100% fill

  26. Application Summary • High Density 7.2 - 7.4 g/cc • Elimination of double press, double sinter • Highly efficient, cost effective copper infiltration • Elimination of cracks, parts 6.9-7.4 g/cc • Minimization of ejection problems, 6.9-7.4 g/cc • Minimization of die wear,6.9-7.4 g/cc • Improved part performance and surface finish • High nickel based parts without blistering

  27. Lube and Density Prediction • By knowing the compressibility of the metal involved, the components, the part length, size, and the desired density, we can calculate the lube or enhancer needed • From this calculation, achievable density verses TSI can be predicted • Predictability has been robust and a very viable tool for optimizing, new part development, and problem solving

  28. Conclusions • Maximum density and minimum ejection forces are not exclusive to each other, they can be obtained at the same time • A lubricant that transforms from a solid to liquid changes the rules compared to conventional lubricants • Compressibility of the base metals varies significantly, and it is a critical factor in the results achievable

  29. Conclusions Cont. • High density 7.2 - 7.4 g/cc can be achieved with no special equipment or procedures with good ejection characteristics • Lower density can be successfully made with lower tonnage, lower ejection forces, and good green strength • Desired lubrication and density are predictable using developed calculation methods

  30. Conclusions Cont. • We can approach the upper compressibility limit for the base metal at a given TSI with alloy components included • By designing a lubricant system for a given application, the breadth of parts that can be made can vary from small to large, moderate to high density, and simple to complex. • Theory and practice are transferable to other P/M parts Al, Brass,Bronze, and S.S.

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