TW201627506A - Abrasion-resistant copper alloy - Google Patents

Abstract

The present invention provides a wear-resistant copper alloy that is strong, tough, and shock-resistant and that also has high-level wear resistance. This wear-resistant copper alloy contains, by mass, 10%-40% of Zn, 2%-9% of Al, 0.4%-3.5% of Fe, 0.5%-4.0% of Ni, 0.3%-2.0% of Co, 1.0%-5.0% of Mn, and 0.3%-3.5% of Si, the remainder comprising copper and unavoidable impurities, and is characterized by having a structure wherein an [alpha]+[beta] phase, an [alpha]+[beta]+[gamma] phase, and/or a [beta] phase has dispersed therein an Al-Fe-Mn-Si-Ni-Co-based intermetallic compound.

Description

Wear-resistant copper alloy

The present invention relates to a wear resistant copper alloy.

In the conventional brass alloys to be used for high-load-bearing applications, CAC301-CAC304 described in JIS H 5120 or high-strength brass materials (hereinafter referred to as Mn-Si series) of a manganese-based intermetallic compound crystal precipitation type are exemplified. . These materials are used for bushings or parts for construction machinery, and therefore require high strength, high hardness, and excellent wear resistance and resistance to fusion.

Incidentally, in the CAC301~CAC304 and Mn-Si systems (refer to, for example, Japanese Patent Literature 1, etc.), the ratios of the α phase, the β phase, and the γ phase are all due to the α phase + β phase, β phase structure, and the appearance of the added element. The zinc equivalent (hereinafter referred to as zinc equivalent) changes and decreases.

In the alloy composition, when the zinc equivalent is low, the mother phase structure is α single phase, and the toughness is high, but the strength, hardness, and wear resistance are low. When the load is high, the weight of the load may cause the material to be deformed or abraded. . In the case where the zinc equivalent is high, the γ phase is precipitated to become the β phase + γ phase, and the hardness and wear resistance are improved, but the strength, toughness, and punching value are remarkably lowered. Therefore, it is impossible to withstand the load-bearing load generated by the sliding portion.

Therefore, high-load-sliding applications must be such as α phase + β phase, α phase + β phase + γ phase, β phase, and exhibit a metal structure with balance of toughness, strength, hardness, wear resistance, and impact resistance. In the current situation, it is still impossible to satisfy the wear characteristics required for the weight reduction and long life of industrial machine parts in recent years.

It can also be inferred that the high-force brass system has a phase structure consistent with the Cu-Zn binary state diagram drawn by zinc equivalent, and the multi-system high-strength brass material is changed to the Cu-Zn binary state diagram. In the case where the zinc equivalent is about 50%, a γ phase is precipitated in the β phase. Since the γ phase is hard and not ductile, the β phase + γ phase structure has a significant adverse effect on strength, toughness, and impact resistance. Therefore, the addition of Si having a zinc equivalent coefficient of up to 10 in the range in which the β phase + γ phase is not generated is limited, and it is difficult to secure the abrasion resistance, strength, toughness, and impact resistance obtained by adding Si.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. Sho 51-41569

As a result of intensive studies by the present inventors, it has been found that all of the added Si and other elements added are used to form an intermetallic compound. The forming elements of the intermetallic compound do not form a solid solution in the parent phase, but have a slight effect on the mother phase structure. Then, as a result of further exploration, attention was paid to the elements Co, Fe, and Mn having a zinc equivalent coefficient lower than that of Zn. These elements form an intermetallic compound with Si at a certain ratio, and the solid solution of Si in the parent phase is remarkably suppressed. However, in a case of a certain ratio or more, Co, Fe, Mn, and Si elements are solid-solved, whereas Co, Fe, and Mn are solid-solved in the parent phase, and are lower than Si's zinc equivalent coefficient of 10, thus obtaining A slight conclusion on the impact of maternal organization. Thereby, a certain amount of Si added with a zinc equivalent coefficient of up to 10 is added between Fe, Mn, and Co to form an Al-Fe-Mn-Si-Co-based intermetallic compound, and crystals are precipitated, and a large amount of Si can be retained. The resulting high hardness and high wear resistance. Therefore, it is considered that by controlling and suppressing the solid solution element in the matrix phase, the maximum Si can be added, and although the zinc equivalent is high, the γ phase is not precipitated, and strength, toughness, and impact resistance can be maintained.

In other words, it is found that by controlling the solid solution of Si and other elements in the matrix phase, although the zinc equivalent is 50% or more, the strength, toughness, and impact resistance due to the precipitation of the γ phase do not occur, and Si can be added by adding Si. Seeking to improve wear resistance.

The present invention has been completed based on the above findings, and an object thereof is to provide an abrasion-resistant copper alloy which, by adding Si, does not generate a β phase + γ phase structure although the zinc equivalent is 50% or more, and has an α phase + β Phase structure of any of phase, α phase + β phase + γ phase, and β phase, and maintains strength, toughness, and impact resistance, and maintains high level of wear resistance.

The gist of the present invention is explained.

It is related to an abrasion-resistant copper alloy characterized by containing Zn: 10 to 40%, Al: 2 to 9%, Fe: 0.4 to 3.5%, and Ni: 0.5 to 4.0% by mass. : 0.3~2.0%, Mn: 1.0~5.0%, Si: 0.3~3.5%, the residual part is composed of Cu and unavoidable impurities, and has Al-Fe-Mn-Si-Ni-Co intermetallic compound dispersion A tissue of at least one of an α phase + a β phase, an α phase + a β phase + a γ phase, or a β phase.

Further, it is also related to the wear-resistant copper alloy according to claim 1, wherein the mass ratio of Fe, Mn, Co, and Si satisfies the following formula (1): [Number 1] 0.861 × Fe (% by mass) + 0.194 × Mn (% by mass) + 0.487 × Co (% by mass) ≧ Si (% by mass). . . (1)

Further, in addition to the wear-resistant copper alloy according to claim 1, the value obtained by the following formula (2) is substituted into the following formula (3), and the following formula (3) is satisfied. ):

Here, the left side A ^X is a value obtained by substituting the content of any one of Cu, Sn, Pb, Zn, Al, or Ni into the X on the right side, and the element of the X substituted on the right side is superscripted as A ^Cu. , A ^Sn , A ^Pb , A ^Zn , A ^Al or A ^Ni .

Further, in addition to the wear-resistant copper alloy according to the above-mentioned claim 2, the value obtained by the following formula (2) is substituted into the following formula (3), and the following formula (3) is satisfied. :

Here, the left side A ^X is a value obtained by substituting the content of any one of Cu, Sn, Pb, Zn, Al, or Ni into the X on the right side, and the element of the X substituted on the right side is superscripted as A ^Cu. , A ^Sn , A ^Pb , A ^Zn , A ^Al or A ^Ni .

The present invention is constructed as described above. Therefore, by adding Si, although the zinc equivalent is 50% or more, the β phase + γ phase structure is not generated, and the α phase + β phase, α phase + β phase + γ are obtained. The phase structure of either the phase or the β phase, and the wear-resistant copper alloy which maintains high strength, toughness, and impact resistance, and maintains high level of wear resistance.

Figure 1 is an electron micrograph of the metal structure of the sample.

Fig. 2 is a table showing the chemical composition of the sample (Example).

Fig. 3 is a table showing the chemical composition of a sample (Comparative Example).

Fig. 4 is a table showing the chemical composition of the sample (Example).

Fig. 5 is a table showing the chemical composition of a sample (Comparative Example).

Fig. 6 is a table showing various characteristic values of the sample (Example).

Fig. 7 is a table showing various characteristic values of the sample (comparative example).

Fig. 8 is an explanatory view of a Charpy test piece.

Figure 9 is a graph showing the relationship between the parent phase zinc equivalent and the tensile strength.

Figure 10 is a graph showing the relationship between the parent phase zinc equivalent and the ductility.

Figure 11 is a graph showing the relationship between the parent phase zinc equivalent and the summer ratio.

Fig. 12 is an explanatory view of a target material of the Daewoo wear test.

Fig. 13 is an explanatory view of a Fawei test piece.

Fig. 14 is an explanatory view of the object material of the Favi test.

Fig. 15 is a graph showing the comparison of the wear amounts of the examples and the comparative examples.

Fig. 16 is a graph showing the comparison of the wear amounts of the examples and the comparative examples.

Fig. 17 is a comparison diagram of the normal dimension values of the examples and the comparative examples.

The function of the present invention is disclosed below, and a description of what is considered to be a suitable embodiment of the present invention will be briefly described.

The invention relates to a wear-resistant high-force brass alloy. By adding Si, although the zinc equivalent is high, the γ phase is not precipitated, so the strength, the toughness and the impact resistance are obtained. The bismuth is not significantly deteriorated, and the Al-Fe-Mn-Si-Ni-Co intermetallic compound is crystallized and dispersed in the α phase + β phase, the α phase + the β phase + the γ phase, or the β phase structure. Seeking to improve wear resistance.

The reason why the component composition and the like are set as described above in the present invention will be described below.

Zn will solidify in the parent phase and determine strength, hardness, wear resistance, and parent phase structure. According to the amount of Zn, the amount of other added elements determines the mother phase structure as α phase, α phase + β phase + γ phase, α phase + β phase, β phase, β phase + γ phase, and if Zn does not reach 10% by mass, If the hardness is insufficient, abrasion is likely to occur, and the wear resistance is deteriorated. When Zn exceeds 40% by mass, Zn sufficiently strengthens the mother phase, but in the range where the γ phase does not precipitate, the strengthening by solid solution of Al is insufficient, and the zinc evaporation during casting is remarkable, so the amount of Zn added is increased. It is set to be 10% by mass to 40% by mass.

Al contributes to the formation of intermetallic compounds and improves wear resistance. In addition, it dissolves in the matrix phase and determines strength, hardness, wear resistance, and matrix structure. According to the amount of Al and the amount of other added elements, the mother phase structure is determined to be α phase, α phase + β phase + γ phase, α phase + β phase, β phase, β phase + γ phase, and if Al is less than 2% by mass, The hardness is insufficient, abrasion is likely to occur, and the abrasion resistance is likely to be deteriorated. When Al is more than 9% by mass, the β phase tends to exhibit an eutectoid transformation, and the γ ratio in the α phase + β phase + γ phase is increased, and the toughness is deteriorated. Therefore, the addition amount of Al is set to 2% by mass to 9 quality%.

Fe contributes to the formation of intermetallic compounds and improves wear resistance. If Fe is less than 0.4% by mass, the formation of a compound with Si is insufficient, if Fe is super When the amount is more than 3.5% by mass, the molten residue is generated in the vicinity of the solid solution limit and becomes a hard spot. Therefore, the amount of Fe added is 0.4% by mass to 3.5% by mass.

Ni contributes to the formation of intermetallic compounds and improves wear resistance. In addition, it will solidify in the parent phase and increase the strength of the parent phase. When Ni is less than 0.5% by mass, the mother phase strengthening by solid solution of Ni is insufficient, and if Ni exceeds 4.0% by mass, the effect corresponding to the cost cannot be obtained. Therefore, the addition amount of Ni is set to 0.5% by mass. 4.0% by mass.

Co helps to form intermetallic compounds and improves wear resistance. If it is less than 0.3% by mass, the ductility improvement by the spheroidization of the intermetallic compound cannot be exhibited, and the compound with Si is not sufficiently formed. When Co exceeds 2.0% by mass, the effect corresponding to the cost cannot be obtained. Therefore, the amount of Co added is set to 0.3% by mass to 2.0% by mass.

Mn contributes to the formation of intermetallic compounds and improves wear resistance. When the Mn is less than 1.0% by mass, the intermetallic compound is not sufficiently formed, and the abrasion resistance is deteriorated. In addition, when Mn exceeds 5.0% by mass, the formation of the acicular intermetallic compound is excessive, and the ductility is deteriorated. Therefore, the amount of addition of Mn is set to 1.0% by mass to 5.0% by mass.

Si forms an intermetallic compound with the above-mentioned Al, Ni, Fe, Co, and Mn, thereby improving wear resistance. When Si is less than 0.3% by mass, the intermetallic compound is not sufficiently formed, resulting in deterioration of abrasion resistance. When Si exceeds 3.5% by mass, a large amount of Fe, Mn, and Co are required to suppress solid solution in the mother phase, and a large amount of intermetallic compound is generated and crystallized to precipitate, resulting in a decrease in ductility. Therefore, the addition amount of Si is set at 0.3. Mass%~3.5% by mass.

More specifically, the present invention is to suppress the solid solution of Si in the matrix phase, and the γ phase precipitation due to high zinc equivalent does not occur. When Si is present at a certain ratio or more, it is dissolved in the matrix phase and contributes to growth. The γ phase precipitates, resulting in deterioration of strength, toughness, and impact resistance. Therefore, in order to suppress the solid solution of Si in the parent phase, it is necessary to satisfy the above formula (1).

The above formula (1) represents the mass % of Fe, Mn, and Co bonded to Si in the vicinity of 1% by mass, and when the right side of the left side is satisfied, the solid solution of Si in the parent phase does not occur. However, since the γ phase precipitates due to the balance with other contained elements, it is possible to satisfy the above formula (1) and satisfy the above formula (3), and maintain a balance with other elements in a certain amount without occurrence of γ phase precipitation. Composition. Further, the value calculated on the right side of the above formula (3) is hereinafter referred to as the parent phase zinc equivalent.

[Examples]

Specific embodiments of the invention are illustrated by the drawings.

The chemical composition of the sample to which the alloy of the present invention is associated is shown in Figures 2 and 3. No. 1 to 8 are examples in which all of the patent applications of the present invention are satisfied, and Nos. 9 to 17 are comparative examples (the unit of each component is mass%. The case where the formulas (1) and (3) are satisfied is represented by ○. The case of dissatisfaction is indicated by ×). These alloys were each melted using a high-frequency melting furnace, and two JIS H 5120 B metal molds were cast.

A JIS Z 2201 No. 4 tensile test piece was taken from a No. B metal mold, and a tensile test was carried out in accordance with JIS Z 2241. After the test, the jig portion of the tensile test piece was cut at 20 mm, embedded in a resin, and after mirror polishing, The optical microscope was used to observe the metal structure, and the presence or absence of the α, β, and γ phases was shown in Fig. 1.

Further, the zinc equivalent is obtained by Guillet's zinc equivalent coefficient according to the following formula (4).

Zinc equivalent (%) = (Y + Σ qt) / (X + Y + Σ qt) × 100 (% by mass) (4)

In the formula (4), X is the actual Cu content (% by mass) in the alloy, Y is the actual Zn content (% by mass) in the alloy, and q is an element content (% by mass) other than Cu or Zn. And t is a zinc equivalent coefficient of an element other than Cu or Zn. Further, the zinc equivalent coefficient of each element is Zn=1, Si=10, Al=6, Sn=2, Pb=1, Fe=0.9, Mn=0.5, and Ni=-1.3. Further, the zinc equivalent coefficient of Co is not clearly defined, but is calculated by 0.5 in the present specification.

In addition, in order to measure the impact resistance, a JIS Z 2202 V notch test piece (Fig. 8) was used among the alloys of No. 18 to 27 in Figs. 4 and 5, and Charpy was carried out at room temperature in accordance with JIS Z 2242. Rush test.

Examples of Nos. 18 to 22 shown in Figs. 4 and 5, and samples of Mn-Si (Patent Document 1) of Comparative Examples of Nos. 23 to 26 and CAC301 to CAC304 samples of Comparative Example No. 27, A high-frequency melting furnace was used, and it was produced using a JIS H 5120 B metal mold.

From these samples, the wear resistance and the resistance to fusion were evaluated.

The abrasion resistance is measured in a dry type by a large-scale wear test.

. Test piece shape 10t×20w×80L

. Target material SCM415 carburizing and quenching HRC56~59 (Figure 12)

. Test speed of 0.055, 0.101, 0.310, 0.512m/S 3 times each

. Load weight initial load 4.5N final load 67N

. Test distance 200m

The test piece is fixed with the surface having a large surface area as a test surface, and the object material is pressed against the vertical direction and rotated. The load is continuously increased, and the test distance is 67N when it reaches 200m. The evaluation is based on the change in weight of the test piece before and after the test, and the greater the wear amount, the worse the wear resistance is.

The refractory resistance evaluation was immersed in oil and evaluated by the Faville test.

. Test piece Figure 13

. Target material SCM415 carburizing and quenching HRC56~59 (Figure 14)

. Test speed 300rpm

. Test load 30kgf/s

. Oil Shell Turbo Oil T32

The test material is sandwiched by the object material, and the load is continuously increased from the side of the object material, and the needle is rotated.

The evaluation is the measurement of the amount of work (kgf.s) on the sample until the stage of the production of the melt, and is determined as the normal value. The smaller the Favie value, the worse the resistance to fusion is.

The results of the metal structure, the tensile test, and the Charpy test are shown in Figs. 1, 6, 7, 9, 10, and 11, and the results of the large-scale wear test and the law-dimensional test are shown in Figs. 15, 16, and 17.

It can be confirmed from Fig. 1 that the metal structure of the present embodiment is an Al-Fe-Mn-Si-Ni-Co intermetallic compound in the parent phase (α phase + β phase + γ phase or β phase). The crystals are precipitated and present a dispersed structure. In the case where the parent phase is the α phase + β phase, it is also confirmed that the Al—Fe—Mn—Si—Ni—Co intermetallic compound crystallizes and is dispersed, and is excellent as in the present embodiment. Wear resistance.

In Nos. 9 to 17 of Figs. 2 and 3, as shown in Fig. 1, a β phase + γ phase was observed. These comparative examples do not satisfy the formula (1) or the formula (3), and thus the parent phase becomes a β phase + γ phase structure. As a result, the alloy Nos. 16 and 17 which do not satisfy the formula (1) have a β phase and a γ phase, and thus the tensile strength and ductility are lower than those of No. 1 to 8. Further, since alloys No. 9 to 15 composed of the β phase + γ phase do not satisfy the formula (3), as shown in Figs. 9, 10 and 11, a decrease in various characteristics was observed, particularly in the stretching of Fig. 9. Among the strengths, a significant decrease was observed. From these results, it is understood that in order to secure a certain amount of mechanical properties, it is necessary to produce an alloy within the range satisfying the formulas (1) and (3).

From the above results, it is understood that when the matrix phase is a β phase + γ phase structure, the mechanical properties are deteriorated. Therefore, it is necessary to satisfy the formulas (1) and (3), and the wear characteristics of the sample prepared in the range satisfying these conditions are as shown in the figure. The results described in 15, 16, and 17.

15 and 16 are the results of the Daewoo wear test (wearing speed of 0.055 m/s, 0.101 m/s), and the wear ratios of the examples (No. 18 to 22) are compared with those of the comparative examples (No. 23 to 27). Less, it is considered to have excellent wear resistance.

Fig. 17 shows the results of the fare test, and this result also shows that the examples (No. 18 to 22) are superior in resistance to fusion resistance as compared with the comparative examples (No. 23 to 27).

From the above results, it is seen that the embodiment suppresses the solid solution of Si in the parent phase and balances with other elements. Although the zinc equivalent is 50% or more, the parent phase is not composed of the β phase + γ phase structure, so it is retained. A high-strength brass alloy with a certain amount of strength, toughness, and impact resistance, and excellent wear resistance. Therefore, the alloy of the present invention composed of these components is a material suitable for a sliding member such as a bushing or a bearing.

Claims (4)

An abrasion-resistant copper alloy characterized by containing Zn: 10 to 40%, Al: 2 to 9%, Fe: 0.4 to 3.5%, Ni: 0.5 to 4.0%, and Co: 0.3 by mass ratio. 2.0%, Mn: 1.0 to 5.0%, Si: 0.3 to 3.5%, the residual portion is composed of Cu and unavoidable impurities, and has an Al-Fe-Mn-Si-Ni-Co intermetallic compound dispersed in the α phase A tissue of at least one of +β phase, α phase + β phase + γ phase or β phase. For example, in the wear-resistant copper alloy of claim 1, wherein the mass ratio of Fe, Mn, Co and Si satisfies the following formula (1): [Number 1] 0.861 × Fe (% by mass) + 0.194 × Mn (mass %) + 0.487 × Co (% by mass) ≧ Si (% by mass). . . (1). The wear-resistant copper alloy according to claim 1, wherein the value obtained by the following formula (2) is substituted into the following formula (3), and the following formula (3) is satisfied. Here, the left side A ^X is a value obtained by substituting the content of any one of Cu, Sn, Pb, Zn, Al, or Ni into the X on the right side, and the element of the X substituted on the right side is superscripted as A ^{Cu , A Sn, A Pb, A} Zn, A Al or A ^Ni, The wear-resistant copper alloy according to claim 2, wherein the value obtained by the following formula (2) is substituted into the following formula (3), and the following formula (3) is satisfied: Here, the left side A ^X is a value obtained by substituting the content of any one of Cu, Sn, Pb, Zn, Al, or Ni into the X on the right side, and the element of the X substituted on the right side is superscripted as A ^Cu , A ^Sn , A ^Pb , A ^Zn , A ^Al or A ^Ni ,