HOEGANAES INSULATED POWDER COMPOSITES CHARACTERISTICS AND ELECTROMAGNETIC APPLICATION GUIDELINES

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1 HOEGANAES INSULATED POWDER COMPOSITES CHARACTERISTICS AND ELECTROMAGNETIC APPLICATION GUIDELINES

2 HOEGANAES INSULATED POWDER COMPOSITES INTRODUCTION The molecular field theory was developed nearly years ago. At that time, it was explained that groups of iron atoms are magnetized in one direction with equal groups of atoms magnetized in the opposite direction, thus fully compensating each other with zero net magnetic moment. These groups of atoms are referred to as magnetic domains. In a given iron powder particle, there are a substantial number of domains all arranged in a way to give a zero magnetic moment. Extremely fine particles can potentially represent single domain structures. Lodestone happens to be a natural, single domain iron ore (magnetite), which exhibits intrinsic permanent magnet characteristics. Its discovery had a significant impact on the history of the world. The development of Insulated Powder Composites represents the next step toward further advancement in soft magnetic material systems! BENEFITS OF THE POWDER METALLURGY PROCESS Net Shape Capability Complex Shapes Engineered Materials High Production Rates Tolerance Control Good Surface Finish BENEFITS OF INSULATED POWDER MATERIALS Isotropic magnetic structure permits 3-dimensional magnetic flux path capability Easily shaped into complex configurations using conventional powder metallurgy compaction process Similar magnetic saturation induction values to wrought steel laminations Low inherent eddy current losses associated with the dielectric polymer coating Flexibility to engineer performance characteristics to satisfy application requirements Preferred alternative to laminations for new electric motor designs

APPLICATIONS CHART For switching actuators and ignition coils, fuel injectors, motor applications Resistivity Strength Induction B Permeability micro- (MPa) ka/m (T) Max ohm-meter Ancorlam >5 9.

3 APPLICATIONS CHART For switching actuators and ignition coils, fuel injectors, motor applications Resistivity Strength Induction B Permeability micro- (MPa) ka/m (T) Max ohm-meter Ancorlam > Ancorlam HR > Ancorlam 2HR* > For higher frequency applications, power electronics Resistivity Strength Induction B Permeability micro- (MPa) ka/m (T) Max ohm-meter Ancorlam 2FHR > Ancorlam HR > For motor applications requiring high induction and permeability, actuators, frequencies up to 4 Hz Resistivity Strength Induction B Permeability micro- (MPa) ka/m (T) Max ohm-meter Ancorlam Ancorlam 2HR* *Density of 7.6 g/cm 3 Grade modification is possible to meet application specific properties POWDER METALLURGY PROCESSES FOR ELECTROMAGNETIC GRADES Composite Production: Admix Metal Powder, Additives, Coating Materials Press Ready Insulated Powder Composite Material Cold or Warm Compaction Optional Secondary Curing or Stress Relieving Optional Finishing Processes: Machining Polymer Impregnation Plating Finished Electromagnetic Component CONVERSIONS / CALCULATIONS Tesla = Gauss X -4 Tesla = Weber per meter 2 Gauss = Maxwell per cm 2 Amp-Turns per meter = Oersteds x 79.5 ( Amp-Turn per meter =.25 Oe) Tesla/Meter Gauss x.26-6 = Amp-Turns Oersted Frequency = Inductance = rpm x Number of Poles (rotating electrical devices) 2 L = 4πµA N 2 I L = Inductance (mh) µ = Permeability A = Cross-sectional area (cm 2 ) I = Path length (cm) N = Number of turns µm Microstructure illustrating insulative coating

HOEGANAES INSULATED POWDER COMPOSITES Iron powders exposed to a magnetic field gradually begin to realign the individual domains by slowly orienting themselves toward the direction of the applied

4 HOEGANAES INSULATED POWDER COMPOSITES Iron powders exposed to a magnetic field gradually begin to realign the individual domains by slowly orienting themselves toward the direction of the applied magnetic field. When the magnetic field is switched off, the domains remain partially oriented in the original magnetic direction. Zero magnetism is realized when the reverse field equals the coercive force. With further increases in the reverse field, the domains revert to the new direction. The field required to reverse the domain depends upon the crystalline symmetry and anisotropic properties. This energy is very small in the case of a soft magnetic material, and considerably greater for a hard magnetic material, i.e., types that maintain high remanence, typically referred to as permanent magnets. The most commonly used soft magnetic material involves electrical steel laminations for low frequency (6 2 Hz) applications. Low-end performance materials include cold-rolled, motor lamination steels, whereas intermediate to high-end characteristics are achieved with silicon-iron, or oriented steels. Laminations are prevalent because of existing design familiarity, relatively low costs and adequate magnetic performance. Nevertheless, the limited two-dimensional flux path capability and relatively low energy efficiency at higher operating frequency make them undesirable for new electric motor designs. INSULATED POWDER COMPOSITES The introduction of uniformly coated iron particles providing a three-dimensional distributed air gap with an isotropic flux path, allows designers to reconsider conventional topology restrictions typical of steel laminations. Along with the benefits of PM net shape manufacturing capability, insulated composite materials exhibit inherently low eddy current losses even when subjected to operating frequencies exceeding 4 Hz. Composite manufacturing flexibility provides the ability to engineer soft magnetic characteristics to suit specific application requirements. Incorporating different iron powder size distributions, and coating types to increase resistivity, various attributes can be manipulated to enhance the material s permeability, structural density or core-loss characteristics. Coupling new electrical device design topologies with insulated powder composites and high-energy permanent magnets provides the necessary performance enhancements along with concurrent improvements in component efficiency, packaging and simplified manufacturing processes. The additional magnetizing force (mmf) of the permanent magnet compensates for the lower permeability of the soft magnetic composite grades. The complementary materials and new designs provide greater performance and enhanced efficiency, with the ability to reduce manufacturing costs and component package size. Applications for these magnetic materials include high-efficiency electric motors, high-frequency transformers, and unique electrical components. The electrical design engineer has three-dimensional shape-making flexibility plus the high material utilization inherent with the PM process. Design flexibility is enhanced further by the ability to bond together small segments to form larger, more complex shapes.

5 INSULATED POWDER COMPOSITE PERFORMANCE AncorLam AncorLam HR AncorLam 2 HR AncorLam 2F HR AncorLam 2 Compacting pressure (MPa) Powder temp. ( o C) RT RT RT RT RT Tool temp. ( o C) Curing temp. ( o C) >3 >3 >3 >3 >3 Cured density Induction ka/m (T) Permeability at Resistivity, micro-ohm-meter >5 >3 >5 >3 >5 Coercive field strength (A/m) Strength (MPa) T (watts/kg) Hz Hz Hz Hz All properties improve with higher compaction pressures(density), especially induction, permeability and core-loss. Insulated Powder Composite manufacturing flexibility provides the ability to engineer soft magnetic characteristics to suit specific application requirements. Incorporating different iron powder size distributions and coating types to increase bulk resistivity various attributes can be manipulated to enhance the material s structural density, induction, permeability or core-loss characteristics. Grade modification is possible to meet application specific properties.

6 AncorLam AncorLam is a high performance insulated powder material suitable for a variety of soft magnetic applications. Specific applications include switching actuators and ignition coils, fuel injectors, and motor applications. AncorLam consists of high purity iron powder with a specialized coating/lubricant system that minimizes hysteresis and eddy current losses over a range of frequencies. This material is provided as a press-ready premix for warm or cold die compaction. AncorLam is a lower cost option giving good balance between Core Loss and Induction. Performance of AncorLam at 7.45 g/cm 3 Induction at 4 ka/m (T).9 Induction at ka/m (T).47 Maximum permeability 47 Coercive field strength (A/m) 3 Core-loss at 4 Hz, T, W/kg 67 Core-loss khz, T, W/kg Green density (g/cm 3 ) 7.47 Cured strength (MPa) 9 Resistivity micro-ohm-meter >5 Apparent density (g/cm 3 ) Hall flow (s/5 g) 32 max HYSTERESIS LOOP AncorLam Applied Field in A/m

7 AncorLam (continued) CORE-LOSS VS. INDUCTION, Hz, 2 Hz, 4 Hz, k Hz, 5k Hz, khz Core-loss in Watts/kg. khz khz 5 khz khz 4 Hz 2 Hz Hz PERMEABILITY VS. INDUCTION, FREQUENCY, Hz, 2 Hz, 4 Hz, Hz, 5 Hz 45 4 Core-loss in Watts/kg Hz

8 AncorLam HR AncorLam HR has a constant permeability over a wide frequency range providing a lower cost option for high frequency applications. AncorLam HR consists of high purity iron powder with a specialized coating/lubricant system that minimizes hysteresis and eddy current losses over a range of frequencies. This material is provided as a press ready premix for warm or cold die compaction. Performance of AncorLam HR at 7.45 g/cm 3 Induction at 4 ka/m (T).9 Induction at ka/m (T).52 Maximum permeability 37 Coercive field strength (A/m) 27 Core-loss at 4 Hz, T, W/kg 53 Core-loss khz, T, W/kg 47 Green density (g/cm 3 ) 7.45 Cured strength (MPa) 6 Resistivity micro-ohm-meter >3 Apparent density (g/cm 3 ) Hall flow (s/5 g) 32 max HYSTERESIS LOOP AncorLam HR Applied Field in A/m

9 AncorLam HR (continued) Core-loss in Watts/kg.. CORE-LOSS AT VARIOUS FREQUENCIES AND INDUCTION, Hz, 2 Hz, 4 Hz, Hz, 5 Hz, Hz khz 5 khz khz 4 Hz 2 Hz Hz PERMEABILITY AT VARIOUS FREQUENCIES, Hz, 2 Hz, 4 Hz, Hz, 5 Hz, Hz 35 3 Hz Permeability

10 AncorLam 2HR AncorLam 2 HR is bested suited for motor and actuator applications. Providing good induction and permeability for applications up to HZ. AncorLam 2 HR consists of high purity iron powder with a specialized coating/lubricant system that increase permeability while limiting losses. This material is provided as a press ready premix for warm or cold die compaction. Performance of AncorLam 2HR Induction at 4 ka/m (T) 2.2* Induction at ka/m (T).64* Maximum permeability 6* Coercive field strength (A/m) 246* Core-loss at 4 Hz, T, W/kg 52* Core-loss khz, T, W/kg 72* Green density (g/cm 3 ) 7.6* Cured strength (MPa) 9* Resistivity micro-ohm-meter >475* Apparent density (g/cm 3 ) * Hall flow (s/5 g) 32 max* * Density is 7.6 g.cm 3 HYSTERESIS LOOP AncorLam 2HR*(7.6 DENSITY) Applied Field in A/m

11 AncorLam 2HR (continued) CORE-LOSS VS INDUCTION (7.6 DENSITY), Hz, 2 Hz, 4 Hz, Hz, 5 Hz, Hz khz 5 khz khz 4 Hz 2 Hz Hz Core-loss in Watts/kg PERMEABILITY VS INDUCTION (7.6 DENSITY), Hz, 4 Hz, Hz, 5 Hz, Hz 6 5 Permeability khz

12 AncorLam 2FHR AncorLam 2FHR is targeted and engineered for higher frequency applications up to 3 Khz. AncorLam 2FHR consists of high purity iron powder with a specialized coating/lubricant system that minimizes hysteresis and eddy current losses over a range of frequencies. This material is provided as a press ready premix for warm or cold die compaction. Performance of Ancorlam 2FHR at 7.45 g/cm 3 Induction at 4 ka/m (T).9 Induction at ka/m (T).5 Maximum permeability 36 Coercive field strength (A/m) 3 Core-loss at 4Hz, T, W/kg 54 Core-loss khz, T, W/kg 46 Green density (g/cm 3 ) 7.43 Cured strength (MPa) 6 Resistivity micro-ohm-meter >3 Apparent density (g/cm 3 ) Hall flow (s/5 g) 32 max HYSTERESIS LOOP AncorLam 2FHR Applied Field in A/m

13 AncorLam 2FHR (continued) Core-loss in Watts/kg.. CORE-LOSS AT VARIOUS FREQUENCIES, Hz, 2 Hz, 4 Hz, Hz, 5 Hz, Hz khz 5 khz khz 4 Hz 2 Hz Hz PERMEABILITY AT VARIOUS FREQUENCIES AND INDUCTION, Hz, 2 Hz, 4 Hz, Hz, 5 Hz, Hz 35 3 Hz Permeability

14 AncorLam 2 AncorLam 2 is a high performance insulated powder material suitable for a variety of soft magnetic applications that require high permeability. Used for applications up to 4 HZ. Performance of AncorLam 2 at 7.45 g/cm 3 Induction at 4 ka/m (T).95 Induction at ka/m (T).6 Maximum permeability 55 Coercive field strength (A/m) 245 Core-loss at 4 Hz, T, W/kg 67 Core-loss khz, T, W/kg 245 Green density (g/cm 3 ) 7.49 Cured strength (MPa) 4 Resistivity micro-ohm-meter >5 Apparent density (g/cm 3 ) Hall flow (s/5 g) 32 max DC HYSTERESIS LOOP AncorLam Applied Field in A/m Applied Field in A/m

15 AncorLam 2 (continued) Core-loss in Watts/kg.. CORE-LOSS AT VARIOUS FREQUENCIES, Hz, 2 Hz, 4 Hz, Hz, 5 Hz, Hz khz 5 khz khz 4 Hz 2 Hz Hz AC PERMEABILITY, Hz, 2 Hz, 4 Hz, Hz, 5 Hz, Hz 5 4 Permeability 3 2 Hz

16 RELEVANCE OF MATERIAL CHARACTERISTICS ON END-USE PERFORMANCE FOR ELECTROMAGNETIC DEVICES Permeability Influences the output power of the electrical device. Wrought lamination stacks represent two-dimensional values typically ranging between 5 and 5, whereas the isotropic IP grades approach ~5 permeability. Some conversions may necessitate higher input current to achieve similar flux density. However, 3-dimensional flux paths provide greater design and performance flexibility. In addition, use of high-energy permanent magnet materials can compensate for the lower permeability of the soft magnetic composite grades. Induction Influences the ultimate torque capability of rotating machines. Lower values can be offset by increasing the backing section (material mass), while maintaining optimal component packaging associated with optimized end-winding and slot fill. Strength In some instances, components must withstand rotational forces, stresses associated with press fitting or compression joining, and have sufficient strength to accommodate the copper winding process during assembly. Appropriate polymer types and process conditions permit adequate strength to support application requirements. AC Frequency Preferred applications involve operating conditions of 2 Hz electrical frequency. This utilizes the benefits associated with the inherently low eddy current losses of I.P. materials. Core-Loss The two primary components of core-loss include eddy current and hysteresis losses. Greater core-loss values generally increase operating temperatures, which leads to additional losses. Lower loss values translate into greater electrical efficiencies. Losses can be minimized with proper particle coating, binder combinations and stress relief. Processing Conditions Various options exist depending upon the binder and/or lubricant combinations. Warm compaction, with or without powder heating, or conventional compaction can be used for a variety of applications. Base Iron Chemical composition and particle size, along with component density, can be manipulated to enhance specific magnetic performance characteristics. Curing Temperature A secondary thermal treatment enhances the binder strength and helps minimize internal stress promoting recovery of the iron powder crystal structure. Temperature optimization is required to limit internal stresses without destroying the binder characteristics.

MAGNETIC TERMINOLOGY Induction (B) is the magnetic flux per unit area, measured in Gauss. Sometimes referred to as flux density. This characteristic has a direct relationship with component density.

17 MAGNETIC TERMINOLOGY Induction (B) is the magnetic flux per unit area, measured in Gauss. Sometimes referred to as flux density. This characteristic has a direct relationship with component density. Permeability (µ) essentially indicates the ease with which a material can be magnetized or its magnetic sensitivity represents a ratio of flux density to magnetizing force. Coercive Field Strength (H c ) is the demagnetizing force necessary to restore the magnetic induction to zero. Eddy Current Loss is the primary component of high frequency loss. Generally associated with electrical currents that create an opposing force to the magnetic flux when exposed to AC fields. Higher resistivity values are beneficial in minimizing eddy current losses. Hysteresis Loss represents the primary loss factor at lower frequency, and is primarily attributed to magnetic friction in the core. Wider and taller B-H loop areas generally represent greater hysteresis loss for a given material. Intrinsic Saturation is the point at which all the domains in the magnetic material become oriented in the same direction as the applied field energy. Magnetizing Force (H) is the applied energy to induce magnetic flux, measured in Oersteds. Hysteresis Curve is the measurement technique representing the closed circuit of a magnetic material subjected to positive and negative magnetizing forces graphically represents the material s magnetic characterization, i.e., saturation, residual induction and coercive field strength. Soft Magnetic components have the ability to both store or strengthen magnetic energy and allow for easy conversion back into electrical energy - often utilized to strengthen the magnetic flux of an electric device as a core product. Hard Magnets represent greater coercivity levels and are difficult to demagnetize, typically referred to as permanent magnets and represent a broad B-H curve band-width (>M.M.F.). Air Gap represents a low permeability gap (air space) in the flux path of a magnetic circuit, generally undesirable for energy transfer however, can be beneficial to increase the ability to store energy in a core. Reluctance essentially represents magnetic circuit resistance, which is inversely proportional to permeability and directly proportional to magnetic circuit length. Ferrites are combinations of iron oxides with Mn, Zn, Ni used when high permeability and low eddy current losses are desirable, generally exhibit low saturation induction generally used for high frequency KHz to GHz applications. Laminations are low carbon steel or silicon-iron grades made in thin strips with insulation coating positioned between layered stacks, extensively used in low electric motor applications because of low cost and design familiarity. Iron Powder Cores share some characteristics with Insulated Powder grades. They are primarily used for energy storage, transformers and inductors in various consumer products. Q Factor is a means of determining the effectiveness of an iron core represents a ratio of the increase in effective inductance to the increase in the equivalent resistance of the magnetic circuit: Q = I / R (I= increase in test coil inductance, R = core-losses). Hysteresis curve representative of a soft magnet material

EFFECT OF CURING CONDITIONS ON PROPERTIES OF IRON-RESIN MATERIALS FOR LOW FREQUENCY AC MAGNETIC APPLICATIONS.

EFFECT OF CURING CONDITIONS ON PROPERTIES OF IRON-RESIN MATERIALS FOR LOW FREQUENCY AC MAGNETIC APPLICATIONS. C. Gélinas, F. Chagnon, S. Pelletier* and L.-P. Lefebvre*. Quebec Metal Powders Limited Tracy,