Ancordense

ANCORDENSE Technical Publications

198. High Density via Single Pressing / Single Sintering High density processing via single press / single sinter processing enables powder metallurgy processing of ferrous materials to be both more cost efficient and produce higher performance components. Obtaining high densities via single press / single sintering necessitates a systems approach to preparation of the starting powder premix and subsequent compaction and sintering. This paper will describe a powder and processing method that facilitates single press-single sintered densities approaching 7.5 g/cm³. At this sintered density, the mechanical properties of the P/M component are significantly improved over existing compaction techniques and begin to approach the performance of wrought steel.

190. Segregation-free Premixes for Increased Productivity and Improved Performance Powder mixes used in the P/M industry contain ingredients of substantially different particle sizes and specific gravities that have a strong tendency to segregate during handling. Reducing or eliminating this segregation is essential for the part producer to achieve consistent precision and optimum performance. Treating the premixes with polymer binders helped to resolve this problem. Binder/lubricant systems have been developed that provide improved flow rates combined with increased green densities and green strengths. A review of these developments will be presented and their impact on overall productivity and performance will be outlined.

150. The Effect of Processing and Density on PM Soft Magnetic Properties With the trend towards more widespread use of automotive electric systems such as electric power steering, new opportunities exist for P/M soft magnetic alloys. These applications require high density for magnetic properties and precision. To meet density, precision and geometry complexity requirements, secondary operations are usually employed, which degrade magnetic properties. Annealing can be utilized for recovery of the magnetic properties, but with the potential for dimensional changes. Through the use of an advanced binder system, higher densities with subsequent increases in magnetic properties can be achieved in a single compaction step. The influence of secondary operations, processing methods such as the use of an advanced binder system and annealing are presented for Fe, Fe-P and Fe-Ni materials.

112. Processing of Hybrid Alloys to High Densities Premixes containing prealloy molybdenum, such as Ancorsteel 85HP, nickel and graphite have exceptional mechanical properties. This presentation will highlight the properties of these materials processed to densities of 7.25 to 7.45 g/cm³ by single press, single sinter techniques. The exceptional green strength of these materials in combination with density provides a unique opportunity to convert more automotive components to P/M.

91. Engineered Approach to High Density Forming using Internal and External Lubricants. The drive to obtain higher densities, strength and dynamic properties in P/M has prompted the development of methods, including Double Press / Double Sinter, Copper Infiltration, Warm Compaction etc., to achieve these goals. One of the contributing factors influencing higher densities is the addition of lubricant to the premix. With advances in lubricant technology and binder-treated premixes it is possible to achieve higher density parts, with reduction of internal lubricant and die wall lubrication This study combines the effects of using a balance of internal and external lubrication to improve the properties of P/M materials.

90. Advanced Processing of Sinter-Hardening Materials The sinter-hardening process has been shown to provide excellent mechanical properties and part-to-part size control. Previous work has indicated that exceptional mechanical properties and high apparent hardness values can be achieved by sinter hardening in a high temperature furnace with standard cooling. This work focuses on combinations of advanced techniques intended to optimize mechanical properties for stringent applications. While warm compaction is utilized to increase density, various material alloy combinations are blended together in an effort to study green density variables. Where applicable, specific market opportunities are identified.

82. New Higher Performance Materials Through the use of enhanced atomization, annealing, and binder treatment technologies, several new silicon-containing alloy grades have been introduced for high performance automotive applications. This presentation will include data on compacts produced from these new grades using conventional compaction, warm compaction, and double press / double sinter processing. With these new material systems, single compaction can achieve ultimate and yield strengths in excess of 1200 MPa and 800 MPa with elongation over 2%. Such tensile properties can be developed in conjunction with apparent hardness values over 65 HRA and impact energies exceeding 25 Joules.

81. Opportunities for Conversion of Powertrain Components from Malleable/Ductile Cast Irons to Powder Metallurgy Malleable and ductile cast irons are used extensively in gearing and high strength applications within automotive power train applications. Advantages of malleable and ductile cast irons are low material cost with mechanical properties that meet or exceed the requirements of the intended application(s). One disadvantage of the malleable cast iron is the extensive heat treating required to obtain the proper microstructure and mechanical properties. Both malleable and ductile iron components require extensive machining to produce the finished component. The combination of heat treating and extensive machining often results in a component that is costly to manufacture. Recent advances in the Powder Metallurgy (P/M) process including high strength material systems and high density processing have achieved mechanical properties that meet or exceed the level achieved with the current malleable and ductile cast iron materials. This paper will present an evaluation and comparison of the mechanical properties of malleable cast iron with selected P/M material systems and processing parameters. This property discussion will demonstrate the suitability of the P/M process in replacing these cast and machined components. Examples of specific parts will be cited and discussed.

80. Application of Sinter-Hardenable Materials for Advanced Automotive Applications such as Gears, Cams, and Sprockets Recent demands within the automotive industry have been for applications requiring high hardness, high hardenability, and increased mechanical performance. These often conflicting requirements necessitated the development of new materials that offer high as-sintered hardness and good static/dynamic mechanical properties without the added expense of a secondary heat treatment. Traditionally, sinter-hardening materials have offered acceptable hardness but at the expense of mechanical properties and sintered density. This paper will document a series of sinter hardening materials that offer good compressibility, high hardness and enhanced mechanical properties. The discussion will focus on utilization of these materials in automotive applications (within both the engine and transmission) such as gears, cams and sprockets that are currently produced by either the press, sinter, and heat treat process or by conventional machining of a casting or wrought material.

67. A Comparison of ANCORDENSE Processed Materials with Malleable Cast Iron A study was conducted that compared the mechanical properties of a series of ANCORDENSE prepared materials with malleable cast iron. This paper will present the mechanical properties (TRS, tensile, impact, and fatigue) of various ANCORDENSE prepared premixes in the as sintered condition compared with a malleable cast iron. The objective of this investigation was to demonstrate that an engineered P/M material coupled with ANCORDENSE processing can replace a malleable cast iron component giving equivalent mechanical property performance and potentially equivalent gear performance.

65. Ancorloy Premixes: Binder Treated Analogs of the Diffusion Alloyed Steels The properties at two carbon levels of binder treated analogs of the diffusion alloyed steels are presented. These Ancorloy premixes are made according to a proprietary practice that does not include diffusion alloying. It is shown by direct comparison with compositionally similar premixes of the diffusion alloyed steels that the Ancorloys generally exhibit similar powder, green and dimensional change properties and significantly enhanced mechanical properties. Tensile, impact and fatigue property data in the sintered, sintered and tempered and quenched and tempered conditions are presented.

57. Application of High Performance Binder-Treated Materials Binder treated materials such as ANCORBOND^® and ANCORDENSE^® increase the performance characteristics of ferrous powder premixes and P/M parts. This paper will discuss the various characteristics of binder treated premixes and their potential applications. A review of the mechanical properties of ANCORDENSE materials will be presented.

53. The Application of Warm Compaction to High Density Powder Metallurgy Parts The warm compaction process (ANCORDENSE^®) has been shown to provide increased density in ferrous powder metallurgy parts. This improvement in density contributes significantly to mechanical properties and thus the overall performance of the part. The combination of increased density with high performance material selections, provides parts that can exceed the performance of forged or cast material counterparts while taking advantage of powder metallurgy's net shape forming capabilities.

Turbine hubs for automatic transmission torque converters have proven to be ideal candidates for the powder metallurgy (P/M) process. The complex shape of turbine hubs is costly to produce via conventional forging and machining operations. However, increases in engine size and torque requirements in several automotive designs have required that turbine hubs possess higher levels of mechanical properties. High density P/M manufacturing techniques, in combination with high performance ferrous materials produces components capable of replacing a forged and machined turbine hub.

This paper will review the conversion of a conventionally forged and machined turbine hub used in a high torque automatic transmission to a single pressed and single sintered P/M turbine hub. The material used for the P/M hub was an FD-0405. This diffusion alloyed material was evaluated in the laboratory and mechanical properties are reported at several density levels. Warm compaction processing achieved high overall sintered densities in the highly stressed internal spline region. Extensive mechanical and part specific testing was conducted to verify the suitability of the P/M part.

49. The Effect of Nickel Content, Sintering Temperature, and Density on the Properties of a 0.85 w/o Molybdenum Prealloy The combination of molybdenum prealloyed steel powders and admixed nickel provides sintered steels that are used in structural parts requiring strength, wear resistance, and impact toughness. The properties of these materials, like all P/M steels, are dependent on density, microstructure and composition. This work discusses the effect of admixed nickel content, sintering temperature, and density on the properties of a 0.85 w/o molybdenum prealloy. Samples were prepared with 0, 2, 4 and 6 w/o nickel additions. The materials were warm compacted at 30, 40, 45, and 50 tsi (415, 550, 620 and 690 MPa) and sintered at 1900°F, 2100°F and 2300°F (1040°C, 1150°C, and 1260°C). Mechanical properties were determined and related to the density, microstructure, and composition.

47. The Manufacture of Electromagnetic Components by the Powder Metallurgy Process The powder metallurgy process provides the ability to manufacture net shape parts from a variety of materials in a cost effective manner. A market segment that has exhibited the ability to take advantage of powder metallurgy's flexibility has been in electromagnetic applications. This area has shown significant growth in the past decade that should continue for the foreseeable future.

This paper will discuss materials and processes that have proven successful in several electromagnetic applications. Both sintered materials for DC type applications and insulated materials for AC applications will be reviewed along with appropriate processing techniques for each. Specific applications for both materials will be presented.

46. Recent Applications of Binder Treatment Technology The development of a practical binder treatment process in the late 1980's has since led to the commercialization of several new premix technologies that have had a major impact on P/M competitiveness. To date, a great deal has been written about these technologies. However, until now, there has been little to suggest that they are inherently interrelated by a common approach, or that this approach has untapped potential for still newer and better technologies. In addition, it also happens that in spite of all that has been written on the existing technologies, there is nothing that serves as a comprehensive single source of information on all of them. Consequently, the purpose of the present paper is to document the indicated approach as well as to present a summary description of each of the technologies complete with one or more production case histories of recent origin. The aim of the latter is to present discriminating up-to-date examples of general interest as well as to highlight one or more of the various advantages of the associated technology.

43. Single Compaction to Achieve High Density in Ferrous P/M Materials in Automotive Applications The continued growth of ferrous powder metallurgy in automotive applications is dependent on the development of higher density and improved dynamic properties. New powder metallurgy applications also must be cost effective through the continued use of the process's, net shape forming capabilities and a reduced number of manufacturing steps. The processes utilized to manufacture some of these new parts also must provide the ability to produce thin walled parts with complex geometries.

The use of the warm compaction process (ANCORDENSE™) will be shown to develop high density levels with a single compaction process. The process also provides increased green strength and reduced ejection forces. The dependence of mechanical properties on density will be demonstrated.

An example of a potential application of the warm compaction technology is an output shaft. The capability of manufacturing this part with the warm compaction process is outlined and compared with the same part made by the double press/double sinter (DPDS) process. Part density and performance from both processes are compared.

42. The Effect of Microstructure on Fatigue Properties of High Density Ferrous Materials Fatigue testing (rotating bending fatigue) has been performed on several high performance ferrous P/M material systems. Detailed metallographic analysis was performed to determine differences in the failure mechanisms for various material and process combinations. A variety of material compositions were single compacted to high density via the ANCORDENSE™ compaction system. This was followed by conventional and high temperature sintering and testing in the as-sintered and heat treated conditions. The analysis provides information as to the relationships between density, structure and composition with fatigue life.

41. Properties of Several ANCORDENSE Processed High Performance Materials The effect of powder and compaction temperature on the ANCORDENSE™ warm compaction system is evaluated. Detailed property analysis is presented on several warm compacted high performance materials systems. Properties evaluated include density, tensile, and impact performance. A detailed assessment of the microstructure resulting from various alloy compositions and processing techniques is performed. The materials involved in the tests were conventional and high temperature sintered and tested in the as sintered and heat treated condition.

38. Powder Metallurgy Gears - Expanding Opportunities Powder metallurgy (P/M) is a precision metal forming technology for the manufacturing of parts to net, or near net shape. The powder metallurgy process is illustrated schematically in Figure 11. There are three basic steps to producing parts; mixing, compacting, and sintering. Variations to these basic steps such as infiltration, double pressing/double sintering, and powder forging may be used to achieve higher density parts. A sizing operation may be used to qualify critical part dimensions. Alternatively, a machining step may be added for the same purpose or to achieve a geometric feature not possible during rigid die compaction. P/M parts may be through hardened or surface hardened as required by the intended application.

36. Powder Metallurgy in Electromagnetic Applications New product and process advances have expanded the potential for powder metallurgy growth into a variety of new applications. The ANCORDENSE™ process has enabled high density powder metallurgy parts to be attained cost effectively. Increases in density improve the magnetic performance of powder mettallurgy materials. In addition, a new process for producing iron powder with a then thermoplastic coating has been developed. Compacts produced from this material exhibit excellent high frequency magnetic properties. The role that these advances in powder metallurgy play in electromegnetic applications is discussed.

34. Machinability Evaluation of Selected High Green Strength P/M Materials P/M parts generally require machining methods and specific tools designed to address the inherent porosity of the finished part. The composition and microstructure of sintered parts often causes machining problems and requires additives to enhance machinability. Currently, conventionally produced ferrous P/M parts have an average green strength of approximately 1500-psi. Recent technological advances with organic binders and lubricants, combined with improved compaction technology, have made it possible to produce P/M parts with enhanced green strengths. Enhanced green strength makes it possible to machine materials in the green state, thereby reducing manufacturing time and production costs. This paper examines green drilling by applying several machinability and material evaluation methods.

33. An Investigation Into the Effects of Processing Methods on the Mechanical Characteristics of High Performance Ferrous P/M Materials The mechanical properties of high performance ferrous P/M materials are influenced by the material composition and processing method. This paper investigates the effects of the ANCORDENSE™ process, a new, high density, single compaction method, on the mechanical properties of Distaloy® 4800A based materials. The results of this study are discussed with a comparison to the mechanical properties for the same materials developed through single-pressed and double-pressed, doublesintered processing methods. In addition, a case study is performed on a component produced via the ANCORDENSE method.

32. Properties of Diffusion Bonded Alloys Processed to High Densities Diffusion bonded alloys have been shown to exhibit excellent properties. Recent advancements in compaction technology have allowed these materials to reach green density levels of over 7.3 g/cm³ in a single compaction process. Various capabilities of this new compaction system will be demonstrated utilizing diffusion bonded alloys. Properties of several diffusion bonded materials will be investigated at these high density levels. A variety of processing techniques will be utilized including high temperature sintering and heat treatment to demonstrate the flexibility of these materials.

31. Advanced Properties of High Density Ferrous Powder Metallurgy Materials The introduction of the ANCORDENSE™ system has provided significantly higher density levels than previously possible in a single press/single sinter operation. This paper will explore the role that higher density has on mechanical properties. Various properties will be evaluated, including transverse rupture strength, tensile strength, and impact. Additionally, the effect of other processes, such as high temperature sintering and heat treatment, will be addressed.

27. Recent Developments in Ferrous Powder Metallurgy Alloys A systems approach to engineered ferrous powder metallurgy (P/M) materials is described. The approach encompasses the use of high compressible, high performance powders in premixes produced using proprietary mixing technology that employs patented binders. To ensure that an appropriate microstructure is achieved to suit the functional requirements of a particular application, alloys are formulated based on knowledge of the compaction and sintering cycle that will be used to make the P/M parts. These premixes have improved flow and die filling characteristics that result in greater consistency throughout the entire P/M part manufacturing process. In addition, the use of binder treated premixes leads to reduced dusting and segregation of alloy additions. Binder treated premixes produced using high compressible, prealloyed molybdenum steel powders are shown to be particularly well suited for quench-hardening, sinter-hardening, and high temperature sintering. They also form the basis for a series of chromium, manganese, and chrome-manganese P/M 'Steels. The systems approach will be augmented during 1994 by the introduction of new material and process technology that enables part densities of 7.3 to 7.5 g/cm3 to be achieved through single compaction processing.

24. Properties of High Density Ferrous P/M Materials, A Study of Various Processes Several methods of achieving higher density in ferrous P/M parts are possible. Double press/double sinter allows densities in excess of 7.3 g/cm3 but is limited by cost and geometry considerations. A new method of single processing high performance materials is evaluated and compared to other methods of processing. The comparison is performed utilizing Ancorsteel 85HP and Distaloy 4800A base materials. Various green and sintered properties are evaluated including; green strength, transverse rupture strength, tensile properties and impact values.

The data clearly demonstrates that the patented (1) ANCORDENSE™* process offers performance comparable to double press/double sinter processing. Green density values of approximately 98.5% of the pore free density limit are achieved with a single compaction step.

23. High Density Processing of High Performance Ferrous Materials Density is an predominant factor in the performance of powder metallurgy components. Methods such as double press/double sinter, copper infiltration and powder forging have been employed to provide higher densities than traditional single press and sinter operations; however, their widespread use is constrained by cost and geometry considerations.

A commercially proven method for obtaining single compaction/single sinter densities in the 7.25 to 7.55 g/cm³ range by means of the patented ANCORDENSE™ technology is introduced. Conventional compaction pressures and sintering temperatures, typically not exceeding 50 tsi or 2300°F, respectively, are utilized. Resulting properties for several high performance materials are presented.

Test results indicate that the ANCORDENSE process is a cost effective method of providing high density parts with outstanding physical properties. The process is shown to be applicable to a wide variety of high performance materials. Additionally, significant improvements in green strength and ejection forces are realized.

22. High Density Processing of CR-Mn P/M Steels The use of chromium and manganese as alloying elements in P/M steels offers several potential advantages over copper and nickel that are used in conventional P/M alloy steels. The paper will illustrate how the principles used to improve the hardenability and performance of wrought steels can be applied to P/M chromium and manganese alloy steels using a systems approach. The use of chromium-manganese for P/M applications was made possible by binder-treated premix technology of a highly compressible prealloyed low alloy base material. The flexibility of alloy design will be illustrated by examples of through hardening, high strength low alloy steels.

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