Al3BC3-based crucible for nickel-based superalloy smelting and preparation method of Al3BC3-based crucible

Abstract

The invention relates to an Al3BC3-based crucible for nickel-based high-temperature alloy smelting and a preparation method of the Al3BC3-based crucible. According to the technical scheme, yttrium oxide powder and titanium boride powder are mixed to obtain a mixed reinforced phase; adding the mixed reinforcing phase into the aluminum carboboride powder to obtain mixed powder; putting mixed powder, absolute ethyl alcohol and the ball-milled beads into a ball mill, and carrying out ball milling to obtain mixed slurry; drying and grinding the mixed slurry to obtain a ground material; grinding materials are placed in a mold pasted with graphite paper, and the grinding materials are compacted and sealed at an upper end opening through a graphite plunger; putting the sealed mold into a hot-pressing sintering furnace, heating and pressurizing at the same time under vacuum and pressurizing conditions, and keeping the temperature and the pressure; the Al3BC3 composite material for the nickel-based high-temperature alloy smelting crucible is obtained; and machining is conducted, and the Al3BC3-based crucible for nickel-based high-temperature alloy smelting is obtained. The prepared product is good in thermal shock resistance, excellent in mechanical property, good in nickel-based high-temperature alloy melt erosion resistance and excellent in penetration resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of Al3BC3-based crucibles for melting superalloys at high temperatures. Specifically, it relates to an Al3BC3-based crucible for melting nickel-based superalloys and a preparation method thereof. Background Art

[0002] Nickel-based superalloys have excellent comprehensive properties, such as low density, high strength, good corrosion resistance and high-temperature stability, and are widely used in the fields of aerospace, construction and medical treatment, etc. As an essential melting container for superalloys at high temperatures, the performance of the crucible is a key factor affecting the melting quality of superalloys.

[0003] During the high-temperature melting process, in order to prevent the crucible material from reacting with the superalloy and improve the purity of the superalloy, the crucible material for melting superalloys at high temperatures should have excellent erosion resistance; at the same time, the crucible material for melting superalloys at high temperatures should also have good mechanical properties. Al3BC3 is one of the most stable compounds in the Al–B–C system, with a low density (~2.66 g·cm -3) It has the characteristics of high melting point (~2100 °C), high flexural strength (~185 MPa), high Young's modulus (~163 GPa), high Vickers hardness (~11.1 GPa), and excellent chemical stability (Lee S H, Kim H D, Choi S C, et al. Chemical composition and microstructure of Al3BC3 prepared by different densification methods[J]. Journal of the European Ceramic Society, 2010, 30(4):1015 - 1020.), and is used as an antioxidant for magnesia - carbon refractories (Wang X, Deng C J, Di J H, et al. Enhanced oxidation resistance of low - carbon MgO–C refractories with Al3BC3–Al antioxidants: A synergistic effect[J]. Journal of the American Ceramic Society, 2023, 106(6):3749 - 3764.) and a toughening and strengthening phase for ceramic materials (Yan H, Deng C J, Xing G C, et al. Enhanced mechanical properties of SPS sintered h–BN based ceramics with Al3BC3 addition[J]. Journal of Alloys and Compounds, 2024, 1007:176447.), but there is no report on its use as a raw material for preparing crucibles.

[0004] The patented technology of "An isostatic pressing formed corundum - spinel crucible and its preparation method (CN201210440801.0)" uses corundum - spinel as the raw material. Although the prepared corundum - spinel crucible has a relatively high bulk density, low porosity, and good thermal shock stability, its high - temperature mechanical properties are low.

[0005] The patented technology of "An aluminum - magnesium - based ceramic crucible for melting superalloys and its preparation method (CN202311773401.6)" uses corundum - spinel, magnesia - alumina spinel, and α - alumina as raw materials. The prepared crucible material has stable chemical properties and will not react with superalloys during use, nor will it precipitate harmful substances. However, its excessive densification results in insufficient thermal shock stability of the crucible material.

[0006] The patented technology "A method for preparing an alumina-based crucible for high-temperature alloy smelting (CN202411580995.3)" uses alumina as raw material. Although the prepared crucible material has good mechanical properties and high thermal shock resistance, its high porosity affects its corrosion resistance. Summary of the invention

[0007] The present invention aims to overcome the defects of the prior art and has the object of providing a method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys with Al3BC3 as the main raw material. The Al3BC3-based crucible for smelting nickel-based high-temperature alloys prepared by the method has good thermal shock stability, excellent mechanical properties, good resistance to erosion by nickel-based high-temperature alloy melts and excellent resistance to penetration by nickel-based high-temperature alloy melts.

[0008] To achieve the above purpose, the technical solution steps adopted by the present invention are:

[0009] Step 1: Mix the yttrium oxide powder and the titanium boride powder in a mass ratio of 1:0.1-9.0 to obtain a mixed reinforcement phase.

[0010] Step 2: Using 85-98 wt% of aluminum boron carbide powder and 2-15 wt% of the mixed reinforcing phase as raw materials, adding the mixed reinforcing phase into the aluminum boron carbide powder to obtain a mixed powder.

[0011] Step 3: prepare the mixed powder: anhydrous ethanol: ball milling beads in a mass ratio of 1:6-8:3-6, place the mixed powder, anhydrous ethanol and the ball milling beads in a ball mill, and ball mill to obtain a mixed slurry.

[0012] Step 4: Dry the mixed slurry to obtain a mixed powder; then grind the mixed powder to a particle size less than 25 μm to obtain a grind.

[0013] Step 5: First, a graphite paper is tightly attached to the inner surface of a cylindrical mold, and the nominal inner diameter of the mold is equal to the outer diameter of the Al3BC3-based crucible for smelting the nickel-based high-temperature alloy to be produced; then, the abrasive is placed in the mold with the graphite paper attached, and then the abrasive is compacted and sealed at the upper port with a graphite plunger.

[0014] Step 6: Place the sealed mold into a hot pressing sintering furnace, evacuate to below 0.20 Pa, pressurize to 30-60 MPa, and then simultaneously increase the temperature to 1600-1900° C. and increase the pressure to 40-70 MPa, and keep the temperature and pressure for 45-75 minutes.

[0015] Step 7: Cool down naturally and unload to normal pressure, take out the mold, and obtain the Al3BC3 composite material for nickel-based high-temperature alloy melting crucible; mechanical processing, to obtain the Al3BC3-based crucible for nickel-based high-temperature alloy melting.

[0016] The Y2O3 content of the yttrium oxide powder is ≥ 99.5 wt%; the particle size of the yttrium oxide powder is less than 6 μm.

[0017] The TiB2 content of the titanium boride powder is ≥ 99.5 wt%; the particle size of the titanium boride powder is less than 4 μm.

[0018] The Al3BC3 content of the aluminum borocarbide powder is ≥ 99.9 wt%; the particle size of the aluminum borocarbide powder is less than 15 μm.

[0019] The material of the ball milling beads is agate or zirconia.

[0020] The rotation speed of the ball milling is 150 - 300 r / min, and the ball milling time is 8 - 16 h.

[0021] The drying temperature is 60 - 100 °C, and the drying time is 24 - 48 h.

[0022] The heating rate is 10 - 40 °C / min.

[0023] The pressure increasing rate is 0.25 - 1.47 MPa / min.

[0024] Due to the adoption of the above technical solution, the present invention has the following positive effects compared with the prior art:

[0025] The present invention uses aluminum borocarbide powder, yttrium oxide powder and titanium boride powder as raw materials. For the Al3BC3-based crucible for nickel-based superalloy melting prepared hereinafter (Al3BC3-based crucible), yttrium aluminum garnet particles are in-situ generated between Al3BC3 particles. While optimizing the pore structure, size and distribution in the Al3BC3-based crucible material, it avoids the adverse effects of the volume effects generated by different particles on the thermal shock stability of the crucible, and solves the problem of poor thermal shock stability of the existing crucibles. Therefore, the prepared Al3BC3-based crucible has good thermal shock stability.

[0026] The present invention in-situ forms uniformly distributed yttrium aluminum garnet fine crystals, and uses this as the binding phase between particles in the Al3BC3-based crucible, improving the binding strength between particles. TiB2 is uniformly distributed in the Al3BC3 particles, increasing the grain boundaries of Al3BC3 and inhibiting the propagation of microcracks inside the Al3BC3-based crucible material caused by external stress under high temperature conditions. Therefore, the prepared Al3BC3-based crucible has excellent mechanical properties.

[0027] The Al3BC3 powder used in the present invention has excellent erosion resistance and is difficult to be wetted by the nickel-based superalloy melt. At the same time, the strengthening of the inter-particle bonding and pore filling by yttrium aluminum garnet and titanium boride in the Al3BC3-based crucible can effectively reduce the penetration and reaction of the nickel-based superalloy melt. Therefore, the prepared Al3BC3-based crucible has excellent erosion resistance and penetration resistance to the nickel-based superalloy melt.

[0028] The Al3BC3-based crucible prepared in the present invention was detected: the relative density is 88.5 - 95.4%; the room temperature flexural strength is 172 - 356 MPa; the fracture toughness is 4.5 - 8.2 MPa·m 1 / 2 ; the Vickers hardness is 10.9 - 16.6 GPa; the high temperature flexural strength is 92 - 248 MPa (1400 °C, carbon buried); the thermal shock stability is 12 - 16 times (1100 °C, water cooling); no obvious erosion and penetration were found in the experiment of the nickel-based superalloy melt.

[0029] The detection standards for the performance indicators involved in the present invention: the bulk density is measured according to GB / T 2999-2016; the room temperature flexural strength is measured according to GB / T 3001-2017; the fracture toughness is measured according to GB / T 19748-2019; the Vickers hardness is measured according to GB / T 4340.1-2009; the high temperature flexural strength is measured according to GB / T 3002-2017; the thermal shock stability is measured according to GB / T 30873-2014.

[0030] Therefore, the Al3BC3-based crucible for melting nickel-based superalloys prepared in the present invention has the characteristics of good thermal shock stability, excellent mechanical properties, good erosion resistance to the nickel-based superalloy melt, and excellent penetration resistance to the nickel-based superalloy melt. Specific embodiments

[0031] The following further describes the present invention in conjunction with specific embodiments, which is not a limitation to its protection scope.

[0032] An Al3BC3-based crucible for melting nickel-based superalloys and a preparation method thereof. The steps of the preparation method described in this specific embodiment are as follows:

[0033] Step 1: Weigh the yttrium oxide powder and titanium boride powder according to the mass ratio of yttrium oxide powder: titanium boride powder of 1:0.1 - 9.0, and mix the yttrium oxide powder and the titanium boride powder to obtain a mixed reinforcing phase.

[0034] Step 2: Using 85 - 98 wt% of aluminum carbide boron powder and 2 - 15 wt% of the mixed reinforcing phase as raw materials, add the mixed reinforcing phase to the aluminum carbide boron powder to obtain a mixed powder.

[0035] Step 3: prepare the mixed powder: anhydrous ethanol: ball milling beads in a mass ratio of 1:6-8:3-6, place the mixed powder, anhydrous ethanol and the ball milling beads in a ball mill, and ball mill to obtain a mixed slurry.

[0036] Step 4: Dry the mixed slurry to obtain a mixed powder; then grind the mixed powder to a particle size less than 25 μm to obtain a grind.

[0037] Step 5: First, a graphite paper is tightly attached to the inner surface of the cylindrical mold, and then the abrasive is placed in the mold with the graphite paper attached, and then the abrasive is compacted and sealed at the upper port with a graphite plunger.

[0038] Step 6: Place the sealed mold into a hot pressing sintering furnace, evacuate to below 0.20 Pa, pressurize to 30-60 MPa, and then simultaneously increase the temperature to 1600-1900° C. and increase the pressure to 40-70 MPa, and keep the temperature and pressure for 45-75 minutes.

[0039] Step 7: Cool down naturally and unload to normal pressure, take out the mold, and obtain the Al3BC3 composite material for nickel-based high-temperature alloy melting crucible; mechanical processing, to obtain the Al3BC3-based crucible for nickel-based high-temperature alloy melting.

[0040] The ball milling beads are made of agate or zirconium oxide.

[0041] The rotation speed of the ball mill is 150-300 r / min, and the ball milling time is 8-16 hours.

[0042] The drying temperature is 60-100° C., and the drying time is 24-48 hours.

[0043] The heating rate is 10-40°C / min.

[0044] The rate of the pressurization is 0.25-1.47 MPa / min.

[0045] In this specific implementation mode;

[0046] The Y2O3 content of the yttrium oxide powder is ≥99.5wt%; and the particle size of the yttrium oxide powder is less than 6μm.

[0047] The TiB2 content of the titanium boride powder is ≥99.5wt%; and the particle size of the titanium boride powder is less than 4μm.

[0048] The Al3BC3 content of the aluminum carbide powder is ≥99.9wt%; and the particle size of the aluminum carbide powder is less than 15μm.

[0049] The nominal inner diameter of the mold is equal to the outer diameter of the Al3BC3-based crucible used for smelting the nickel-based high-temperature alloy to be produced.

[0050] This will not be described in detail in the embodiments.

[0051] Example 1

[0052] An Al3BC3-based crucible for smelting nickel-based high-temperature alloys and a preparation method thereof. The steps of the preparation method described in this embodiment are:

[0053] Step 1: Mix the yttrium oxide powder and the titanium boride powder in a mass ratio of 1:9.0 to obtain a mixed reinforcement phase.

[0054] Step 2: Using 85 wt% of aluminum boron carbide powder and 15 wt% of the mixed reinforcing phase as raw materials, adding the mixed reinforcing phase into the aluminum boron carbide powder to obtain a mixed powder.

[0055] Step 3: prepare the mixed powder, anhydrous ethanol and ball milling beads in a ball mill according to the mass ratio of the mixed powder, anhydrous ethanol and ball milling beads of 1:8:6, and obtain a mixed slurry by ball milling.

[0056] Step 4: Dry the mixed slurry to obtain a mixed powder; then grind the mixed powder to a particle size less than 25 μm to obtain a grind.

[0057] Step 5: First, a graphite paper is tightly attached to the inner surface of the cylindrical mold, and then the abrasive is placed in the mold with the graphite paper attached, and then the abrasive is compacted and sealed at the upper port with a graphite plunger.

[0058] Step 6: Place the sealed mold into a hot pressing sintering furnace, evacuate to 0.20 Pa, pressurize to 30 MPa, then simultaneously increase the temperature to 1600°C and the pressure to 40 MPa, and keep the temperature and pressure for 45 minutes.

[0059] Step 7: Cool down naturally and unload to normal pressure, take out the mold, and obtain the Al3BC3 composite material for nickel-based high-temperature alloy melting crucible; mechanical processing, to obtain the Al3BC3-based crucible for nickel-based high-temperature alloy melting.

[0060] The ball milling beads are made of agate.

[0061] The rotation speed of the ball mill is 150 r / min, and the ball milling time is 8 h.

[0062] The drying temperature is 60° C. and the drying time is 48 hours.

[0063] The heating rate is 10°C / min.

[0064] The rate of pressurization is 0.25 MPa / min.

[0065] The Al3BC3-based crucible for smelting nickel-based high-temperature alloy prepared by the present invention is tested to have a relative density of 88.5%, a room temperature flexural strength of 172 MPa, and a fracture toughness of 4.5 MPa·m 1 / 2 ; Vickers hardness is 10.9GPa; high temperature flexural strength is 92MPa (1400℃, carbon buried); thermal shock stability is 13 times (1100℃, water cooling); no obvious erosion and penetration were found in the test of resistance to molten nickel-based high-temperature alloy.

[0066] Example 2

[0067] An Al3BC3-based crucible for smelting nickel-based high-temperature alloys and a preparation method thereof. The steps of the preparation method described in this embodiment are:

[0068] Step 1: Mix the yttrium oxide powder and the titanium boride powder in a mass ratio of 1:7.0 to obtain a mixed reinforcement phase.

[0069] Step 2: Using 88 wt% of aluminum boron carbide powder and 12 wt% of the mixed reinforcing phase as raw materials, adding the mixed reinforcing phase into the aluminum boron carbide powder to obtain a mixed powder.

[0070] Step 3: prepare the mixed powder, anhydrous ethanol and ball milling beads in a ball mill according to a mass ratio of 1:7:5, place the mixed powder, anhydrous ethanol and ball milling beads in a ball mill, and ball mill to obtain a mixed slurry.

[0071] Step 4: Dry the mixed slurry to obtain a mixed powder; then grind the mixed powder to a particle size less than 25 μm to obtain a grind.

[0072] Step 5: First, a graphite paper is tightly attached to the inner surface of the cylindrical mold, and then the abrasive is placed in the mold with the graphite paper attached, and then the abrasive is compacted and sealed at the upper port with a graphite plunger.

[0073] Step 6: Place the sealed mold into a hot pressing sintering furnace, evacuate to 0.18 Pa, pressurize to 35 MPa, then simultaneously increase the temperature to 1650°C and the pressure to 45 MPa, and keep the temperature and pressure for 50 minutes.

[0074] Step 7: Cool down naturally and unload to normal pressure, take out the mold, and obtain the Al3BC3 composite material for nickel-based high-temperature alloy melting crucible; mechanical processing, to obtain the Al3BC3-based crucible for nickel-based high-temperature alloy melting.

[0075] The ball milling beads are made of zirconium oxide.

[0076] The rotation speed of the ball mill is 180 r / min, and the ball milling time is 10 h.

[0077] The drying temperature is 70° C. and the drying time is 45 h.

[0078] The heating rate is 15°C / min.

[0079] The rate of pressurization is 0.41 MPa / min.

[0080] The Al3BC3-based crucible for smelting nickel-based high-temperature alloy prepared by the present invention is tested to have a relative density of 92.5%, a room temperature flexural strength of 226 MPa, and a fracture toughness of 5.1 MPa·m 1 / 2 ; Vickers hardness is 11.6GPa; high temperature flexural strength is 109MPa (1400℃, carbon buried); thermal shock stability is 14 times (1100℃, water cooling); no obvious erosion and penetration were found in the test of resistance to molten nickel-based high-temperature alloy.

[0081] Example 3

[0082] An Al3BC3-based crucible for smelting nickel-based high-temperature alloys and a preparation method thereof. The steps of the preparation method described in this embodiment are:

[0083] Step 1: Mix the yttrium oxide powder and the titanium boride powder in a mass ratio of 1:5.0 to obtain a mixed reinforcement phase.

[0084] Step 2: Using 91 wt% of aluminum boron carbide powder and 9 wt% of the mixed reinforcing phase as raw materials, adding the mixed reinforcing phase into the aluminum boron carbide powder to obtain a mixed powder.

[0085] Step 3: prepare the mixed powder, anhydrous ethanol and ball milling beads in a ball mill according to the mass ratio of the mixed powder, anhydrous ethanol and ball milling beads of 1:6:4, and obtain a mixed slurry by ball milling.

[0086] Step 4: Dry the mixed slurry to obtain a mixed powder; then grind the mixed powder to a particle size less than 25 μm to obtain a grind.

[0087] Step 5: First, a graphite paper is tightly attached to the inner surface of the cylindrical mold, and then the abrasive is placed in the mold with the graphite paper attached, and then the abrasive is compacted and sealed at the upper port with a graphite plunger.

[0088] Step 6: Place the sealed mold into a hot pressing sintering furnace, evacuate to 0.15 Pa, pressurize to 40 MPa, then simultaneously increase the temperature to 1700°C and the pressure to 50 MPa, and keep the temperature and pressure for 55 minutes.

[0089] Step 7: Naturally cool down and unload to atmospheric pressure, take out the mold to obtain the Al3BC3 composite material for nickel-based superalloy melting crucibles; perform machining to produce an Al3BC3-based crucible for nickel-based superalloy melting.

[0090] The material of the ball milling beads is agate.

[0091] The rotation speed of the ball milling is 200 r / min, and the ball milling time is 12 h.

[0092] The drying temperature is 80 °C, and the drying time is 40 h.

[0093] The heating rate is 20 °C / min.

[0094] The pressure increasing rate is 0.59 MPa / min.

[0095] The Al3BC3-based crucible for nickel-based superalloy melting prepared by the present invention is detected: the relative density is 94.1%; the room temperature flexural strength is 335 MPa; the fracture toughness is 8.2 MPa·m 1 / 2 ; the Vickers hardness is 13.4 GPa; the high temperature flexural strength is 189 MPa (1400 °C, carbon buried); the thermal shock stability is 16 times (1100 °C, water cooling); no obvious erosion and penetration are seen in the experiment of resisting molten nickel-based superalloy.

[0096] Example 4

[0097] An Al3BC3-based crucible for nickel-based superalloy melting and a preparation method thereof. The steps of the preparation method described in this example are:

[0098] Step 1: Weigh the yttrium oxide powder and titanium boride powder according to the mass ratio of 1:3.0, mix the yttrium oxide powder and the titanium boride powder to obtain a mixed reinforcing phase.

[0099] Step 2: Use 93 wt% of aluminum carbide boride powder and 7 wt% of the mixed reinforcing phase as raw materials, add the mixed reinforcing phase to the aluminum carbide boride powder to obtain a mixed powder.

[0100] Step 3: Weigh the mixed powder, absolute ethanol, and ball milling beads according to the mass ratio of 1:7:6, place the mixed powder, absolute ethanol, and the ball milling beads in a ball mill, and perform ball milling to obtain a mixed slurry.

[0101] Step 4: Dry the mixed slurry to obtain a mixed powder; then grind the mixed powder to a particle size less than 25 μm to obtain a grinding material.

[0102] Step 5: First, attach a graphite paper to the inner surface of the cylindrical mold, then place the abrasive in the mold with the graphite paper attached, and then compact and seal the abrasive with a graphite plunger at the upper port.

[0103] Step 6: Place the sealed mold in a hot press sintering furnace, evacuate to 0.12 Pa, apply a pressure of 60 MPa, then simultaneously raise the temperature to 1750 °C and increase the pressure to 60 MPa, and hold the temperature and pressure for 60 min.

[0104] Step 7: Naturally cool down and unload to atmospheric pressure, take out the mold to obtain the Al3BC3 composite material for nickel-based superalloy melting crucibles; perform machining to obtain the Al3BC3-based crucible for nickel-based superalloy melting.

[0105] The material of the ball milling beads is zirconia.

[0106] The rotation speed of the ball milling is 230 r / min, and the ball milling time is 13 h.

[0107] The drying temperature is 90 °C, and the drying time is 35 h.

[0108] The heating rate is 25 °C / min.

[0109] The pressure increasing rate is 0.86 MPa / min.

[0110] The Al3BC3-based crucible for nickel-based superalloy melting prepared by the present invention is detected: the relative density is 95.4%; the room temperature flexural strength is 356 MPa; the fracture toughness is 7.5 MPa·m 1 / 2 ; the Vickers hardness is 16.6 GPa; the high temperature flexural strength is 248 MPa (1400 °C, carbon buried); the thermal shock stability is 16 times (1100 °C, water cooling); no obvious erosion and penetration are observed in the experiment of resisting molten nickel-based superalloy.

[0111] Example 5

[0112] An Al3BC3-based crucible for nickel-based superalloy melting and a preparation method thereof. The steps of the preparation method in this example are as follows:

[0113] Step 1: Weigh the yttrium oxide powder and titanium boride powder according to the mass ratio of 1:1.0, mix the yttrium oxide powder and the titanium boride powder to obtain a mixed reinforcing phase.

[0114] Step 2: Use 95 wt% of aluminum carbide boride powder and 5 wt% of the mixed reinforcing phase as raw materials, add the mixed reinforcing phase to the aluminum carbide boride powder to obtain a mixed powder.

[0115] Step 3: According to the mass ratio of the mixed powder: anhydrous ethanol: ball milling beads of 1:8:3, the mixed powder, anhydrous ethanol and the ball milling beads are placed in a ball mill, and ball milled to obtain a mixed slurry.

[0116] Step 4: Dry the mixed slurry to obtain a mixed powder; then grind the mixed powder to a particle size less than 25 μm to obtain a grind.

[0117] Step 5: First, a graphite paper is tightly attached to the inner surface of the cylindrical mold, and then the abrasive is placed in the mold with the graphite paper attached, and then the abrasive is compacted and sealed at the upper port with a graphite plunger.

[0118] Step 6: Place the sealed mold into a hot pressing sintering furnace, evacuate to 0.10 Pa, pressurize to 45 MPa, then simultaneously increase the temperature to 1800°C and the pressure to 65 MPa, and keep the temperature and pressure for 70 minutes.

[0119] Step 7: Cool down naturally and unload to normal pressure, take out the mold, and obtain the Al3BC3 composite material for nickel-based high-temperature alloy melting crucible; mechanical processing, to obtain the Al3BC3-based crucible for nickel-based high-temperature alloy melting.

[0120] The ball milling beads are made of agate.

[0121] The rotation speed of the ball mill is 270 r / min, and the ball milling time is 15 h.

[0122] The drying temperature is 100° C. and the drying time is 24 hours.

[0123] The heating rate is 30°C / min.

[0124] The rate of pressurization is 1.08 MPa / min.

[0125] The Al3BC3-based crucible for smelting nickel-based high-temperature alloy prepared by the present invention is tested to have a relative density of 93.5%, a room temperature flexural strength of 242 MPa, and a fracture toughness of 6.5 MPa·m 1 / 2 ; Vickers hardness is 13.6GPa; high temperature flexural strength is 159MPa (1400℃, carbon buried); thermal shock stability is 12 times (1100℃, water cooling); no obvious erosion and penetration were found in the test of resistance to molten nickel-based high-temperature alloy.

[0126] Example 6

[0127] An Al3BC3-based crucible for smelting nickel-based high-temperature alloys and a preparation method thereof. The steps of the preparation method described in this embodiment are:

[0128] Step 1: Mix the yttrium oxide powder and the titanium boride powder in a mass ratio of 1:0.1 to obtain a mixed reinforcement phase.

[0129] Step 2: Using 98 wt % of aluminum boron carbide powder and 2 wt % of the mixed reinforcing phase as raw materials, adding the mixed reinforcing phase into the aluminum boron carbide powder to obtain a mixed powder.

[0130] Step 3: prepare the mixed powder, anhydrous ethanol and ball milling beads in a ball mill according to the mass ratio of the mixed powder, anhydrous ethanol and ball milling beads of 1:6:5, and ball mill the mixed powder, anhydrous ethanol and ball milling beads to obtain a mixed slurry.

[0131] Step 4: Dry the mixed slurry to obtain a mixed powder; then grind the mixed powder to a particle size less than 25 μm to obtain a grind.

[0132] Step 5: First, a graphite paper is tightly attached to the inner surface of the cylindrical mold, and then the abrasive is placed in the mold with the graphite paper attached, and then the abrasive is compacted and sealed at the upper port with a graphite plunger.

[0133] Step 6: Place the sealed mold into a hot pressing sintering furnace, evacuate to 0.13 Pa, pressurize to 50 MPa, then simultaneously increase the temperature to 1900°C and the pressure to 70 MPa, and keep the temperature and pressure for 75 minutes.

[0134] Step 7: Cool down naturally and unload to normal pressure, take out the mold, and obtain the Al3BC3 composite material for nickel-based high-temperature alloy melting crucible; mechanical processing, to obtain the Al3BC3-based crucible for nickel-based high-temperature alloy melting.

[0135] The ball milling beads are made of zirconium oxide.

[0136] The rotation speed of the ball mill is 300 r / min, and the ball milling time is 16 h.

[0137] The drying temperature is 85° C. and the drying time is 30 h.

[0138] The heating rate is 40°C / min.

[0139] The rate of pressurization is 1.47 MPa / min.

[0140] The Al3BC3-based crucible for smelting nickel-based high-temperature alloy prepared by the present invention is tested to have a relative density of 90.1%, a room temperature flexural strength of 209 MPa, and a fracture toughness of 5.6 MPa·m 1 / 2; The Vickers hardness is 12.5 GPa; the high-temperature flexural strength is 99 MPa (at 1400 °C, carbon buried); the thermal shock stability is 13 times (at 1100 °C, water-cooled); no obvious erosion and penetration were observed in the experiment of resisting molten nickel-based superalloy.

[0141] The following are the positive effects of this specific embodiment compared with the prior art:

[0142] This specific embodiment uses aluminum carbide boron powder, yttrium oxide powder and titanium boride powder as raw materials. The Al3BC3-based crucible for melting nickel-based superalloys prepared hereinafter (referred to as Al3BC3-based crucible) in-situ generates yttrium aluminum garnet particles between Al3BC3 particles. While optimizing the pore structure, size and distribution in the Al3BC3-based crucible material, it avoids the adverse effects of the volume effects generated by different particles on the thermal shock stability of the crucible, and solves the problem of poor thermal shock stability of the existing crucibles. Therefore, the prepared Al3BC3-based crucible has good thermal shock stability.

[0143] This specific embodiment forms uniformly distributed fine yttrium aluminum garnet crystals in-situ and uses them as the bonding phase between particles in the Al3BC3-based crucible, improving the bonding strength between particles. TiB2 is uniformly distributed in the Al3BC3 particles, increasing the grain boundaries of Al3BC3 and suppressing the propagation of internal microcracks in the Al3BC3-based crucible material caused by external stress under high-temperature conditions. Therefore, the prepared Al3BC3-based crucible has excellent mechanical properties.

[0144] The Al3BC3 powder used in this specific embodiment has excellent erosion resistance and is difficult to be wetted by the nickel-based superalloy melt. At the same time, the strengthening of the bonding between particles and pore filling by yttrium aluminum garnet and titanium boride in the Al3BC3-based crucible can effectively reduce the penetration and reaction of the nickel-based superalloy melt. Therefore, the prepared Al3BC3-based crucible has excellent erosion resistance and penetration resistance to the nickel-based superalloy melt.

[0145] The Al3BC3-based crucible prepared in this specific embodiment was detected: the relative density is 88.5 - 95.4%; the room-temperature flexural strength is 172 - 356 MPa; the fracture toughness is 4.5 - 8.2 MPa·m 1 / 2 ; The Vickers hardness is 10.9 - 16.6 GPa; the high-temperature flexural strength is 92 - 248 MPa (at 1400 °C, carbon buried); the thermal shock stability is 12 - 16 times (at 1100 °C, water-cooled); no obvious erosion and penetration were observed in the experiment of resisting the nickel-based superalloy melt.

[0146] Detection standards for the performance indicators involved in this specific implementation method: The bulk density is measured in accordance with GB / T 2999-2016; the cold flexural strength is measured in accordance with GB / T 3001-2017; the fracture toughness is measured in accordance with GB / T 19748-2019; the Vickers hardness is measured in accordance with GB / T 4340.1-2009; the hot flexural strength is measured in accordance with GB / T 3002-2017; the thermal shock stability is measured in accordance with GB / T 30873-2014.

[0147] Therefore, the Al3BC3-based crucible for nickel-based superalloy melting prepared by this specific implementation method has the characteristics of good thermal shock stability, excellent mechanical properties, good resistance to nickel-based superalloy melt erosion, and excellent resistance to nickel-based superalloy melt penetration.

Claims

1. A method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys, characterized in that: The steps of the preparation method are: Step 1, mixing the yttrium oxide powder and the titanium boride powder in a mass ratio of 1:0.1-9.0 to obtain a mixed reinforcement phase; Step 2: using 85-98 wt% of aluminum boron carbide powder and 2-15 wt% of the mixed reinforcing phase as raw materials, adding the mixed reinforcing phase into the aluminum boron carbide powder to obtain a mixed powder; Step 3, according to the mass ratio of the mixed powder: anhydrous ethanol: ball milling beads of 1: 6-8: 3-6, the mixed powder, anhydrous ethanol and the ball milling beads are placed in a ball mill, and ball milled to obtain a mixed slurry; Step 4: drying the mixed slurry to obtain a mixed powder; grinding the mixed powder to a particle size of less than 25 μm to obtain a grind; Step 5: First, a graphite paper is attached to the inner surface of the cylindrical mold, and then the abrasive is placed in the mold with the graphite paper attached, and then the abrasive is compacted and sealed at the upper port with a graphite plunger; Step 6: Place the sealed mold into a hot pressing sintering furnace, evacuate to below 0.20 Pa, pressurize to 30-60 MPa, and then simultaneously increase the temperature to 1600-1900°C and the pressure to 40-70 MPa, and keep the temperature and pressure for 45-75 minutes; Step 7: Cool down naturally and unload to normal pressure, take out the mold, and obtain the Al3BC3 composite material for nickel-based high-temperature alloy melting crucible; mechanical processing, to obtain the Al3BC3-based crucible for nickel-based high-temperature alloy melting.

2. The method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to claim 1, characterized in that: The Y2O3 content of the yttrium oxide powder is ≥99.5wt%; and the particle size of the yttrium oxide powder is less than 6μm.

3. The method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to claim 1, characterized in that: The TiB2 content of the titanium boride powder is ≥99.5wt%; and the particle size of the titanium boride powder is less than 4μm.

4. The method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to claim 1, characterized in that: The Al3BC3 content of the aluminum carbide powder is ≥99.9wt%; and the particle size of the aluminum carbide powder is less than 15μm.

5. The method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to claim 1, characterized in that: The ball milling beads are made of agate or zirconium oxide.

6. The method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to claim 1, characterized in that: The rotation speed of the ball mill is 150-300 r / min, and the ball milling time is 8-16 hours.

7. The method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to claim 1, characterized in that: The drying temperature is 60-100° C., and the drying time is 24-48 hours.

8. The method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to claim 1, characterized in that: The heating rate is 10-40°C / min.

9. The method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to claim 1, characterized in that: The rate of the pressurization is 0.25-1.47 MPa / min.

10. A method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys, characterized in that The Al3BC3-based crucible for smelting nickel-based high-temperature alloys is an Al3BC3-based crucible for smelting nickel-based high-temperature alloys prepared by the method for preparing an Al3BC3-based crucible for smelting nickel-based high-temperature alloys according to any one of claims 1 to 9.