METHOD FOR PREVENTING CRACKING OF NICKEL-BASED SUPERALLOY FABRICATED BY SELECTIVE LASER MELTING

Abstract

A method for preventing cracking of nickel-based superalloy fabricated by selective laser melting (SLM) belongs to the field of additive manufacturing (AM). The method of preparing an as-built part with a high density, no crack defects, and good mechanical properties includes: reducing the content of elements Zr and B forming low melting point phase in a nickel-based superalloy, adjusting the total content of Al and Ti in the alloy to 4.5 wt % or below, and combining with the control of special SLM process parameters. The new method has the advantages of a reasonable component design, a simple preparation process, and good performance of the as-built part, and therefore is suitable for large-scale application.

Claims

1. A method for preventing cracking of a nickel-based superalloy fabricated by selective laser melting (SLM), comprising: step 1: adjustment of alloy composition: reducing a content of Zr and a content of B in the nickel-based superalloy, and adjusting a total content of Al and Ti in the nickel-based superalloy to 4.5 wt % or below, to obtain a required nickel-based superalloy powder; and step 2: SLM building: preparing an as-built part under a protective atmosphere by an SLM building process using the required nickel-based superalloy powder as a raw material.

2. The method according to claim 1, wherein in the step 1, the content of Zr in the required nickel-based superalloy powder is 0%.

3. The method according to claim 1, wherein in the step 1, the content of B in the required nickel-based superalloy powder is 0-0.02 wt %.

4. The method according to claim 1, wherein in the SLM building process, a substrate heating temperature is controlled to 150° C., a rotation angle between scanning layers is controlled to 67.5°, a laser input power is controlled to 300-350 W, preferably 315-335 W, a scanning speed is controlled to 750-850 mm/s, preferably 785-815 mm/s, a scanning space is controlled to 0.11-0.13 mm, and a powder layer thickness is controlled to 30-40 μm.

5. The method according to claim 1, wherein in the SLM building process, a laser spot diameter is controlled to 0.12 mm; and in the SLM building process, a snake scanning strategy is used for laser scanning.

6. The method according to claim 1, wherein in the step 2, the required nickel-based superalloy powder is prepared by argon atomization or by plasma rotating electrode process (PREP).

7. The method according to claim 1, wherein in the step 2, the protective atmosphere is an argon atmosphere.

8. The method according to claim 1, wherein the required nickel-based superalloy powder comprises the following components in percentage by mass: Co: 20.6 wt %; Cr: 13.0 wt %; Mo: 3.8 wt %; W: 2.1 wt %; Al: 2.0 wt %; Ti: 2.5 wt %; Ta: 2.4 wt %; Nb: 0.9 wt %; Zr: 0 wt %; B: 0.01 wt %; C: 0.04 wt %; and Ni: the balance; the required nickel-based superalloy powder is prepared by argon atomization, and is sieved to obtain powder suitable for the SLM building; and the SLM building is used, a substrate heating temperature is adjusted to 150° C., a rotation angle between scanning layers is set to 67°, a laser input power is set to 325 W, a scanning speed is set to 800 mm/s, a scanning space is set to 0.12 mm, a powder layer thickness is set to 30 μm, a laser spot diameter is selected as 0.12 mm, a snake scanning strategy is selected for laser scanning, and after argon gas is introduced, printing is started, to obtain an as-built part with a density of 99.35%, no cracks, and a tensile strength of 1145 MPa at room temperature on an X-Y plane.

9. The method according to claim 1, wherein the required nickel-based superalloy powder comprises the following components in percentage by mass: Co: 8.5 wt %; Cr: 16 wt %; Mo: 1.75 wt %; W: 2.6 wt %; Al: 2.0 wt %; Ti: 2.5 wt %; Ta: 1.75 wt %; Nb: 0.9 wt %; Zr: 0 wt %; B: 0.01 wt %; C: 0.11 wt %; and Ni: the balance; the required nickel-based superalloy powder is prepared by argon atomization, and is sieved to obtain powder suitable for the SLM building; and the SLM building is used, a substrate heating temperature is adjusted to 150°C., a rotation angle between scanning layers is set to 67°, a laser input power is set to 300 W, a scanning speed is set to 750 mm/s, a scanning space is set to 0.12 mm, a powder layer thickness is set to 30 μm, a laser spot diameter is selected as 0.12 mm, a snake scanning strategy is selected for laser scanning, and after argon gas is introduced, printing is started, to obtain an as-built part with a density of 99.28%, no cracks, and a tensile strength of 1127 MPa at room temperature on an X-Y plane.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

Example 1

[0055] (1) A precipitation strengthened Rene 104 nickel-based superalloy included the following components in percentage by mass: [0056] Co: 20.6 wt %; [0057] Cr: 13.0 wt %; [0058] Mo: 3.8 wt %; [0059] W: 2.1 wt %; [0060] Al: 3.4 wt %; [0061] Ti: 3.9 wt %; [0062] Ta: 2.4 wt %; [0063] Nb: 0.9 wt %; [0064] Zr: 0.05 wt %; [0065] B: 0.03 wt %; [0066] C: 0.04 wt %; and [0067] Ni: the balance.

[0068] The contents of Zr, B, Al, and Ti in the Rene 104 nickel-based superalloy were adjusted to obtain the alloy composition including the following components in percentage by mass: [0069] Co: 20.6 wt %; [0070] Cr: 13.0 wt %; [0071] Mo: 3.8 wt %; [0072] W: 2.1 wt %; [0073] Al: 2.0 wt %; [0074] Ti: 2.5 wt %; [0075] Ta: 2.4 wt %; [0076] Nb: 0.9 wt %; [0077] Zr: 0 wt %; [0078] B: 0.01 wt %; [0079] C: 0.04 wt %; and [0080] Ni: the balance.

[0081] The nickel-based superalloy powder was prepared by argon atomization, and was sieved to obtain the powder suitable for SLM building (where the particle size of the nickel-based superalloy powder suitable for SLM building is 15-53 μm).

[0082] (2) The SLM building was used, a substrate heating temperature was adjusted to 150° C., a rotation angle between scanning layers was set to 67°, a laser input power was set to 325 W, a scanning speed was set to 800 mm/s, a scanning space was set to 0.12 mm, a powder layer thickness was set to 30 μm, a laser spot diameter of 0.12 mm was selected, a snake scanning strategy was selected for laser scanning. After argon gas was introduced, printing was started, the as-built part was a cubic block with a size of 10×10×10 mm. After the printing was completed, the as-built part was separated from the substrate.

[0083] The as-built part obtained by the foregoing steps has a density of 99.35% and no cracks, and has a tensile strength of 1145 MPa at room temperature on an X-Y plane.

Comparative Example 1

[0084] (1) A Rene 104 nickel-based superalloy powder was prepared by argon atomization, and was sieved to obtain the powder suitable for SLM building (where the particle size of the nickel-based superalloy powder suitable for SLM building is 15-53 μm).

[0085] (2) The SLM building was used, a substrate heating temperature was adjusted to 150° C., a rotation angle between scanning layers was set to 67°, a laser input power was set to 350 W, a scanning speed was set to 800 mm/s, a scanning space was set to 0.12 mm, a powder layer thickness was set to 30 μm, a laser spot diameter of 0.12 mm was selected, a snake scanning strategy was selected for laser scanning. After argon gas was introduced, printing was started, and the as-built part was a cubic block with a size of 10×10×10 mm. After the printing was completed, the as-built part was separated from the substrate.

[0086] The as-built part obtained by the foregoing steps has a density of 97.35% and a large quantity of micro-cracks, and has a tensile strength of 834 MPa at room temperature on an X-Y plane.

Comparative Example 2

[0087] (1) The contents of B and Zr in the Rene 104 nickel-based superalloy were adjusted to obtain the alloy composition including the following components in percentage by mass: [0088] Co: 20.6 wt %; [0089] Cr: 13.0 wt %; [0090] Mo: 3.8 wt %; [0091] W: 2.1 wt %; [0092] Al: 3.4 wt %; [0093] Ti: 3.9 wt %; [0094] Ta: 2.4 wt %; [0095] Nb: 0.9 wt %; [0096] Zr: 0 wt %; [0097] B: 0.01 wt %; [0098] C: 0.04 wt %; and [0099] Ni: the balance.

[0100] The nickel-based superalloy powder was prepared by argon atomization, and was sieved to obtain the powder suitable for SLM building (where the particle size of the nickel-based superalloy powder suitable for SLM building is 15-53 μm).

[0101] (2) The SLM building was used, a substrate heating temperature was adjusted to 150° C., a rotation angle between scanning layers was set to 67°, a laser input power was set to 325 W, a scanning speed is set to 800 mm/s, a scanning space was set to 0.12 mm, a powder layer thickness was set to 30 μm, a laser spot diameter of 0.12 mm was selected, a snake scanning strategy was selected for laser scanning. After argon gas was introduced, printing was started, and the as-built part was a cubic block with a size of 10×10×10 mm. After the printing was completed, the as-built part was separated from the substrate.

[0102] The as-built part obtained by the foregoing steps has a density of 98.65% and a small quantity of micro-cracks, and has a tensile strength of 915 MPa at room temperature on an X-Y plane.

Comparative Example 3

[0103] (1) The contents of Al and Ti in the Rene 104 nickel-based superalloy were adjusted to obtain the alloy composition including the following components in percentage by mass: [0104] Co: 20.6 wt %; [0105] Cr: 13.0 wt %; [0106] Mo: 3.8 wt %; [0107] W: 2.1 wt %; [0108] Al: 2.0 wt %; [0109] Ti: 2.5 wt %; [0110] Ta: 2.4 wt %; [0111] Nb: 0.9 wt %; [0112] Zr: 0.05 wt %; [0113] B: 0.03 wt %; [0114] C: 0.04 wt %; and [0115] Ni: the balance.

[0116] The nickel-based superalloy powder was prepared by argon atomization, and was sieved to obtain the powder suitable for SLM building (where the particle size of the nickel-based superalloy powder suitable for SLM building is 15-53 μm).

[0117] (2) The SLM building was used, a substrate heating temperature was adjusted to 150° C., a rotation angle between scanning layers was set to 67°, a laser input power was set to 325 W, a scanning speed was set to 800 mm/s, a scanning space was set to 0.12 mm, a powder layer thickness was set to 30 μm, a laser spot diameter of 0.12 mm was selected, a snake scanning strategy was selected for laser scanning. After argon gas was introduced, printing was started, and the as-built part was a cubic block with a size of 10×10×10 mm. After the printing was completed, the as-built part was separated from the substrate.

[0118] The as-built part obtained by the foregoing steps has a density of 98.85% and a small quantity of micro-cracks, and has a tensile strength of 986 MPa at room temperature on an X-Y plane.

Example 2

[0119] (1) A precipitation strengthened Inconel 738LC nickel-based superalloy included the following components in percentage by mass: [0120] Co: 8.5 wt %; [0121] Cr: 16 wt %; [0122] Mo: 1.75 wt %; [0123] W: 2.6 wt %; [0124] Al: 3.4 wt %; [0125] Ti: 3.4 wt %; [0126] Ta: 1.75 wt %; [0127] Nb: 0.9 wt %; [0128] Zr: 0.06 wt %; [0129] B: 0.01 wt %; [0130] C: 0.11 wt %; and [0131] Ni: the balance.

[0132] The contents of Zr, B, Al, and Ti in the Inconel 738LC nickel-based superalloy were adjusted to obtain the alloy composition including the following components in percentage by mass: [0133] Co: 8.5 wt %; [0134] Cr: 16 wt %; [0135] Mo: 1.75 wt %; [0136] W: 2.6 wt %; [0137] Al: 2.0 wt %; [0138] Ti: 2.5 wt %; [0139] Ta: 1.75 wt %; [0140] Nb: 0.9 wt %; [0141] Zr: 0 wt %; [0142] B: 0.01 wt %; [0143] C: 0.11 wt %; and [0144] Ni: the balance.

[0145] The nickel-based superalloy powder was prepared by argon atomization, and was sieved to obtain the powder suitable for SLM building (where the particle size of the nickel-based superalloy powder suitable for SLM building is 15-53 μm).

[0146] (2) The SLM building was used, a substrate heating temperature was adjusted to 150° C., a rotation angle between scanning layers was set to 67°, a laser input power was set to 300 W, a scanning speed was set to 750 mm/s, a scanning space was set to 0.12 mm, a powder layer thickness was set to 30 μm, a laser spot diameter of 0.12 mm was selected, a snake scanning strategy was selected for laser scanning. After argon gas was introduced, printing was started, and the as-built part was a cubic block with a size of 10×10×10 mm. After the printing was completed, the as-built part was separated from the substrate.

[0147] The as-built part obtained by the foregoing steps has a density of 99.28% and no cracks, and has a tensile strength of 1127 MPa at room temperature on an X-Y plane.

Comparative Example 4

[0148] (1) The Inconel 738LC nickel-based superalloy powder was prepared by argon atomization, and was sieved to obtain the powder suitable for SLM building (where the particle size of the nickel-based superalloy powder suitable for SLM building is 15-53 μm).

[0149] (2) The SLM building was used, a substrate heating temperature was adjusted to 150° C., a rotation angle between scanning layers was set to 67°, a laser input power was set to 300 W, a scanning speed was set to 750 mm/s, a scanning space was set to 0.12 mm, a powder layer thickness was set to 30 μm, a laser spot diameter of 0.12 mm was selected, a snake scanning strategy was selected for laser scanning. After argon gas was introduced, printing was started, and the as-built part was a cubic block with a size of 10×10×10 mm. After the printing was completed, the as-built part was separated from the substrate.

[0150] The as-built part obtained by the foregoing steps has a density of 97.56% and a large quantity of micro-cracks, and has a tensile strength of 864 MPa at room temperature on an X-Y plane.

Comparative Example 5

[0151] (1) The contents of B and Zr in the Inconel 738LC nickel-based superalloy were adjusted to obtain the alloy composition including the following components in percentage by mass: [0152] Co: 8.5 wt %; [0153] Cr: 16 wt %; [0154] Mo: 1.75 wt %; [0155] W: 2.6 wt %; [0156] Al: 3.4 wt %; [0157] Ti: 3.4 wt %; [0158] Ta: 1.75 wt %; [0159] Nb: 0.9 wt %; [0160] Zr: 0 wt %; [0161] B: 0.01 wt %; [0162] C: 0.11 wt %; and [0163] Ni: the balance.

[0164] The nickel-based superalloy powder was prepared by argon atomization, and was sieved to obtain the powder suitable for SLM building (where the particle size of the nickel-based superalloy powder suitable for SLM building is 15-53 μm).

[0165] (2) The SLM building was used, a substrate heating temperature was adjusted to 150° C., a rotation angle between scanning layers was set to 67°, a laser input power was set to 300 W, a scanning speed was set to 750 mm/s, a scanning space was set to 0.12 mm, a powder layer thickness was set to 30 μm, a laser spot diameter of 0.12 mm was selected, a snake scanning strategy was selected for laser scanning. After argon gas was introduced, printing was started, and the as-built part was a cubic block with a size of 10×10×10 mm. After the printing was completed, the as-built part was separated from the substrate.

[0166] The as-built part obtained by the foregoing steps has a density of 98.25% and a small quantity of micro-cracks, and has a tensile strength of 895 MPa at room temperature on an X-Y plane.

Comparative Example 6

[0167] (1) The contents of Al and Ti in the Inconel 738LC nickel-based superalloy were adjusted to obtain the alloy composition including the following components in percentage by mass: [0168] Co: 8.5 wt %; [0169] Cr: 16 wt %; [0170] Mo: 1.75 wt %; [0171] W: 2.6 wt %; [0172] Al: 2.0 wt %; [0173] Ti: 2.5 wt %; [0174] Ta: 1.75 wt %; [0175] Nb: 0.9 wt %; [0176] Zr: 0.06 wt %; [0177] B: 0.01 wt %; [0178] C: 0.11 wt %; and [0179] Ni: the balance.

[0180] The nickel-based superalloy powder was prepared by argon atomization, and was sieved to obtain the powder suitable for SLM building (where the particle size of the nickel-based superalloy powder suitable for SLM building is 15-53 μm).

[0181] (2) The SLM building was used, a substrate heating temperature was adjusted to 150° C., a rotation angle between scanning layers was set to 67°, a laser input power was set to 300 W, a scanning speed was set to 750 mm/s, a scanning space was set to 0.12 mm, a powder layer thickness was set to 30 μm, a laser spot diameter of 0.12 mm was selected, a snake scanning strategy was selected for laser scanning. After argon gas was introduced, printing was started, and the as-built part was a cubic block with a size of 10×10×10 mm. After the printing was completed, the as-built part was separated from the substrate.

[0182] The as-built part obtained by the foregoing steps has a density of 98.78% and a small quantity of micro-cracks, and has a tensile strength of 915 MPa at room temperature on an X-Y plane.

[0183] It can be seen from the examples and the comparative examples that the present disclosure can obtain a product with excellent performance only through the collaboration of various condition parameters and processes. When one or more of the implementation steps or the implementation condition parameters go beyond the protection scope claimed by the present disclosure, the performance of the product is much lower than that of the present disclosure.