High-strength molybdenum nickel boron ternary boride material and manufacturing preparation method thereof

[0022] Embodiment 1: This embodiment provides a high-strength molybdenum nickel boron ternary boride material, and its element content percentage is: boron (B) content is 3%, molybdenum (Mo) content is 40%; chromium (Cr) content is 8%, carbon (C) content is 0.2%, vanadium (V) content is 3%, niobium (Nb) content is 4%, tungsten (W) content is 0.5%, cerium The content of (Ce) is 0.3%, the content of manganese (Mn) is 3%, and the content of nickel (Ni) is 38%. Mo 2 NiB 2 The basic component of the base cermet is the hard phase Mo 2 NiB 2 With binder phase Ni, Mo 2 NiB 2 The crystal structure is orthorhombic crystal system, which is transformed into tetragonal crystal system after adding appropriate amount of Cr and V. During the liquid phase sintering process, the crystal grains grow unevenly and produce sharp angles, which causes the hard phase crystal grains to adhere to the metal. The bonding of the phase is poor, which is not conducive to the improvement of the strength and toughness of the cermet. In order to improve its comprehensive performance, W, Cr, and other elements are added in an appropriate amount. W and Cr elements exist in both the hard phase and the binder phase, and can improve Mo in the hard phase 2 NiB 2 The structure and performance of the base metal ceramics; in the binder phase, it is beneficial to improve the corrosion resistance of the alloy. Add appropriate amount of Ce, V, Cr 3 C 2 , Nb can significantly inhibit the growth of crystal grains. To reduce Mo 2 NiB 2 The oxygen content in the base cermet is reduced by adding an appropriate amount of C element, and CO is generated and discharged during the sintering process.

[0023] A preparation method for producing the above-mentioned high-strength molybdenum nickel boron ternary boride material, which comprises the following steps:

[0024] (1) Ingredients: the elements and their mass percentages are as follows: the content of boron (B) is 3%, the content of molybdenum (Mo) is 40%; the content of chromium (Cr) is 8%, and the content of carbon (C) is 0.2%, the content of vanadium (V) is 3%, the content of niobium (Nb) is 4%, the content of tungsten (W) is 0.5%, the content of cerium (Ce) is 0.3%, and the content of manganese (Mn) is 3%, the content of nickel (Ni) is 38%;

[0025] (2) Melting: Put the above ingredients into vacuum smelting, the smelting time is at least 1.5h, and the smelting temperature is 1800~2000℃. Mo is formed during the smelting process. 2 NiB 2 The hard phase is homogenized by magnetic stirring;

[0026] (3) Atomization: Then enter the gas atomization, and the gas atomization pressure is 2.5-10Mpa. During the atomization process, under the impact of the high-speed and high-pressure airflow, a coated Mo is formed 2 NiB 2 Base ternary boride cermet powder;

[0027] Or then enter the water atomization operation, the water atomization pressure is 18-25Mpa, and the coating type Mo is formed under the impact of the high-speed and high-pressure liquid flow during the atomization process. 2 NiB 2 Base ternary boride cermet powder;

[0028] Compared with water atomization, gas atomization has a slightly slower cooling rate, and the solidification time of metal droplets during the falling process is slightly longer, and the shrinkage is more sufficient. Therefore, gas atomization powder has better appearance and sphericity than water atomization powder, so it flows Sex is more;

[0029] (4) Analysis: For the above Mo 2 NiB 2 The basic ternary boride cermet powder is sieved and particle size analysis; during the atomization process, the fluctuation of gas (liquid) pressure will directly affect the particle size and shape of the powder, and the thickness of the crystal grain. Due to the fast cooling rate, the growth of crystal grains is inhibited, which is beneficial to improve the hardness and strength of the alloy during subsequent molding. The cooling speed of the gas atomization process is relatively slow, but the powder is more regular, the sphericity is better, and the powder fluidity is higher. Due to the atmosphere protection, its oxygen content is as low as 0.023%; the water atomization process has a relatively fast cooling rate. The uniformity of the particles is worse than that of aerosolization, and there are irregular dumbbell-shaped particles. These irregular particles make the fluidity of the powder worse, and the oxygen content is about 0.13%. The particle size analysis is performed by the BT-9300ST laser particle size analyzer; see the following table, the particle size distribution of the atomized powder is listed.

[0030]

[0031] It can be seen that -500 goals accounted for 18.93%, +500/-270 goals accounted for 23.53%, +270/-80 goals accounted for 55.02%, and +80 goals accounted for 3.52%. Mo 2 NiB 2 The distribution range of aerosolized powder is mainly concentrated in +270/-80 mesh, and its average particle size is 64.47μm;

[0032] (5) Hot isostatic pressing sintering: HIP hot isostatic pressing sintering produces highly dense and high-strength Mo 2 NiB 2 Base cermet materials. Specifically, the step (5) specifically includes the following steps:

[0033] (5.1) Making the sheath: Hot isostatic pressing requires high air tightness, and strict testing must be implemented before high temperature and high pressure. The structure of the sheath is designed according to the specifications of the required materials, and the sheath can be used after being cleaned, welded and leak-tested;

[0034] (5.2) Packing and tapping: the qualified package is packed and compacted, the powder is put into the package from the evacuation tube, and placed on the vibrating table to vibrate to make the powder compact; the powder must be installed in the lower part of the evacuation tube To ensure fullness;

[0035] (5.3) Vacuuming of the sheath: vacuuming the sheath filled with powder, the vacuum pressure must reach 10 -4 Pa, then after the evacuated tube is burned red, clamp the evacuated tube immediately to seal it;

[0036] (5.4) Hot isostatic pressing sintering: set the package into a furnace, and heat it at a rate of 3-12°C/min until the sintering temperature reaches 1200-1450°C, the sintering pressure is 80-200MPa, and the holding time is 30-60min. cool down;

[0037] (5.5) Post-treatment: After the furnace is released, stress-relieving annealing treatment is carried out, and after removing the sheath, the Mo with high density and high strength is obtained 2 NiB 2 Base cermet.

[0038] (6) Strength test: Mo obtained by the present invention 2 NiB 2 The base metal ceramic material has a bending strength of 3600 MPa.

[0039] Embodiment 2: This embodiment provides a high-strength molybdenum-nickel-boron ternary boride material and its preparation method, which are basically the same as Embodiment 1, except that the elements and their mass percentages are as follows: Boron (B) The content of is 5%, the content of molybdenum (Mo) is 55%; the content of chromium (Cr) is 1%, the content of carbon (C) is 0.5%, the content of vanadium (V) is 4%, and the content of niobium (Nb) The content of tungsten (W) is 4%, the content of cerium (Ce) is 1%, the content of manganese (Mn) is 1%, and the content of nickel (Ni) is 27.5%.

[0040] Embodiment 3: This embodiment provides a high-strength molybdenum-nickel-boron ternary boride material and its preparation method, which are basically the same as Embodiment 1, except that the elements and their mass percentages are as follows: Boron (B) The content is 6%, the content of molybdenum (Mo) is 35%; the content of chromium (Cr) is 6%, the content of carbon (C) is 0.8%, the content of vanadium (V) is 0.5%, and the content of niobium (Nb) The content of tungsten (W) is 5%, the content of cerium (Ce) is 0.1%, the content of manganese (Mn) is 2%, and the content of nickel (Ni) is 41.6%.