CN112567057A

CN112567057A - Lead-free superhard self-lubricating copper alloy and manufacturing method thereof

Info

Publication number: CN112567057A
Application number: CN201880096907.9A
Authority: CN
Inventors: 黄劲松; 金鑫; 封治国
Original assignee: Hunan Terry New Materials Co ltd
Current assignee: Hunan Terry New Materials Co ltd
Priority date: 2018-08-27
Filing date: 2018-08-27
Publication date: 2021-03-26
Also published as: WO2020041925A1

Abstract

The invention discloses a lead-free superhard self-lubricating copper alloy and a manufacturing method thereof, wherein the copper alloy comprises the following elements in percentage by mass: 52.0% -85.0% of copper; 4.0 to 9.0 percent of manganese; 1% -3% of aluminum; 1% -3% of iron; 0.2% -0.8% of silicon; 0.2 to 0.6 percent of nickel; 1.36 to 4.07 percent of sulfur; except copper, iron, nickel and zinc, the affinity with sulfur is less than that of manganese and sulfur, and the sum of the contents is less than or equal to 15.0 percent; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent. The lead-free superhard self-lubricating copper alloy has excellent wear resistance, antifriction and anti-lock capacity, excellent technological performance such as cutting, cold and hot deformation and other performances, and excellent use performance such as high hardness.

Description

Lead-free superhard self-lubricating copper alloy and manufacturing method thereof

Technical Field

The invention relates to a lead-free superhard self-lubricating copper alloy and a manufacturing method thereof.

Background

When one object moves or tends to move relative to the other object along the tangent line of the contact surfaces, there is a force between the contact surfaces of the two objects that resists their relative movement, which is called friction. This phenomenon or characteristic between the contacting surfaces is called "rubbing". It is estimated that approximately 1/2-1/3 of energy worldwide is consumed in friction in various forms. While friction-induced wear is a major cause of mechanical equipment failure, approximately 80% of part damage is due to various forms of wear. Rubbing is an irreversible process with consequent energy losses and loss or migration of the rubbing surface material, i.e. wear, which can lead to surface damage and material loss. Since friction is inevitable and wear is inevitable, it cannot be eliminated and one can only reduce friction and thus wear in thousands of ways. Although there are many factors that affect wear, experience has shown that the higher the hardness of a metallic material, the more wear resistant. Therefore, most of the wear-resistant metal materials are high-hardness materials such as high-chromium cast iron and even hard alloy. In order to improve the wear resistance of the workpiece, i.e., to improve the service life of the workpiece during friction operation, a metal material with higher hardness is generally considered. The friction couple generally works together with two mating parts. If hard or soft materials are used for both partners, both partners are prone to fail and the friction pair fails. A pair of excellent friction pairs is formed by matching a hard coupling part with a soft coupling part and optimizing the hardness of the hard coupling part and the soft coupling part to realize the best matching. Moreover, the soft counterpart should be relatively easy to replace, so that the lowest cost and the best technical and economic value of the friction couple can be achieved. Because the friction pair can generate relative motion when in work, the friction pair does work under the action of force and is converted into heat so as to heat the friction pair. To optimize the service life of the friction pair, the following factors are of importance: the hardness of the two mating parts is matched, the moving contact surface is lubricated, and the friction heat is timely dissipated. The sliding bearing, especially to action precision relatively high, the copper base bearing of selecting more uses, this is because the copper alloy has excellent heat conduction heat-sinking capability, does not lead to because of the heat can not in time lead away and make the vice temperature of friction too high, and then reduce vice intensity aggravation wearing and tearing of friction and make the mechanism lose efficacy prematurely. In the machine tool manufacturing industry, because the shaft is made of heat-treated steel widely, the high hardness and the high wear resistance of the shaft are very strong. The hardness of the copper-based bearing of the mating part of the heat treatment steel is generally much lower than that of the heat treatment steel shaft, and in order to improve the service life, the hardness of the copper-based bearing is improved as much as possible, namely, the superhard copper-based bearing is matched with the heat treatment steel shaft. In particular, in the mold industry, the requirement on the motion precision is high, and the design key point of the dual copper sleeve is to select a copper alloy with higher hardness so as to improve the wear resistance and further prolong the service life. Copper and copper alloy are softer non-ferrous metal materials, the hardness of the copper and copper alloy is difficult to improve, and the copper alloy with higher hardness is the target of cumin materials research workers. The coefficient of thermal expansion of copper is obviously higher than that of steel, if the copper-based bearing and a shaft which moves in a matched mode generate friction heat so that the size of the inner diameter of the bearing is reduced, the steel shaft can be occluded and locked by the copper-based bearing, and therefore in order to prevent the situation, the higher the self-lubricating and wear-reducing capacity of the copper-based bearing is, the better the self-lubricating and wear-reducing capacity is.

Good lubrication is important to improve the service life of the friction pair, as it is an important means of reducing friction. The liquid film lubrication effect is very good, and is the first means for reducing friction, such as adding lubricating oil in a motion mechanism. The oil-containing self-lubricating bearing has a large number of pores, is filled with a large number of lubricating oil, has a very good lubricating effect and is widely used. Due to the oil-containing characteristic, the self-lubricating bearing is bound to have a large number of pores for storing oil, so that the strength, hardness and toughness of the self-lubricating bearing are very low, and the self-lubricating bearing can only be used in a light-load low-speed scene. The oil-retaining bearing can not meet the use requirement under the conditions of medium-high speed and medium-heavy load, particularly under the scene with high requirement on motion precision. Because the liquid has fluidity, the liquid is easy to overflow out of friction pairs to pollute a system, and the liquid is limited to be used in environments such as food machinery, medical machinery, electronic machinery, vacuum dust-free environment and the like in many cases. On the other hand, when the addition of the lubricating fluid is inconvenient or lubrication failure occasionally occurs even if the lubricating fluid is present, the life of the friction pair is strongly reduced. These cases require the use of solid phase friction reducers to effectively increase the friction reducing ability of the friction pair. When no liquid film is used for lubrication, solid-phase antifriction, namely self-lubrication, is the only means for reducing abrasion, prolonging the service life of the mechanism and improving the efficiency.

The lead brass has the characteristics of good self-lubricating property, cold and hot processing property, excellent cutting property and the like, is considered as an important basic metal material by the world at one time and is widely applied to the fields of mechanical manufacturing and the like. Because lead brass is widely used, the number of waste lead brass spare and accessory parts is large, only a small amount of the waste lead brass spare and accessory parts is recycled, and a large amount of small parts are abandoned as garbage. The waste lead brass is in contact with soil, and lead contained in the waste lead brass enters the soil under the long-term action of rainwater and atmosphere, so that the soil and a water source are polluted. When the waste lead brass is used as garbage for incineration, lead vapor is emitted into the atmosphere, which causes great harm to human bodies, so that the application of the waste lead brass is increasingly limited by laws and regulations. And the lead brass has low hardness and low self-lubricating capability, which is not ideal no matter the wear resistance or self-lubricating antifriction capability, and can not meet the requirement of a friction pair.

Tin bronze is used as a traditional bearing material, has moderate strength and hardness, certain self-lubricating capacity and strong machining capacity, and is widely used in the mechanical industry for a long time. However, it must be noted that the self-lubricating ability is low, and the scenario with high self-lubricating ability cannot be satisfied. The hardness of tin bronze is not high, the wear resistance is general, and the application scene of heavy load in medium and high speed can not be met. After the self-lubricating high-force brass is drilled in the bearing and solid-phase lubricating particles such as graphite or molybdenum disulfide and the like are embedded in the holes, the self-lubricating high-force brass has good self-lubricating capability, the hardness of the self-lubricating high-force brass can reach HB220 at most, the toughness is good, the wear resistance is strong, and the application scene of medium-high speed medium-heavy load can be basically met. However, the self-lubricating high-force brass has to be drilled when the solid-phase lubricating phase is embedded, and the distribution of the holes is non-uniform, so that the non-uniform damage of the high-force brass bearing is caused, the strength and hardness consistency of the high-force brass bearing is seriously reduced, and the non-uniform abrasion of the high-force brass bearing is caused. Especially under the use condition of medium-high speed and heavy load, abnormal abrasion failure is easy to occur. On the other hand, the uneven distribution of pores also causes uneven distribution of solid phase particles, which in turn causes uneven friction reduction capability. The self-lubricating high-force brass is an excellent antifriction and wear-resistant copper alloy, but is not an ideal antifriction and wear-resistant copper alloy.

Disclosure of Invention

The invention solves the technical problem that the market strongly needs a novel copper alloy to overcome the defects of the antifriction and wear-resistant copper alloy. The demand is to develop a compact oil-free lead-free superhard self-lubricating anti-lock copper alloy with uniform solid-phase lubricating particles and uniform matrix performance so as to completely meet the application scene of high-precision medium-high speed medium-heavy load actions. The present invention has been developed in view of this need.

The technical scheme of the invention is to provide a lead-free superhard self-lubricating copper alloy, which comprises the following elements in percentage by mass:

52.0% -85.0% of copper; 4.0 to 9.0 percent of manganese; 1% -3% of aluminum; 1% -3% of iron; 0.2% -0.8% of silicon; 0.2 to 0.6 percent of nickel; 1.36 to 4.07 percent of sulfur;

except copper, iron, nickel and zinc, the affinity with sulfur is less than that of manganese and sulfur, and the sum of the contents is less than or equal to 15.0 percent;

the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.

Preferably, the metal having a lower affinity for sulfur than manganese is cobalt, tin, tungsten, molybdenum, niobium, antimony, and bismuth.

Preferably, the mass fractions of the elements in the copper alloy are as follows: 54.0% -72.0% of copper; 4.5 to 8.0 percent of manganese; 1.2 to 2.8 percent of aluminum; 1.2 to 2.8 percent of iron; 0.3% -0.8% of silicon; 0.2 to 0.5 percent of nickel; 1.50 to 3.50 percent of sulfur; except copper, iron, nickel and zinc, the affinity with sulfur is less than that of manganese and sulfur, and the sum of the contents is less than or equal to 15.0 percent; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.

Preferably, the mass fractions of the elements in the copper alloy are as follows: 56.0% -68.0% of copper; 5.0 to 7.0 percent of manganese; 1.4% -2.6% of aluminum; 1.4% -2.6% of iron; 0.3% -0.8% of silicon; 0.3 to 0.5 percent of nickel; 1.70% -3.00% of sulfur; except copper, iron, nickel and zinc, the affinity with sulfur is less than that of manganese and sulfur, and the sum of the contents is less than or equal to 15.0 percent; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.

Preferably, the mass fractions of the elements in the copper alloy are as follows: 58.0 to 65.0 percent of copper; 5.0 to 7.0 percent of manganese; 1.6 to 2.4 percent of aluminum; 1.6 to 2.4 percent of iron; 0.3% -0.7% of silicon; 0.3 to 0.5 percent of nickel; 1.90 to 2.80 percent of sulfur; except copper, iron, nickel and zinc, the affinity with sulfur is less than one or more of metals of manganese and sulfur, and the sum of the contents is 1.0-15.0%; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.

Preferably, the mass fractions of the elements in the copper alloy are as follows: 59.0 to 62.0 percent of copper; 5.0 to 7.0 percent of manganese; 1.7 to 2.3 percent of aluminum; 1.7 to 2.3 percent of iron; 0.3% -0.7% of silicon; 0.3 to 0.5 percent of nickel; 2.10 to 2.60 percent of sulfur; one or more of metals except copper, iron, nickel and zinc, the affinity of which with sulfur is less than that of manganese, and the sum of the contents is 1.0-15.0%; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.

The invention also provides a manufacturing method of the copper alloy, which comprises the following steps:

(1) sequentially melting copper, nickel, copper-iron intermediate alloy, manganese, silicon, zinc and aluminum, and preparing copper alloy raw material powder by an atomization method after alloy elements are homogenized;

(2) mixing copper alloy raw material powder with metal sulfide, adding 0.5-1.5% of forming agent, and mixing for 0.5-8h to uniformly mix various powders; the affinity of the metal in the metal sulfide to sulfur is less than that of manganese to sulfur;

(3) and (3) pressing and molding the uniformly mixed powder, and then sintering, wherein the sintering process comprises the following steps: heating from room temperature to a sintering temperature of 650-870 ℃, heating for 1-5h, and keeping the temperature for 30-300min, wherein the sintering atmosphere is a reducing atmosphere or an inert atmosphere;

(4) heating the sintered copper alloy to 800 ℃ at 300-; then re-sintering, wherein the re-sintering process comprises the following steps: heating from room temperature to 800-870 ℃ of sintering temperature, heating for 1-16h, and keeping the temperature for 30-300min, wherein the re-sintering atmosphere is a reducing atmosphere or an inert atmosphere;

(5) and thermally deforming the re-sintered copper alloy at the temperature of 650-870 ℃.

Preferably, the copper alloy raw material powder is prepared by a gas atomization method or a water atomization method.

Preferably, the metal sulfide is a solid metal sulfide.

Preferably, the solid metal sulfide is selected from sulfides of eleven metals, iron, cobalt, nickel, tin, tungsten, molybdenum, niobium, copper, zinc, antimony, and bismuth.

Preferably, the sulfide of the eleven metals is copper sulfide, cuprous sulfide, zinc sulfide, tin sulfide, nickel sulfide, iron sulfide, ferrous disulfide, ferrous sulfide, tungsten sulfide, cobalt sulfide, molybdenum disulfide, molybdenum trisulfide, antimony tetrasulfide, antimony pentasulfide, antimony trisulfide, bismuth trisulfide, niobium disulfide and niobium trisulfide.

Preferably, the solid metal sulfide is copper sulfide, zinc sulfide or iron sulfide.

Preferably, the thermal deformation is hot forging or hot extrusion.

Manganese has obvious solid solution strengthening effect on brass, and the strengthening attenuation effect generated by the increase of the manganese is not obvious. The manganese content of the brass is controlled to be 4.0-9.0%, and the brass has a good effect of improving the hardness of the brass. The aluminum is a strong strengthening element of the brass, the hardness of the brass can be obviously improved, and the aluminum is controlled to be 1-3 percent in the invention; the iron plays a role in refining grains in the brass and can also inhibit the growth of grains during recrystallization, the iron content is controlled to be 1-3%, and the brass has a good effect of improving the hardness of the brass. The silicon and the nickel have solid solution strengthening effect on the brass, the content of the silicon is controlled to be 0.2-0.8 percent, the content of the nickel is controlled to be 0.2-0.6 percent, the small-amount multi-element strengthening effect is very obvious, and the hardness of the alloy is obviously improved. Other elements such as cobalt, tin, tungsten, molybdenum, niobium, antimony, bismuth, etc., also have strengthening effects on brass. The brass has very high hardness, and is a result of the combined action of manganese, aluminum, iron, silicon, and other strengthening elements.

The invention adopts a method of adding manganese and metal sulfide into copper alloy at the same time, and because the activity of manganese is higher than that of the metal in the added metal sulfide in the sintering process, the sulfide reacts with manganese to generate manganese sulfide in situ or a mixture which takes manganese sulfide as the main component and is mixed with other sulfides. The in-situ reaction product manganese sulfide has a layered structure, has the structural characteristics similar to those of graphite, and also has the characteristics of softness and smoothness. The presence of manganese sulphide in the copper alloy corresponds to the presence of soft particles having a lubricating effect in the copper alloy, producing a self-lubricating effect similar to that of graphite. The manganese sulfide generated in situ is well combined with the copper alloy crystal grains, the interface is coherent or semi-coherent, and the bonding strength is high. The combination of graphite particles and copper alloy grains in the graphite self-lubricating copper alloy does not have the effect of manganese sulfide particles, impurities often exist in the interface, the combination strength is low, and the hardness is low and the deformation capability is poor due to the factors. The superhard self-lubricating copper alloy has good lubricating effect, and has higher hardness and better cold and hot deformation capability than graphite self-lubricating copper alloy. On the other hand, because the interface strength of the manganese sulfide generated in situ is high, the addition amount can be increased greatly without reducing the cold-heat deformability of the superhard self-lubricating copper. The graphite particles and the copper alloy crystal grains are in simple mechanical engagement, so that the cold and hot deformability of the copper alloy is obviously reduced, and the self-lubricating capability of the copper alloy is limited due to the limited addition amount of the graphite particles.

The invention has the advantages that: the lead-free superhard self-lubricating copper alloy has excellent wear resistance, antifriction and anti-lock capacity, excellent technological performance such as cutting, cold and hot deformation and other performances, and excellent use performance such as high hardness. The friction coefficient of the alloy is small and the abrasion loss is extremely small under the dry friction condition of 180r/min, -50N and 30min by an American UMT-3 friction tester. The anti-seizing capability is strong, and the wear-resisting and anti-wear device is suitable for wear-resisting and anti-wear purposes such as copper sleeves, guide sleeves matched with dies, wear-resisting plates and the like in the machine tool machinery manufacturing industry. The porosity is low, the relative density is higher than 99.7%, the oil is dense and free (oil immersion is not needed when the bearing is manufactured), and the method is particularly suitable for scenes without oil film lubrication. The components do not contain harmful elements such as lead, cadmium, mercury, arsenic and the like, and the production process is pollution-free and environment-friendly.

Detailed Description

Example 1:

the mass fractions of the elements in the copper alloy raw material powder are respectively as follows: 58.0% of copper, 5.0% of manganese, 2.6% of aluminum, 2.2% of iron, 0.8% of silicon, 0.5% of nickel, and the balance of zinc and inevitable impurities. The mass fractions of the various powders are respectively as follows: the sulfide powder is a mixture of copper sulfide powder and zinc sulfide powder, and the content of the sulfide powder is 1.0 percent and 5.0 percent respectively; the content of the added forming agent paraffin powder is 0.5 percent; the balance being the above copper alloy raw material powder. The powder mixing time is 4.0h, the powder is pressed after the mixing is finished, the powder is placed into a sintering furnace for sintering after the pressing is finished, and the sintering process comprises the following steps: heating from room temperature to sintering temperature for 5.0h, fully removing the forming agent, wherein the sintering temperature is 680 ℃, the heat preservation time is 100min, and the sintering atmosphere is inert atmosphere. Re-pressing the sintered brass bar at 300 ℃ and 600MPa, and then re-sintering, wherein the re-sintering process comprises the following steps: heating from room temperature to a sintering temperature of 820 ℃, heating time of 3.0h, heat preservation time of 120min, and sintering atmosphere being inert atmosphere. The re-fired brass was hot extruded at 800 ℃. Sampling from the extrusion rod to prepare a tensile strength sample, a hardness, density and friction experiment sample and a shaft assembly simulation working sample. The experimental result shows that compared with the theoretical density of 100 percent (the powder metallurgy product generally has holes and can not be completely compacted), the relative density is 99.7 percent, the tensile strength of the alloy is 428.0MPa, the yield strength is 276.5MPa, the Brinell hardness is HB216.7, the friction coefficient is 0.151, the abrasion loss is 329.9 mu g, the simulation work of the assembled shaft and bearing is completely normal, and the locking phenomenon does not occur.

Examples 2-33 the mass fractions of the constituent elements of the raw material powders of the copper alloys in all of examples 2-33 are shown in table 1, the mass fractions of the respective powders when mixed are shown in table 2, the process parameters in the production of the copper alloys in the corresponding examples are shown in table 3, and the properties of the copper alloys in the corresponding examples are shown in table 4.

TABLE 1 mass fractions of respective elements in copper alloy raw material powders in all examples

TABLE 2 mass fractions for the various powders in all examples when mixed

TABLE 3 copper alloy manufacturing Process parameters in all examples

TABLE 4 Properties of the copper alloys in all examples

Claims

The lead-free superhard self-lubricating copper alloy is characterized in that the mass fractions of elements in the copper alloy are as follows:

52.0% -85.0% of copper;

4.0 to 9.0 percent of manganese;

1% -3% of aluminum;

1% -3% of iron;

0.2% -0.8% of silicon;

0.2 to 0.6 percent of nickel;

1.36 to 4.07 percent of sulfur;

except copper, iron, nickel and zinc, the affinity with sulfur is less than that of manganese and sulfur, and the sum of the contents is less than or equal to 15.0 percent;

the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.
The copper alloy of claim 1, wherein the metal having a lower affinity for sulfur than manganese is cobalt, tin, tungsten, molybdenum, niobium, antimony, and bismuth.
The copper alloy according to claim 1 or 2, wherein the mass fraction of each element in the copper alloy is: 54.0% -72.0% of copper; 4.5 to 8.0 percent of manganese; 1.2 to 2.8 percent of aluminum; 1.2 to 2.8 percent of iron; 0.3% -0.8% of silicon; 0.2 to 0.5 percent of nickel; 1.50 to 3.50 percent of sulfur; except copper, iron, nickel and zinc, the affinity with sulfur is less than that of manganese and sulfur, and the sum of the contents is less than or equal to 15.0 percent; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.
The copper alloy according to claim 1 or 2, wherein the mass fraction of each element in the copper alloy is: 56.0% -68.0% of copper; 5.0 to 7.0 percent of manganese; 1.4% -2.6% of aluminum; 1.4% -2.6% of iron; 0.3% -0.8% of silicon; 0.3 to 0.5 percent of nickel; 1.70% -3.00% of sulfur; except copper, iron, nickel and zinc, the affinity with sulfur is less than that of manganese and sulfur, and the sum of the contents is less than or equal to 15.0 percent; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.
The copper alloy according to claim 1 or 2, wherein the mass fraction of each element in the copper alloy is: 58.0 to 65.0 percent of copper; 5.0 to 7.0 percent of manganese; 1.6 to 2.4 percent of aluminum; 1.6 to 2.4 percent of iron; 0.3% -0.7% of silicon; 0.3 to 0.5 percent of nickel; 1.90 to 2.80 percent of sulfur; except copper, iron, nickel and zinc, the affinity with sulfur is less than one or more of metals of manganese and sulfur, and the sum of the contents is 1.0-15.0%; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.
The copper alloy according to claim 1 or 2, wherein the mass fraction of each element in the copper alloy is: 59.0 to 62.0 percent of copper; 5.0 to 7.0 percent of manganese; 1.7 to 2.3 percent of aluminum; 1.7 to 2.3 percent of iron; 0.3% -0.7% of silicon; 0.3 to 0.5 percent of nickel; 2.10 to 2.60 percent of sulfur; one or more of metals except copper, iron, nickel and zinc, the affinity of which with sulfur is less than that of manganese, and the sum of the contents is 1.0-15.0%; the balance of zinc and inevitable impurities, wherein lead in the impurities is less than or equal to 0.05 percent.
A method for producing the copper alloy according to any one of claims 1 to 6, comprising the steps of:

(1) sequentially melting copper, nickel, copper-iron intermediate alloy, manganese, silicon, zinc and aluminum, and preparing copper alloy raw material powder by an atomization method after alloy elements are homogenized;

(2) mixing copper alloy raw material powder with metal sulfide, adding 0.5-1.5% of forming agent, and mixing for 0.5-8h to uniformly mix various powders; the affinity of the metal in the metal sulfide to sulfur is less than that of manganese to sulfur;

(3) and (3) pressing and molding the uniformly mixed powder, and then sintering, wherein the sintering process comprises the following steps: heating from room temperature to a sintering temperature of 650-870 ℃, heating for 1-5h, and keeping the temperature for 30-300min, wherein the sintering atmosphere is a reducing atmosphere or an inert atmosphere;

(4) heating the sintered copper alloy to 800 ℃ at 300-; then re-sintering, wherein the re-sintering process comprises the following steps: heating from room temperature to 800-870 ℃ of sintering temperature, heating for 1-16h, and keeping the temperature for 30-300min, wherein the re-sintering atmosphere is a reducing atmosphere or an inert atmosphere;

(5) and thermally deforming the re-sintered copper alloy at the temperature of 650-870 ℃.
The production method according to claim 7, wherein the copper alloy raw material powder is produced by a gas atomization method or a water atomization method.
The method of manufacturing according to claim 7, wherein the metal sulfide is a solid metal sulfide.
The method of claim 9, wherein the solid metal sulfide is selected from the group consisting of iron, cobalt, nickel, tin, tungsten, molybdenum, niobium, copper, zinc, antimony, and bismuth eleven metal sulfides.
The method according to claim 10, wherein the sulfide of eleven metals is copper sulfide, cuprous sulfide, zinc sulfide, tin sulfide, nickel sulfide, iron sulfide, ferrous disulfide, ferrous sulfide, tungsten sulfide, cobalt sulfide, molybdenum disulfide, molybdenum trisulfide, antimony tetrasulfide, antimony pentasulfide, antimony trisulfide, bismuth trisulfide, niobium disulfide, or niobium trisulfide.
The method of claim 9, wherein the solid metal sulfide is selected from the group consisting of copper sulfide, zinc sulfide, and iron sulfide.
The manufacturing method according to claim 7, wherein the thermal deformation is hot forging or hot extrusion.