Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/02—Alloys based on copper with tin as the next major constituent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D7/00—Casting ingots, e.g. from ferrous metals
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/04—Alloys based on copper with zinc as the next major constituent

Definitions

• Figure 1 is a table that includes the formulation of several known alloys based upon their registration with the Copper Development Association.
• the existing art for low lead or no lead copper based castings consists of two major categories: silicon based materials and bismuth/selenium materials.
• One embodiment of the invention relates to a semi-red brass having a composition of about 83% to about 91 % copper, about 0.1 % to about 0.8% sulfur, about 2.0% to about 4.0% tin, less than about 0.09% lead, about 4.0% to about 14.0% zinc, and about 1.0% to about 2.0% nickel.
• One embodiment of the invention relates to a tin bronze having a composition of about 8fi% In about 89% copper, about 0. 1 % to about 0.8% sulfur, about 7.5% to about 8.5% tin, less than 0.09%, lead, about 1 .0% to about 5.0%, zinc, and about 1 .0% nickel.
• Figure 1 provides Table 1 listing formulations for several known commercial copper alloys. [001 1 ]
• Figure 2 provides Table 2 listing formulations for Alloy Groups in accordance with embodiments of the present invention.
• Figure 3 A provides Table 3 listing alloy formulations for Group 1-A mechanical property examples by their respective casting heat.
• Figure 3B provides Table 4 listing the results of the average mechanical property testing of Group I-A by their respective casting heat.
• Figure 4A provides Table 5 listing alloy formulations for Group 1-B mechanical property examples by their respective casting heat.
• Figure 4B provides Table 6 listing the results of the average mechanical properly testing of Group I-B.
• Figure 5 A provides Table 7 listing alloy formulations for Group I I-A mechanical property examples by their respective casting heat.
• Figure 5B provides Table 8 listing the results of the average mechanical property testing of Group Il-A.
• Figure 6 provides Table 9 listing the typical and minimum properties observed for embodiments of certain Alloy Groups of the present invention and those properties reported for commercially available alloys such as those in Tabic 1 ( Figure 1).
• Figures 8A and 8B illustrate element mapping of sulfur in Alloy 1-A- 10a.
• Figure 9A is an SEM of Alloy I-A- 10; Figures 9B-H illustrate element mapping; Figure 9B is an EDS for Sn; Figure 9C is an EDS for Zn; Figure 9D is an EDS for Cu; Figure 9E is an EDS for Fe; Figure 9F is an EDS for Ni; Figure 9G is an EDS for P; Figure 9H is an EDS for S.
• Figure 1 OA is a micrograph of Alloy I-A- 10a, with regions 1 , 2, and 3 marked; Figures 10B-D show the presence of Cu2S, ZnS and Cu-Zn intermetallic phases: Figure 10B is an EDS spectra from region 1 ; Figure I OC is an EDS spectra from region 2; Figure 10D is an EDS spectra from region 3.
• Figures 1 1 A-B are optical images of Alloy I-A- 10a at low ( Figure 1 1 A) and high magnifications (Figure 1 1 B).
• Figure 12A is a SEM of alloy I-B- 10a and 12B illustrate element mapping of sulfur in Alloy I-B- 10 (0.31% S).
• Figure 13A is an SEM of Alloy I-B- 10a; Figures 13B-H illustrate element mapping at ! OOOx magnification; Figure 13B is an EDS for Sn; Figure 13C is an EDS for Zn; Figure 13D is an EDS for Cu; Figure 13E is an EDS for Fe; Figure 13F is an EDS for Ni; Figure 13G is an EDS for P; Figure 13H is an EDS for S.
• Figure 14A is an SEM of Alloy 1-B-l Ob; Figures 14B-H illustrate element mapping at 5000x magnification; Figure 14B is an EDS for Si; Figure 14C is an EDS for S; Figure 14D is an EDS for Fe; Figure 14E is an EDS for Cu; Figure 14F is an EDS for Zn; Figure 14G is an EDS for Sn: Figure 14H is an EDS for Pb; Figure 141 is an EDS for Ni.
• Figures 15A-B are optical images of Alloy l-B- 10 at low ( Figure 1 5A) and high magnifications (Figure 1 5B).
• Figures 16A and 16B illustrate element mapping of sulfur in Alloy Il-A- I 0a (0.30% S).
• Figure 17A is an SEM of Alloy 11-A-l Oa; Figures 17B-H illustrate clement mapping; Figure 17B is an EDS for Sn; Figure 17C is an EDS for Zn; Figure 17D is an EDS for Cu; Figure 17E is an EDS for Fe; Figure 17F is an EDS for Ni; Figure 17G is an EDS for P; Figure 17H is an EDS for S.
• Figure 1 8A is an SEM of Alloy lI-A-10b (0.19% S); Figures 1 8B-I illustrate element mapping al l OOOx magnification; Figure 1 8B is an EDS for Si; Figure 18C is an EDS for S; Figure 18D is an EDS for Fe; Figure 18E is an EDS for Cu; Figure 1 8F is an EDS for Zn; Figure 18G is an EDS for Sn; Figure 18H is an EDS for Pb; Figure 18 I is an EDS for Ni.
• Figures 19A-B are optical images of Alloy 1I-A at low ( Figure 19A) and high magnifications ( Figure 19B).
• Figures 20A and 20B illustrate element mapping of sulfur in Alloy ⁇ - ⁇ (0.01 1 % S).
• Figure 21 A is an SEM of Alloy III-A; Figures 21 B-H illustrate element mapping; Figure 2 I B is an EDS for Sn; Figure 21 C is an EDS for Zn; Figure 2 I D is an EDS for Cu; Figure 2 I E is an EDS for Fe; Figure 2 IF is an EDS for Ni; Figure 21 G is an EDS for P; Figure 21 H is an EDS for S.
• Figures 22A-B are optical images of Alloy III-A at low ( Figure 22A) and high magnifications ( Figure 22B).
• Figure 24 is a vertical section of different alloys in the Cu-Sn-Zn-S alloys
• Figure 25A is a phase distribution diagram of alloy I-A-l la using Scheil cooling
• Figure 25B is a magnified part of the phase distribution diagram showing the relative amounts of secondary phases.
• Figure 26A is a phase distribution diagram of alloy I-A- l l b using Scheil cooling.
• Figure 26B is a magnified part of the phase distribution diagram showing the relative amounts of secondary phases.
• Figure 27A is a phase distribution diagram of alloy I-A- l l c using Scheil cooling
• Figure 27B is a magnified part of the phase distribution diagram showing the relative amounts of secondary phases.
• Figure 28 A is a phase distribution diagram of alloy I-A-l I d using Scheil cooling
• Figure 28B is a magnified part of the phase distribution diagram showing the relative amounts of secondary phases.
• Figure 29A is a phase distribution diagram of alloy I-A- l le using Scheil cooling
• Figure 29B is a magnified part of the phase distribution diagram showing the relative amounts of secondary phases.
• Figure 30A is a phase distribution diagram of C83470 commercial alloy (Table 1 , Figure 1 ) using Scheil cooling
• Figure 30B is a magnified part of the phase distribution diagram showing the relative amounts of secondary phases.
• Figure 33 is a vertical Section of Group I-B.
• Figure 34A is a Scheil Phase assemblage diagram of Group I-B
• Fig, 34B is a magnified Scheil Phase assemblage diagram of Group I-B.
• Figure 35 is a vertical Section of Group II-A.
• Figure 36A is a Scheil Phase assemblage diagram of Group II-A
• Figure 36B is a magnified Scheil Phase assemblage diagram of Group II-A.
• Figure 37 is a graph of ultimate tensile strength (UTS) showing various heats of Alloy Group I-A compared to several known alloys, indicated by their CDA number.
• Figure 38 is a graph of yield strength showing various heats of Alloy Group I-A compared to several known alloys, indicated by their CDA number.
• Figure 39 is a graph of elongation showing various heats of Alloy Group I-A compared to several known alloys, indicated by their CDA number.
• Figure 40 is a graph of ultimate tensile strength (UTS) showing various heats of Alloy Group I-B compared to several known alloys, indicated by their CDA number.
• Figure 41 is a graph of yield strength showing various heats of Alloy Group I-B compared to several known alloys, indicated by their CDA number.
• Figure 42 is a graph of elongation showing various heats of Alloy Group 1-B compared to several known alloys, indicated by their CDA number.
• Figure 43 is a graph of ultimate tensile strength (UTS) showing various heats of Alloy Group II-A compared to several known alloys, indicated by their CDA number.
• Figure 44 is a graph of yield strength showing various heats of Alloy Group IJ-A compared to several known alloys, indicated by their CDA number.
• Figure 45 is a graph of elongation showing various heats of Alloy Group II-A compared to several known alloys, indicated by their CDA number.
• Figure 46A illustrates the sulfide particle sizes for a commercial sulfur brass, BiWaliteTM (C83470) and Figure 46B is photomicrograph showing particle size of Group 1- ⁇ alloy (.13 S - 4.45 Zn - 3.63 Sn).
• the invention relates to a composition of matter and methods for making same.
• the composition of matter is a copper-based alloy having a '"low' ' level of lead as would be understood by one of ordinary skill in the art of cavity devices that make contact with potable water, including, for example, plumbing fixtures.
• the level of lead is below that which are normally used to impart the beneficial properties to the alloy necessary for usefulness in most applications, such as tensile strength, elongation, machinability, and pressure tightness.
• Prior art no-lead alternatives to leaded brass typically require changes to the metal feeding for sand castings in order to produce sufficient pressure tightness (such as having no material porosity).
• the alloys of the present invention include particular amounts of sulfur, and in certain embodiments, the sulfur is added through a preferred method, to impart the beneficial properties lost by the reduction in lead.
• the alloys of the present invention relate generally to formulations of suitable semi-red brass, tin-bronze, and yellow brass. Certain embodiments are formulated for use primarily in sand cast applications, permanent mold cast applications, or wrought applications.
• Table 2 illustrates a group of alloys in accordance with the present invention.
• Each of the alloys is characterized, at least in part, by the relative low level of lead (about 0.09% or less) and the presence of sulfur (about 0.1 % to 0.8%).
• Three groups of semi-red brass, labeled Alloy Group I-A, Alloy Grovip 1-B, and Alloy Group 1-C are provided. In one embodiment, these semi-red brass alloys are suitable for sand casting.
• Three groups of tin bronze, labeled Alloy Group 1I-A, Alloy Group Il-B, and Alloy Group II-C are provided. In one embodiment, these tin bronze alloys are suitable for sand casting.
• Alloy Group ⁇ - ⁇ Six groups of yellow brass, labeled Alloy Group ⁇ - ⁇ , Alloy Group IIl-B, Alloy Group IH-C, Alloy Group IV-A, Alloy Group IV-B, and Alloy Group IV-C are provided.
• the Alloy Group 111 alloys are suitable for permanent mold casting.
• the Alloy Group IV alloys are suitable for wrought applications.
• the alloys of the present invention comprise copper, zinc, tin, sulfur, nickel, and phosphorus.
• one or more of manganese, zirconium, boron, titanium and/or carbon are included.
• Embodiments, other than Group IV wrought yellow brass, also include one or more of antimony, tin, nickel, phosphorus, aluminum, and silicon.
• the alloys comprise as a principal component, copper.
• Copper provides basic properties to the alloy, including antimicrobial properties and corrosion resistance. Pure copper has a relatively low yield strength, and tensile strength, and is not very hard relative to its common alloy classes of bronze and brass. Therefore, it is desirable to improve the properties of copper for use in many applications through alloying.
• the copper will typically be added as a base ingot.
• the base ingot's composition purity will vary depending on the source mine and post- mining processing. Therefore, it should be appreciated that ingot chemistry can vary, so, in one embodiment, the chemistry of the base ingot is taken into account. For example, the amount of zinc in the base ingot is taken into account when determining how much additional zinc to add to arrive at the desired final composition for the alloy.
• the base ingot should be selected to provide the required copper for the alloy while considering the secondary elements in the base ingot and their intended presence in the final alloy since small amounts of various impurities, such as iron, are common and have no material effect on the desired properties.
• Lead has typically been included as a component in copper alloys, particularly for applications such as plumbing where machinability is an important factor.
• Lead has a low melting point relative to many other elements common to copper alloys.
• lead in a copper alloy, tends to migrate to the interdendritic or grain boundary areas as the melt cools.
• the presence of lead at interdendritic or grain boundary areas can greatly improve machinability and pressure tightness.
• the serious detrimental impacts of lead have made use of lead in many applications of copper alloys undesirable.
• the presence of the lead at the interdendritic or grain boundary areas the feature that is generally accepted to improve machinability, is, in part, responsible for the unwanted ease with which lead can leach from a copper alloy.
• Sulfur is added to the alloys of the present invention to overcome certain disadvantages of using leaded copper alloys.
• Sulfur present in the melt will typically react with transition metals also present in the melt to form transition metal sulfides.
• transition metal sulfides For example, copper sulfide and zinc sulfide may be formed, or, for embodiments where manganese is present, it can form manganese sulfide.
• Figure 23 illustrates a free-energy diagram for several transition metal sulfides that may form in embodiments of the present invention.
• the melting point for copper sulfide is 1 130 Celsius, 1 185 Celsius for zinc sulfide, 1610 Celsius for manganese sulfide, and 832 Celsius for tin sulfide.
• sulfide formation will be zinc sulfide for those embodiments having no manganese. It is believed that sulfides that solidify after the copper has become to solidify, thus forming dendrites in the melt, aggregate at the interdentric areas or grain boundaries.
• Sulfur provides similar properties as lead would impart to a copper alloy, without the health concerns associated with lead. Sulfur forms sulfides which it is believed tend to aggregate at the interdendritic or grain boundary areas. The presence of the sulfides provides a break in the metallic structure and a point for the formation of a chip in the grain boundary' region and improve machining lubricity, allowing for improved overall machinability. The sulfides predominate in the alloys of the present invention provide lubricity. Good distribution of sulphides improves pressure tightness, as well as, machinability.
• Zn is similar to that of Sn, but to a lesser degree, in certain embodiments approximately 2% Zn is roughly equivalent to 1 % Sn with respect to the above mentioned improvements to characteristics noted above.
• Zn increases strength and hardness by solid solution hardening.
• Cu-Zn alloys have a short freezing range.
• Zn is much less expensive than Sn.
• iron can be considered an impurity picked up from stirring rods, skimmers, etc during melting and pouring operations, or as an impurity in the base ingot. Such categories of impurity have no material effect on alloy properties.
• antimony may be considered an impurity in the described alloys. Typically, antimony is picked up from inferior brands of tin, scrap and poor quality of ingots and scrap. However, antimony is deliberately added to yellow brasses in a permanent mold to increase the dezincification resistance.
• nickel is included to increase strength and hardness. Further, nickel aids in distribution of the sulphide particles in the alloy. In one embodiment, adding nickel helps the sulfide precipitate during the cooling process of the casting. The precipitation of the sulfide is desirable as the suspended sulfides act as a substitute to the lead for chip breaking and machining lubricity during the post casting machining operations. With the lower lead content, it is believed that the sulfide precipitate will minimize the effects of lowered machinability.
• Phosphorus may be added to provide deoxidation. T e addition of phosphorus reduces the gas content in the liquid alloy. Removal of gas provides generally provides higher quality castings by reducing gas content in the melt and reducing porosity in the finished alloy. However, excess phosphorus can contribute to metal-mold reaction giving rise to low mechanical properties and porous castings.
• Aluminum is, in some embodiments, such as semi-red brasses and tin bronzes, treated as an impurity. In such embodiments, aluminum has harmful effects on pressure tightness and mechanical properties. However, aluminum in yellow brass castings can selectively improve casting fluidity. It is believed that aluminum encourages a fine feathery dendritic structure in such embodiments.
• Silicon is also considered an impurity. In foundries with multiple alloys, silicon based materials can lead to silicon contamination in non silicon containing alloys. A small amount of residual silicon can contaminate semi red brass alloys, making production of multiple alloys near impossible. In addition, the presence of silicon can reduce the mechanical properties of semi-red brass alloys.
• Manganese may be added in certain embodiments.
• the manganese is believed to aid in the distribution of sulfides.
• the presence of manganese is believed to aid in the formation of and retention of zinc sulfide in the melt.
• a small amount of manganese is added to improve pressure tightness.
• manganese is added as MnS. J0075J Either zirconium or boron may be added individually (not in combination) to produce a fine grained structure which improves surface finish of castings during polishing.
• Carbon may be added in certain embodiments to improve pressure tightness, reduce porosity, and improve machinability.
• Titanium may be added in combination with carbon, such as in graphite form. Without limiting the scope of the invention, it is believed that the titanium aides in bonding the carbon particles with the copper matrix, particularly for raw graphite. For embodiments utilizing copper coated with carbon, titanium may not be useful to distribute the carbon.
• an alloy of the present invention solidifies in a manner such that a multitude of discrete particles of sulfur/sulfide are distributed throughout in a generally uniform manner throughout the casting. These nonmetallic sulfur particles serve to improve lubricity and break chips developed during the machining of parts cast in this new alloy, thereby improving machinability with a significant or complete reduction in the amount of lead. Without limiting the scope of the invention, the sulfides are believed to improved lubricity.
• the preferred embodiments of the described alloy retain machinability advantages of the current alloys such as the "81 " alloy or a similar leaded alloy. Further, it is believe that due to the relative scarcity of certain materials involved, the preferred embodiments of the ingot alloy will cost considerately less than that of the bismuth and/or selenium alloyed brasses that are currently advocated for replacement of leaded brass alloys such as "81 ".
• the sulfur is present in certain embodiments described herein as a sulfide which is soluble in the melt, but is precipitated as a sulfide during solidification and subsequent cooling of the alloy in a piece part.
• This precipitated sulfur enables improved machinability by serving as a chip breaker similar to the function of lead in alloys such as the "81 " and in bismuth and selenium alloys.
• the formation of sulfides or selenides, along with some metallic bismuth accomplishes a similar objective as this new sulfur containing alloy.
• the improvement in machinability may show up as increased tool life, improved machining surfaces, reduced tool forces, etc.
• This new idea also supplies the industry with a low lead brass/bronze which in today's environment is seeing any number of regulatory authorities limit by law the amount of lead that can be contained in plumbing fittings.
• alloys to which lead has been added result in an increase in the temperature range over which solidification occurs, normally making it more difficult to produce a leak tight casting, critical in plumbing fittings.
• lead segregates to the last regions to solidify and thereby seals the interdendritic and grain boundary shrinkage which occurs. This sealing of interdendritic or grain boundary porosity is not accomplished in the sulfur/sulfide containing alloys. Neither is it accomplished in the bismuth and/or selenium alloys. While bismuth is similar to lead in the periodic table of the elements, and expands during solidification, the amount of bismuth used is small compared to the amount of lead in conventional alloys such as the "81 ". Bi is typically present in commercial alloys in the elemental form.
• the alloys of the present invention utilize abundantly found elements, whereas both bismuth and selenium are in relatively limited supply; and the conversion of brass castings to these materials will significantly increase the demand for these limited supply materials.
• bismuth has some health concerns associated with its use in plumbing fixtures, in part due to its proximity to lead as a heavy metal on the periodic table.
• the alloys of the present invention utilizes a lower percent of copper than prior art bismuth and selenium compositions.
• zinc of the present invention reduces the tendency for de-zincification. Further, if typically the product is to be finished with a chrome plated surface, the silicon based materials require a copper or tin strike prior to plating which increases the cost of the plating. The alloys of the present invention do not require the additional step (and its associated costs) to allow for chrome plating.
• graphite is placed on the bottom of the crucible prior to heating.
• silicon carbide or clay graphite crucibles may be used in the melts. It is believed that the use of graphite reduces the loss of zinc during the heat without substantially becoming incorporated into the final alloy.
• approximately two cups of graphite are used for a 90 to 95 lbs capacity crucible.
• a B-30 crucible was used for the melts, which has a capacity of 90 to 95 lbs of alloy.
• the required base ingot is placed in the crucible and the furnace started.
• the base ingot is brought to a temperature of about 2, 100 degrees Falirenheit to form a melt.
• a conventional gas-fired furnace is used, and in another an induction furnace is used.
• the fumace is then turned off, i.e. the melt is no longer heated.
• the additives except, in one embodiment, for sulfur and phosphorus, are then plunged into the melt between 15 to 20 seconds to achieve desired levels of Zn, Ni and Sn.
• the additives comprise the materials needed to achieve the final desired alloy composition for a given base ingot.
• the additives comprise elemental forms of the elements to be present in the final alloy. Then a partial amount of slag is skimmed from the top of the melt.
• the furnace is then brought to a temperature of about 2, 140 Fahrenheit.
• the fumace is then shut off and the sulfur additive is plunged in.
• the furnace is then reheated to a temperature of about 2, 150 degrees Fahrenheit and phosphorous is plunged into the melt as a Cu-P master alloy.
• phosphorous is plunged into the melt as a Cu-P master alloy.
• Tail castings for pressure testing and evaluation of machinability and plating, buttons, wedges and mini ingots for chemical analysis, and web bars for tensile testing are poured at about 2 100. about 2040, and about 2000 F respectively.
• the furnace is fired to about 2, 140 Fahrenheit for Alloy Groups 1-A and I-B.
• the furnace is fired to about 2,050 Fahrenheit for Alloy Group II-A.
• Machinability testing described in the present application was performed using the following method.
• the piece parts were machined by a coolant fed, 2 axis, CNC Turning Center.
• the cutting tool was a carbide insert.
• the machinability is based on a ratio of energy that was used during the turning on the above mentioned CNC Turning Center.
• the calculation formula can be written as follows:
• E2 Energy used during the turning of a "known" alloy C 36000 (CDA).
• Figures 3A-6 correspond to the specific tested formulations and the corresponding results for the Ally Group 1-A. Alloy Group I-B, and Alloy Group II-A.
• 10089 J Figures 3A and 3B correspond to the specific tested formulations and the corresponding results for the Ally Group I-A.
• the average for the eight Alloy Group I-A alloys was 40.25 ksi for ultimate tensile strength, 1 7.1 ksi for yield strength, 47 for percent elongation, 63 for Brinnell hardness, and 13.5 for Modulus of Elasticity.
• Figures 4A and 4B correspond to the specific tested formulations and the corresponding results for the Ally Group I-B.
• the average for the nine Alloy Group I-B alloys was 38. 1 ksi for ultimate tensile strength, 17.5 ksi for yield strength, 32 for percent elongation, 64 for Brinnell hardness, and 13.8 for Modulus of Elasticity.
• J Figures 5 A and 5B correspond to the specific tested formulations and the corresponding results for the Ally Group Il-A.
• the average for the eight Alloy Group Il-A alloys was 43.8 ksi for ultimate tensile strength, 23 ksi for yield strength, 27 for percent elongation, 80 for Brinnell hardness, and 15.0 for Modulus of Elasticity.
• Table 9 illustrates the range of mechanical properties determined experimentally for alloys of the present invention, as well as for several known commercial alloys.
• Figure 37 shows the observed UTS was consistently higher than the commercial alloys.
• Figure 38 shows the observed YS was consistently higher than all of the commercial alloys except C89520, an alloy containing the expensive rare element bismuth.
• Figure 39 shows the observed elongation was consistently much higher than all of the commercial alloys. Elongation did exhibit variability from heat to heal for Group 1-A.
• Figure 40 shows the observed UTS was consistently higher than the commercial alloys.
• Figure 41 shows the observed YS was consistently higher than all of the commercial alloys, again, except C89520, an alloy containing the expensive rare element bismuth.
• Figure 42 shows the observed elongation was consistently higher than all of the commercial alloys. Elongation did exhibit significant variability from heat to heat for Group I-B.
• Group II-A alloys were also compared with leaded alloy C90300 (depicted as— ), in addition to the commercial alloys used in as previously discussed.
• Figure 43 shows the observed UTS was consistently higher than the commercial alloys, including slightly higher than C90300.
• Figure 44 shows the observed YS was consistently higher than all of the commercial alloys including C89520.
• Figure 45 shows the observed elongation was consistently higher than all of the commercial alloys. Elongation did exhibit significant variability from heat to heat for Group II-A.
• Table 1 0 ( Figure 7) lists the compositions of five alloys of the present invention. Alloy I- A- 10, Alloy l-B-10, Alloy II-A- 10, Alloy II-B- 10, and Alloy III-A-10, that were analyzed using a scanning electron microscope equipped with energy dispersive spectroscopy (SEM/EDS). A sample of each alloy in Table 10 was mounted, metallographically prepared according to known methods and then examined both optically and using SEM EDS. For comparison, the BiwaliteTM(C83470) alloy was melted and cast under conditions similar to alloy I-A and used for evaluation and comparison of microstructure.
• SEM/EDS energy dispersive spectroscopy
• Figures 8A and 8B illustrate element mapping of sulfur in Alloy I-A- 10 (0.16% S).
• Figure 9A is an SEM of Alloy I-A- 10;
• Figures 9B-H illustrate element mapping;
• Figure 9B is an EDS for Sn;
• Figure 9C is an EDS for Zn;
• Figure 9D is an EDS for Cu;
• Figure 9E is an EDS for Fe;
• Figure 9F is an EDS for Ni;
• Figure 9G is an EDS for P;
• Figure 9H is an EDS for S.
• Figure 1 OA is a micrograph of Alloy I-A- 10a, with regions 1 , 2, and 3 marked; Figures 10B-D show the presence of Cu2S, ZnS and Cu-Zn intermetallic phases: Figure 10B is an EDS spectra from region 1 : Figure I OC is an EDS spectra from region 2; Figure 10D is an EDS spectra from region 3.
• Figures 1 1A-B are optical images of Alloy I-A-10 at low ( Figure 1 1 A) and high magnifications (Figure 1 I B). The elements are seen widely distributed except for sulfur, which appears collected at what is believe to be interdcntric areas or grain boundaries.
• Figures 12A and 12B illustrate element mapping of sulfur in Alloy I-B- 10 (0.31 % S).
• Figure 13A is an SEM of Alloy I-B- 10;
• Figures 1 3B-H illustrate element mapping;
• Figure 13B is an EDS for Sn;
• Figure 13C is an EDS for Zn:
• Figure 13D is an EDS for Cu;
• Figure 13E is an EDS for Fe;
• Figure 13F is an EDS for Ni;
• Figure 12G is an EDS for P;
• Figure 13H is an EDS for S.
• Figure 14A is an SEM of Alloy I-B- 10b; Figures 14B-H illustrate element mapping at 5000x magnification; Figure 14B is an EDS for Si; Figure 14C is an EDS for S; Figure 14D is an EDS for Fe; Figure 14E is an EDS for Cu; Figure 14F is an EDS for Zn; Figure 1 G is an EDS for Sn; Figure 14H is an EDS for Pb; Figure 14 I is an EDS for Ni.
• Figures 15A-B arc optical images of Alloy I-B-10 at low ( Figure 15 A) and high magnifications (Figure 15B). The elements are seen widely distributed except for sulfur, which appears collected at what is believe to be interdentric areas or grain boundaries.
• Figure 1 7A is an SEM of Alloy II-A; Figures 17B-H illustrate element mapping; Figure I 5B is an EDS for Sn; Figure 1 7C is an EDS for Zn; Figure 17D is an EDS for Cu; Figure 1 7E is an EDS for Fe; Figure 1 7F is an EDS for Ni; Figure 17G is an EDS for P; Figure 17H is an EDS for S.
• Figure 18A is an SEM of Alloy II-A-10b (0.19% S); Figures 18B-H illustrate element mapping at l OOOx magnification; Figure 18B is an EDS for Si; Figure 18C is an EDS for S; Figure 1 8D is an EDS for Fe; Figure 18E is an EDS for Cu; Figure 1 8F is an EDS for Zn; Figure 18G is an EDS for Sn: Figure 1 811 is an EDS for Pb; Figure 1 8 I is an EDS for Ni.
• Figures 19A- B arc optical images of Alloy II-A at low (Figure 19A) and high magnifications (Figure 19B). The elements are seen widely distributed except for sulfur, which appears collected at what is believe to be interdentric areas or grain boundaries. These figures show the presence of Cu2S. ZnS, and intermetallic phases of Cu-Sn and Cu-Zn.
• Figures 20A and 20B illustrate element mapping of sulfur in Alloy ⁇ - ⁇ (0.01 1% S).
• Figure 21 A is an SEM of Alloy III-A;
• Figures 121 B-H illustrate element mapping;
• Figure 21B is an EDS fur Sn;
• Figure 21 C is an EDS for Zn;
• Figure 21 D is an EDS for Cu;
• Figure 2 IE is an EDS for Fe;
• Figure 21 F is an EDS for Ni;
• Figure 21 G is an EDS for P;
• Figure 21 H is an EDS for S.
• Figures 22A-B arc optical images of Alloy 111-A at low ( Figure 22A) and high magnifications (Figure 22B). The elements are seen widely distributed except for sulfur, which appears collected at what is believe to be interdentric areas or grain boundaries.
• Alloys 1-A-l through l -A-5 and Alloys 1-15- 1 and II-A- 1 were formulated and made in accordance with the present invention.
• Alloy C83470 is a known alloy whose full composition is listed in Table 1 ( Figure 1 ).
• Alloys 1 - B- l l a and II-A-1 l a are nominal compositions for Alloy Groups I-B and II-A respectively.
• nominal composition of commercially available alloys C84000 and C83470 (BiwaliteTM) is also included in Table 1 1.
• Table 1 1 Alloy Compositions for Phase Analysis
• Figure 24 plots the position of the alloys in table 12 on a copper/zinc/tin phase diagram. The alloys proceed from the highest percentage of copper and zinc on the left to the lowest copper and zinc on the right.
• a phase distribution diagram of I-A-l l a ( Figures 25 A and 25B), I- ⁇ - 1 l b ( Figures 26 ⁇ and 26B), 1-A- l l c ( Figures 27A and 27B), I-A-l I d ( Figures 28 A and 28B), I-A- l l e ( Figures 29A and 29B), using Scheil cooling is shown in Figure 25 A and 25B.
• Figures 31. 32A. and 32B correspond to Alloy I-A- 12f.
• Figures 33, 34A, and 34B correspond to Alloy I- B-12a.
• Figures 35, 36A, and 36B correspond to Alloy II-A- 12a.
• the relative amounts of the melt having FCC, Liquid, BCCi, BCC?, Cu 2 S, and Cu 3 Sn in relation to temperature is shown in Figures 22A and 22B (magnified to show the distribution of the secondary phases).
• Figures 30A-30B illustrates a similar series of phase distributions as Figures 25A-29, but for an existing commercial alloy, C83470.
• Figure 30A is a phase distribution diagram of C83470 alloy using Scheil cooling.
• Figure 30B is a magnified part of the phase distribution diagram showing the relative amounts of secondary phases.
• phase distribution diagrams show the phase that can be expected and the temperature at which they start appearing. The relative amount of each phase can also be estimated from these diagrams. Table 12 is based on these diagrams which shows that for non-equilibrium cooling, it is the ⁇ (BCC l ) phase (which is an intermetallic compound of Cu and Zn) that contributes to the strength of the alloys. However, strength increases at the expense of ductility. Sloan Green alloys show high strength and ductility. Their high ductility may be due to the good melt quality, low gas content and good homogeneity. The finer distribution of sulfides also contribute to high strength and high ductility in addition to contributing to pressure tightness and machinability.
• the sample was heated from room temperature to 1080 °C. Then it was cooled to 800 °C and kept at that temperature for 10 minutes, 600 s. This is termed "first heating and cooling cycle.' * In the second and third cycles the sample was heated to 1080 °C and then cooled to 800 °C twice. Finally the sample was cooled down to room temperature. A constant rate of 5 °C /min was used for all heating and cooling.
• a baseline experiment, with two empty graphite crucibles was run using the same experimental program. The baseline was subtracted for all runs. The analysis for temperatures and enthalpies was carried on these baseline adjusted thermograms.
• BiwaliteTM(C83470) has a medium freezing range.
• the alloys of Table 13 have a broad freezing range.
• BiwaliteTM(C83470) one can expect a deep pipe in the riser which can extend to the casting to produce shrinkage porosity.
• broad freezing range alloys porosity can be distributed well in the casting.
• it can be minimized / eliminated by using proper risering design and/or by using metal chills.
• the alloys 1-A, I-B, and II-A of Table 13 can be less susceptible to shrinkage porosity. This would lead to better strength and elongation values which we have observed.

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