WO2015000343A1

WO2015000343A1 - Aluminum-zinc high alloy and preparation method thereof, and heat treatment method

Info

Publication number: WO2015000343A1
Application number: PCT/CN2014/078920
Authority: WO
Inventors: 陈灿; 包宏旭; 闫振奇; 贾铁猛
Original assignee: 陈鑫
Priority date: 2013-07-03
Filing date: 2014-05-30
Publication date: 2015-01-08
Also published as: CN103290266A; CN103290266B

Abstract

An aluminum-zinc high alloy and preparation method thereof, and heat treatment method, the constituents of the alloy being: 31-33 wt.% of Al, 2-3 wt.% of Cu, 0.015-0.025 wt.% of Mg, and the balance being Zn; the method comprising: employing boron salt as a modificator during the alloy smelting process; maintaining a temperature of 355-375°C for 3-5 hours after casting; and then conducting water quenching and aging. The alloy has tensile strength of greater than 480 MPa, elongation of greater than 20%, and hardness of greater than HB 150 kgf/mm.

Description

High aluminum zinc alloy, manufacturing method thereof and heat treatment method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of preparation of metal materials, and more particularly to an alloy containing aluminum as a wear resistant material, and also relates to a method for producing the alloy and a method for heat treatment. Background technique

As a friction-reducing material, Al-Aluminium alloy gradually replaces the expensive Sn and Pb alloys, and then gradually replaces tin bronze with the shortage of copper resources. The high-alloy alloy has good mechanical properties and excellent casting process performance. The lower raw material cost and low melting energy consumption, no pollution to the environment and simple process have attracted more attention than the previous anti-wear materials (ZQSn6-6-3, ZQSn 1 0-1 alloy). Among them, Canadian scientists have developed the ZA12, ZA27 and ZA8 aluminum alloys, thus forming the current "ZA" series of high-alloy alloys.

However, after years of development, the performance indexes of the "ZA" series of high-alloy alloys are shown in Table 1. Among them, the strength of the aluminum alloy is up to 400-450 MPa, and the elongation is low, the toughness is poor, and it can only be used to manufacture the bearing bush. Abrasive material products such as bushings, and the strength, hardness, and toughness of the worm gears and nuts are insufficient. In particular, the ZA30 alloy mentioned in Yang Zhenzhen et al., “Material Heat Treatment Technology”, Vol. 37, No. 12, its performance index is basically equivalent to ZA27. Table 1 Mechanical properties of high aluminum alloy and tin bronze

As can be seen from the above, the tensile strength of the "ZA" series of high-alloy alloys does not exceed 450MPa, although the tensile strength of the high aluminum alloy can meet some of the requirements of low tensile strength, such as bearing bushes, bushings, etc., but for some occasions with higher strength requirements, these "ZA" series High aluminum alloys can no longer meet the actual needs. Therefore, it is necessary to provide a high-alloy alloy that can meet the requirements of high-strength occasions such as worm gears, nuts, and guide rails. Therefore, it is necessary to solve the problem of strength, hardness and toughness of the alloy. It is a very urgent need. Summary of the invention

In order to solve the above problems, the inventors have made the highest tensile strength of the high-alloy alloy after years of research, the ratio of the high-alloy alloy, the manufacturing process of the aluminum alloy, and the heat treatment process. It can reach 591.7 MPa, the elongation can reach 29.7%, and the hardness can reach HB172, which is significantly beyond the prior art. The technical solution adopted by the present invention is as follows:

A high-alloy alloy with a tensile strength of 480 MPa or more, including: AL: 31 - 33 (weight). /. , Cu: 2-3 (by weight) %, Mg: 0.015-0.025 (by weight) %, and the balance is Zn.

Further, the alloy has a tensile strength of 500 MPa or more, an elongation of 20% or more, and a hardness of HB 150 kgf/mm or more.

A method for manufacturing a high-alloy alloy having a tensile strength of 480 MPa or more, comprising the steps of: heating a graphite crucible to 400-500 ° C, adding a high-purity ingot to a graphite crucible, and melting the iso-purity ingot, The alloy ratio is added to the high-purity aluminum ingot, and the furnace temperature is heated to 600-700 ° C. After the high-purity aluminum ingot is melted, the AICu50 intermediate alloy is added according to the alloy ratio. After all the melting, the high-purity magnesium ingot is used according to the alloy ratio. After the aluminum foil is wrapped, it is pressed into the alloy liquid by a bell jar, and after melting, the bell jar is taken out, and after stirring, the boron salt is added to be spoiled, and then the ingot can be ingot to obtain the high aluminum alloy of the above composition. Further, it is allowed to stand still before stirring, and the static time is 15-30 minutes.

Further, high purity means that the purity of each raw material ingot is 99.99% or more.

Further, the boron salt is obtained by potassium fluoroborate or potassium fluoroborate and potassium fluorotitanate in a ratio of 1:1 at about 400 ° C for 2 hours. Among them, after the high-alloy alloy is obtained in the ingot, the high-alloy alloy is heat-treated at a heat treatment temperature of 355-375 ° C, a holding time of 3-5 hours, water quenching and aging at 80-10 CTC for 0.5-2 hours. A heat treatment method for a high-alloy alloy having a tensile strength of 480 MPa or more, comprising heat-treating a high-alloy alloy obtained after casting at a temperature of 355-375 ° C for a holding time of 3-5 hours, and water quenching at 80- Aging at 100 °C for 0.5-2 hours.

A high-alloy alloy with a tensile strength of 480 MPa or more, which is used for manufacturing worm gears, nuts, guide plates, bushings, bushings, and the like.

The composition of the high-alloy alloy with a tensile strength of 480 MPa or more includes: AL: 31 - 33 (weight). /. , Cu : 2-3 (by weight) %, Mg : 0.01 5-0.025 (by weight) %, and the balance is Zn. The alloy is produced by the above-described production method, and the alloy has a tensile strength of 500 MPa or more, an elongation of 20% or more, and a hardness of HB1 of 50 kgf/mm or more. Preferably, the tensile strength is 591.7 MPa, the elongation is 29.7%, and the hardness is H B172 kgf/mm or more. Compared with the closest ZA30 alloy in the prior art, the present invention achieves a tensile strength of 500 MPa or more, an elongation of 20% or more, and a hardness of HB1 50 kgf by a specific manufacturing process and a heat treatment process. /mm or more. The high-strength, high-toughness aluminum alloy can be applied to corresponding fields such as worm gears, nuts, guide plates, bushings, bushings, and the like. DRAWINGS

1 is a topographical view of an as-cast microstructure of an alloy obtained after casting of a high alumina alloy according to an embodiment of the present invention;

Fig. 2 is a view showing the microstructure of a high alumina alloy after heat treatment according to an embodiment of the present invention.

The structure was heat-treated at 360 °C by casting the high-alloy alloy at a temperature of 5 °C, water-quenched and aged at 90 °C for 1.5 hours.

detailed description

The high-alloy alloy of the present invention having a tensile strength of 480 MPa or more and the method for producing the same are described in detail below, but the description is merely exemplary and is not intended to limit the scope of the invention. Preparation example

First, the alloy composition of the high aluminum alloy prepared by the present invention is shown in Table 2 of Table 2.

Preparation method embodiment

Example 1

According to the alloy composition of ZA-TI600a alloy in Table 2, prepare high-purity (99.99%) aluminum ingot, high-purity (99.99%) ingot, high-purity (99.99%) magnesium ingot, and prepare AICu50 intermediate alloy, intermediate alloy in advance. The AICU50 is smelted in a graphite crucible by 50% by weight of high-purity aluminum and 50% by weight of electrolytic copper. Then, the graphite crucible is heated to 500 ° C, and the high-purity ingot is added into the graphite crucible. After the homogenization of the ingot is melted, the high-purity aluminum ingot is added according to the alloy ratio, and the furnace temperature is heated to 650 ° C until high purity. After the aluminum ingot is melted, the AICU50 master alloy is added according to the alloy ratio of ZA-TI600a. After all the melting, the high-purity magnesium ingot is wrapped with aluminum foil according to the alloy ratio, and then pressed into the alloy liquid with a bell jar, and the bell jar is taken out after melting. After the stirring, the boron salt is added, and the boron salt is heated by potassium fluoroborate and potassium fluorotitanate in a ratio of 1:1 at about 400 ° C for 2 hours. After the modification, the high aluminum alloy can be obtained by ingot casting. Its metallographic organization is shown in Figure 1. It can be seen from the figure that the as-cast microstructure of the alloy is mainly composed of primary α ( A 1 ) dendrites, dendritic edge α ( A 1 ) + η ( Ζη ) eutectoids, and grain boundaries from β (ΖηΑ Ι) + η (Ζη) + ε (CuZn ₄ ) ternary eutectic composition. It can be seen from Fig. 1 that the dendrite center is a white α phase, the dendrite edge is a gray (α + η ) eutectoid, and the grain boundary is a black (β + η + ε ) ternary eutectic, black total The crystal is dotted with a white ε phase. After the preparation of the alloy of ZA-TI600a is completed, the alloy may be heat-treated subsequently or directly. The heat treatment process includes: a high-alloy alloy obtained after casting or a high-alloy alloy obtained The heat treatment was carried out at 360 ° C for 5 hours, water quenched and aged at 0.5 ° C for 1.5 hours to complete the finished alloy. Its metallographic organization is shown in Figure 2. It can be seen from Fig. 2 that the matrix of the alloy structure is mainly composed of (α + η ) eutectoids, the primary phase α is surrounded by the eutectoid (α + η ), the structure tends to be uniformly refined, and there are black and white. The granules precipitated.

Example 2

According to the alloy composition of ZA-TI600b alloy in Table 2, prepare high-purity (99.99%) aluminum ingot, high-purity (99.99%) ingot, high-purity (99.99%) magnesium ingot, and prepare AICu50 intermediate alloy, intermediate alloy in advance. The AICU50 is smelted in a graphite crucible by 50% by weight of high-purity aluminum and 50% by weight of electrolytic copper. Then, the graphite crucible is heated to 450 ° C, and the high-purity ingot is added into the graphite crucible. After the homogenous pure ingot is melted, the high-purity aluminum ingot is added according to the alloy ratio, and the furnace temperature is heated to 700 ° C, to be high-purity. After the aluminum ingot is melted, the AICU50 intermediate alloy is added according to the alloy ratio of ZA-TI600b. After all the melting, the high-purity magnesium ingot is wrapped with aluminum foil according to the alloy ratio, and then pressed into the alloy liquid with a bell jar, and the bell jar is taken out after melting. After the addition of the boron salt potassium fluoroborate by stirring, the ingot can be ingot to obtain the above-mentioned high aluminum alloy. After the preparation of the alloy of ZA-TI600b is completed, the alloy may be heat-treated subsequently or directly. The heat treatment process includes: heat-treating the high-alloy alloy obtained after casting or heat-treating the obtained high-alloy alloy at 375 ° C, keeping warm The finished alloy was completed in 3 hours, water quenched and aged at 100 ° C for 1 hour.

Performance analysis

ZA-TI600a, ZA-TI600b prepared above (the two alloys are given the mark high aluminum base)

The mechanical properties of ZA6005 alloy) were tested by the Mechanical Industry Product Quality Supervision and Inspection Center (Shenyang). The mechanical properties of the test were as shown in Table 3. Table 3 Mechanical properties of high alumina alloy and control alloy Tensile strength

Elongation % Hardness HB Friction coefficient

MFa ZA-TI600a 5S)L7 29.7 172 0.03-0.05

ZA~TI6()0b 589 28.5 169 0.03-0.05

ZQSn6"6-3 180-220 6 68 0,09

ZQSii lO~l 220-250 3-5 80-90 0.08

Inch

o

o 8-1 1 1 10 120 0.03-0.07

ZA303A 380-420 15-18 120 0.05 According to Table 3, it can be seen that the tensile strength of ZA-TI600a and ZA-TI600b obtained by the above preparation method reaches 480 MPa or more, which far exceeds several kinds of antifriction alloys in the prior art. Corresponding values; the elongation rate is 29.7%, which is significantly better than the alloys in the prior art, and the hardness is also above HB150. Referring to the alloy structure of Fig. 1 and Fig. 2, Fig. 1 is the alloy structure of ZAT600 alloy after heat treatment mainly from primary α ( ΑΙ ) dendrites, dendritic edge α ( ΑΙ ) + η ( Zn ) eutectoids, grain boundaries It is composed of β(ΖηΑΙ)+η(Ζη)+ε(〇υΖη ₄ ) ternary eutectic. It can be seen from Fig. 1 (a) that the dendrite center is a white α phase, the dendrite edge is a gray (α+η) eutectoid, and the grain boundary is a black (β+η+ε) ternary eutectic. Basically composed mainly of (α+η) eutectoids, the primary phase α is surrounded by eutectoids (α+η). As the aging time prolongs, the tissue tends to be uniformly refined, and black and white granules are precipitated. It is found from Fig. 2 that a small amount of Cu can be dissolved in both the α phase and the β phase at room temperature, and an appropriate amount (2.0% - 2.5%) of the copper-rich phase is dispersed in the microstructure of the alloy, which can effectively block dislocations. Move, thus increasing strength. The white matter precipitated from the η phase (Zn) during aging is mainly the ε (CuZn ₄ ) phase. The ε phase is a hard and brittle phase in the alloy structure. As the aging time increases, more and more ε phase (CuZn ₄ ) precipitates from the η phase (Zn). The alloy structure is further refined to simultaneously increase the tensile strength and elongation of the alloy.

The high aluminum alloy of the invention, through the exploration of the ratio, the preparation process and the heat treatment process, makes the comprehensive performance of the alloy obtained by the preparation process and/or the heat treatment process greatly exceeds the comprehensive performance of the alloy in the prior art. The index has a wide range of applications, such as worm gears, nuts, rail plates, bushings, bushings and other fields. While the invention has been described and illustrated in detail hereinabove, it should be understood that the function of the present invention is not intended to be limited to the spirit of the invention.

Claims

claims

1. A high-aluminum alloy with a tensile strength of more than 480Mpa. Its composition includes: AL: 31-33 (weight). /. , Cu: 2-3 (weight) %, Mg: 0.01 5-0.025 (weight) %, the balance is Zn.

2. The high-aluminum alloy according to claim 1, wherein the tensile strength of the alloy is more than 500MPa, the elongation is more than 20%, and the hardness HB1 is more than 50kgf/mm.

3. A method for manufacturing a high-aluminum alloy with a tensile strength of more than 480Mpa, including the following steps: heating the graphite crucible to 400-500 °C, adding high-purity aluminum ingots to the graphite crucible, and waiting for the high-purity aluminum ingots to melt. , add high-purity aluminum ingots according to the alloy ratio, heat the furnace temperature to 600-700 °C, and after the high-purity aluminum ingots melt, add AICu50 master alloy according to the alloy ratio. After all melts, add high-purity magnesium according to the alloy ratio. After the ingot is wrapped with aluminum foil, it is pressed into the alloy liquid with a bell jar. After melting, the bell jar is taken out. After stirring, boron salt is added to modify the ingot and the ingot is poured to obtain a high-aluminum alloy. Its composition includes: AL: 31 -33 (weight )%, Cu: 2-3 (weight)%, Mg: 0.01 5-0.025 (weight)%, the balance is Zn.

4. The method as claimed in claim 1, wherein staticization is performed before stirring, and the static time is 15-30 minutes.

5. The method of claim 4, wherein high purity means that the purity of each raw material ingot is above 99.99%.

6. The method according to any one of claims 3 to 5, wherein the boron salt is potassium fluoroborate or potassium fluoroborate and potassium fluotitanate are obtained by heating at about 400°C for 2 hours in a 1:1 ratio. .

7. The method according to any one of claims 3-5, wherein after the high-aluminum alloy is obtained by pouring the ingot, the high-aluminum alloy is subjected to heat treatment, the heat treatment temperature is between 355-375°C, and the holding time is 3- 5 hours, water quenching and aging at 80-10CTC for 0.5-2 hours.

8. A heat treatment method for a high-aluminum alloy with a tensile strength of more than 480Mpa, including heat-treating the high-aluminum alloy obtained after casting at 355-375°C, holding for 3-5 hours, and quenching with water. 80-10CTC aging for 0.5-2 hours, the alloy composition includes: AL: 31-33 (weight) %, Cu: 2-3 (weight) %, Mg: 0.01 5-0.025 (weight) %, the balance is Zn .

9. Use of the high-aluminum alloy of claim 1 for manufacturing worm gears, nuts, guide rail plates, bearing bushes, bushings, etc.

10. Use of the high-aluminum alloy according to claim 9, wherein the alloy is manufactured by any of the manufacturing methods of claims 3-7, and the tensile strength of the alloy is 500 MPa or more, and the elongation is 20 % or above, hardness HB1 50kgf/mm or above.