A rare earth-containing Cu-Al-C master alloy and its preparation method

Abstract

The present invention discloses a rare earth-containing Cu-Al-C master alloy and its preparation method, belonging to the technical field of copper alloys. The elemental composition of the alloy is as follows by mass percentage: Al: 10.0 - 30.0%, C: 0.5 - 5.5%, mixed rare earth: 0.1 - 0.5%, wherein the mixed rare earth is composed of three of lanthanum, cerium, neodymium, yttrium, and scandium, and the balance is copper. The preparation steps of the alloy of the present invention are as follows: First, Al powder and Al4C3 powder are evenly mixed and then put into a steel mold. After heating to 600 °C, it is hot-pressed into shape and kept warm for 5 minutes to make an ingot blank. Then, pure Cu is put into a vacuum induction furnace to be heated and melted, and then a copper-rare earth master alloy and an Al-Al4C3 ingot blank are added. After all are melted and homogenized, it is cast into a Cu-Al-C alloy ingot containing mixed rare earth. Then, it is put into a vacuum heat treatment furnace and heated to 750 - 950 °C and kept warm for 2 hours for homogenization treatment. Finally, it is put into an extrusion die and heated to 750 - 900 °C for extrusion to obtain the final alloy bar. The master alloy of the present invention is used for smelting carbon-containing copper alloys and also has certain purification effects such as impurity removal and deoxidation.

Description

Technical Field

[0001] The present invention relates to a rare earth-containing Cu-Al-C master alloy and a preparation method thereof, belonging to the technical field of copper alloys. Background Art

[0002] When melting and preparing copper alloys containing high melting point chemical elements, in order to promote the melting and uniform dispersion of the high melting point element, an intermediate alloy formed by it and copper is usually added to the melt, and an ingot is obtained after casting; on the other hand, when melting and preparing copper alloys containing lower melting point or more active chemical elements, in order to minimize the loss of the low melting point element, an intermediate alloy formed by it and copper is also added to the melt, and an ingot is obtained after solidification. At present, the types of binary copper master alloys are extremely rich, such as Cu-Ti, Cu-Si, Cu-Zr, etc. containing high melting point elements, and Cu-Mg, Cu-P, Cu-Ce, Cu-La, etc. containing low melting point or more active elements; however, due to the high melting point of the C element and the immiscibility of Cu and the C element, if C is directly added to the copper melt, it is difficult to melt and disperse, and it can only be added in the form of a C-containing intermediate alloy, while Cu and C cannot form an intermediate alloy. Summary of the Invention

[0003] In order to overcome the above deficiencies, the purpose of the present invention is to provide a rare earth-containing Cu-Al-C master alloy and a preparation method thereof, which are convenient for the melting and preparation of C-containing copper alloys.

[0004] The element composition of the alloy described in the present invention is as follows:

[0005] Al: 10.0 - 30.0%, C: 0.5 - 5.5%, mixed rare earth: 0.1 - 0.5%, all are mass percentages, wherein the mixed rare earth is three of lanthanum, cerium, neodymium, yttrium, and scandium, and the balance is copper.

[0006] The preparation method of the alloy described in the present invention includes the following steps:

[0007] (1) Uniformly mix Al powder and Al4C3 powder according to a certain mass ratio, put them into a steel mold, heat to 600°C, hot press and form with a hydraulic press, and keep warm for 5 minutes to prepare an Al-Al4C3 ingot blank;

[0008] (2) Cut the Al-Al4C3 ingot blank into small pieces of 5mm×5mm×5mm;

[0009] (3) Put pure Cu into a vacuum induction furnace, heat to 1200°C, melt it, add three of the Cu-La, Cu-Ce, Cu-Nd, Cu-Y, and Cu-Sc master alloys and the small pieces of Al-Al4C3 ingot blank, and pour and cast into a rare earth-containing Cu-Al-C alloy ingot after all are melted and uniform;

[0010] (4) Put the rare earth-containing Cu-Al-C alloy ingot into a vacuum heat treatment furnace, heat it to 750-950 °C, and hold for 2 h for homogenization treatment;

[0011] (5) Put the homogenized alloy ingot into an extrusion die, heat it to 750-900 °C, and extrude it according to an extrusion ratio of 9:1 to obtain a Cu-Al-C master alloy rod containing mixed rare earths.

[0012] The master alloy of the present invention has the following beneficial effects:

[0013] (1) The master alloy contains C element and is easy to melt, which is convenient to add to the melt and uniformly disperse;

[0014] (2) It contains a variety of rare earth elements, and has certain purification effects such as impurity removal and deoxidation after being added to the melt;

[0015] (3) The contained Al element can improve the strength and corrosion resistance of the alloy;

[0016] (4) The cost is low, it is easy to prepare, and the contents and ratios of Al element and C element can be adjusted according to needs. Specific embodiments

[0017] Example 1

[0018] This example gives a preparation method of a Cu-10Al-1C master alloy rod containing 0.2% mixed rare earths, including the following steps:

[0019] (1) Uniformly mix Al powder and Al4C3 powder according to the required mass ratio, put them into a steel mold, heat to 600 °C, and then hot press and form with a hydraulic press and hold for 5 min to prepare an Al-Al4C3 ingot blank;

[0020] (2) Cut the Al-Al4C3 ingot blank into small pieces of 5 mm×5 mm×5 mm;

[0021] (3) Put pure Cu into a vacuum induction furnace and heat to 1200 °C. After melting, add Cu-La, Cu-Ce, Cu-Nd master alloys and Al-Al4C3 ingot blanks according to the required mass. After all are melted and homogenized, pour them into a Cu-10Al-1C alloy ingot containing mixed rare earths;

[0022] (4) Put the rare earth-containing Cu-10Al-1C alloy ingot into a vacuum heat treatment furnace, heat to 950 °C, and hold for 2 h for homogenization treatment;

[0023] (5) Put the homogenized alloy ingot into an extrusion die, heat to 900 °C, and extrude it according to an extrusion ratio of 9:1 to obtain a Cu-10Al-1C master alloy rod containing mixed rare earths.

[0024] Example 2

[0025] This embodiment provides a method for preparing a Cu-15Al-2C master alloy rod containing 0.3% mixed rare earths, which includes the following steps:

[0026] (1) Uniformly mix Al powder and Al4C3 powder according to the required mass ratio, put them into a steel mold, heat to 600 °C, then hot press and form with a hydraulic press and keep warm for 5 minutes to prepare an Al-Al4C3 ingot blank;

[0027] (2) Cut the ingot blank into small pieces of 5 mm × 5 mm × 5 mm;

[0028] (3) Put pure Cu into a vacuum induction furnace and heat to 1200 °C. After melting, add Cu-Ce, Cu-Nd, Cu-Y master alloys and the Al-Al4C3 ingot blank according to the required mass. After all are melted and homogenized, pour them into a Cu-15Al-2C alloy ingot containing mixed rare earths;

[0029] (4) Put the Cu-15Al-2C alloy ingot containing rare earths into a vacuum heat treatment furnace, heat to 900 °C and keep warm for 2 hours for homogenization treatment;

[0030] (5) Put the homogenized alloy ingot into an extrusion die, heat to 850 °C and extrude according to an extrusion ratio of 9:1 to obtain a Cu-15Al-2C master alloy rod containing mixed rare earths.

[0031] Example 3

[0032] This embodiment provides a method for preparing a Cu-25Al-3C master alloy rod containing 0.5% mixed rare earths, which includes the following steps:

[0033] (1) Uniformly mix Al powder and Al4C3 powder according to the required mass ratio, put them into a steel mold, heat to 600 °C, then hot press and form with a hydraulic press and keep warm for 5 minutes to prepare an Al-Al4C3 ingot blank;

[0034] (2) Cut the Al-Al4C3 ingot blank into small pieces of 5 mm × 5 mm × 5 mm;

[0035] (3) Put pure Cu into a vacuum induction furnace and heat to 1200 °C. After melting, add Cu-La, Cu-Y, Cu-Sc master alloys and the Al-Al4C3 ingot blank according to the required mass. After all are melted and homogenized, pour them into a Cu-25Al-3C alloy ingot containing mixed rare earths;

[0036] (4) Put the Cu-25Al-3C alloy ingot containing rare earths into a vacuum heat treatment furnace, heat to 850 °C and keep warm for 2 hours for homogenization treatment;

[0037] (5) The homogenized alloy ingot is placed in an extrusion die and heated to 800 °C, and then extruded at an extrusion ratio of 9:1 to obtain a Cu-25Al-3C master alloy rod containing mixed rare earths.

Claims

1. A preparation method of a rare earth-containing Cu-Al-C master alloy, characterized in that, It includes the following steps: (1) Uniformly mix Al powder and Al4C3 powder in a certain mass ratio, put them into a steel mold, heat to 600 °C, hot press and form with a hydraulic press and keep warm for 5 min, then cool to room temperature and take out the ingot blank; (2) Cut the Al-Al4C3 ingot blank into small pieces of 5 mm × 5 mm × 5 mm; (3) Put pure Cu into a vacuum induction furnace and heat to 1200 °C, add three kinds of Cu-La, Cu-Ce, Cu-Nd, Cu-Y, Cu-Sc master alloys and small pieces of Al-Al4C3 ingot blank after melting, and pour and cast into a Cu-Al-C alloy ingot containing mixed rare earths after all are melted and homogenized; (4) Put the Cu-Al-C alloy ingot containing rare earths into a vacuum heat treatment furnace, heat to 750-950 °C and keep warm for 2 h for homogenization treatment; (5) Put the homogenized alloy ingot into an extrusion die, heat to 750-900 °C and extrude according to an extrusion ratio of 9:1 to obtain a Cu-Al-C master alloy rod containing mixed rare earths; For the Cu-Al-C master alloy containing rare earths, its element composition is as follows by mass percentage: Al: 10.0-30.0%, C: 0.5-5.5%, mixed rare earths: 0.1-0.5%, where the mixed rare earths are three of lanthanum, cerium, neodymium, yttrium, and scandium, and the balance is copper.