Method for in-situ preparation of Fe/TiC composite powder by vacuum carbon thermal reduction

Abstract

Provided is a method for in-situ preparation of Fe / TiC composite powder by vacuum carbon thermal reduction. Titanium dioxide, a carbonaceous reducing agent, and iron or iron oxide are used as raw materials and are mixed and uniformly stirred according to a certain mass ratio; and the mixed powder after being pressed into cakes is put into a vacuum high-temperature furnace to be heated and is subjected to thermal insulation at a temperature of 1300-1600 DEG C and a pressure of 10-200 Pa for 1-2 hours to obtain a Fe / TiC composite powder material finally. The method has the beneficial effects that (1), the titanium dioxide, the carbonaceous reducing agent, and the iron or iron oxide are used as raw materials, compared with a traditional preparation method, the cost is lower, the technologicalprocess is simple, and easy industrial production is achieved; (2), an in-situ synthesis method is adopted, titanium dioxide is reduced by carbon in iron liquid at a high temperature, and TiC is directly generated in situ, so that TiC is uniformly distributed in an iron phase and impurities between Fe / TiC interfaces are avoided; and (3), a vacuum method is used for promoting reaction to reduce the content of dissolved carbon in the iron phase, and at the same time, the deoxidation can be more thorough and the higher purity composite powder is obtained. Therefore, the method has obvious advantages in terms of cost, process and purity.

Description

technical field

[0001] The invention belongs to the field of composite materials and hard alloys, and in particular relates to a preparation method of Fe / TiC composite powder. Background technique

[0002] In recent years, ceramic-metal composites have become a current research hotspot because of their excellent wear resistance and hardness, as well as their excellent specific modulus and strength. Steel-bonded cemented carbide first appeared in the early 1960s and is an innovative ceramic-metal composite material that combines the properties of steel and carbide. Among various carbides, titanium carbide has a NaCl type cubic crystal structure, the unit cell parameter is 0.4327nm, and the space group is Fm3m. It has the characteristics of high melting point, high hardness, wear resistance and corrosion resistance, and also has good thermal conductivity. It is a promising cermet reinforcement material because of its high conductivity, electrical conductivity and chemical sta...

Examples

Embodiment 1

[0020] The present invention analyzes pure TiO 2 , graphite, electrolytic iron powder as raw materials, according to TiO 2 , C, Fe mass ratio is the ratio batching of 20:9:15, then utilizes the stirrer to mix the prepared raw material evenly, under the pressure of 230Mpa, the mixed raw material is pressed into a block with a press, and the block is placed Put it into a vacuum furnace, heat it up to 1400°C at a heating rate of 5°C / min, keep it warm for 1.5 hours, and then lower it to room temperature at a cooling rate of 5°C / min. During this period, the pressure of the vacuum furnace is kept at 10Pa. / Titanium carbide composite powder. X-ray diffraction (XRD) analysis shows that the product phase is α-Fe and TiC, and there is no other phase; electron microscope (SEM) shows that the finally obtained Fe / TiC composite powder has titanium carbide uniformly distributed in the iron phase. characteristics, and the particle size of TiC is about 2μm; nitrogen and oxygen analysis shows...

Embodiment 2

[0022] Embodiment 2 is basically the same as Embodiment 1, the difference is:

[0023] To analyze pure TiO 2 , carbon black, and electrolytic iron powder as raw materials, according to TiO 2 , C, Fe mass ratio is 20:9:5 ratio batching, then use agitator to mix the prepared raw materials evenly, with the mixed raw materials under 150Mpa pressure, press into a block with a press, put the block into a vacuum furnace, heated to 1500°C at a heating rate of 5°C / min, kept for 1 hour, and then lowered to room temperature at a cooling rate of 5°C / min. / Titanium carbide composite powder. Electron microscopy (SEM) showed that the final Fe / TiC composite powder had the characteristics of titanium carbide uniformly distributed in the iron phase, and the particle size of TiC was about 5 μm; nitrogen and oxygen analysis showed that the oxygen content of the product was lower than 2wt.%. ; The mass fraction of TiC in the obtained Fe / TiC composite powder is 75wt.%.

Embodiment 3

[0025] Embodiment 3 is basically the same as Embodiment 1, the difference is:

[0026] To analyze pure TiO 2 , activated carbon, iron oxide powder as raw materials, according to TiO 2 , C, Fe 2 o 3 The mass ratio is 20:20.25:50, and then use the agitator to mix the prepared raw materials evenly. Press the mixed raw materials under the pressure of 250Mpa to form a block with a press, and put the block into a vacuum furnace. , heated to 1300°C at a heating rate of 5°C / min, kept for 2 hours, and then lowered to room temperature at a cooling rate of 5°C / min. Powder. Electron microscopy (SEM) showed that the finally obtained Fe / TiC composite powder had the characteristics of uniform distribution of titanium carbide in the iron phase, and the particle size of TiC was about 0.5 μm; nitrogen and oxygen analysis showed that the oxygen content of the product was lower than 1wt. %; The mass fraction of TiC in the obtained Fe / TiC composite powder is 30wt.%.

technical field

[0001] The invention belongs to the field of composite materials and hard alloys, and in particular relates to a preparation method of Fe / TiC composite powder. Background technique

[0002] In recent years, ceramic-metal composites have become a current research hotspot because of their excellent wear resistance and hardness, as well as their excellent specific modulus and strength. Steel-bonded cemented carbide first appeared in the early 1960s and is an innovative ceramic-metal composite material that combines the properties of steel and carbide. Among various carbides, titanium carbide has a NaCl type cubic crystal structure, the unit cell parameter is 0.4327nm, and the space group is Fm3m. It has the characteristics of high melting point, high hardness, wear resistance and corrosion resistance, and also has good thermal conductivity. It is a promising cermet reinforcement material because of its high conductivity, electrical conductivity and chemical sta...

Examples

Embodiment 1

[0020] The present invention analyzes pure TiO 2 , graphite, electrolytic iron powder as raw materials, according to TiO 2 , C, Fe mass ratio is the ratio batching of 20:9:15, then utilizes the stirrer to mix the prepared raw material evenly, under the pressure of 230Mpa, the mixed raw material is pressed into a block with a press, and the block is placed Put it into a vacuum furnace, heat it up to 1400°C at a heating rate of 5°C / min, keep it warm for 1.5 hours, and then lower it to room temperature at a cooling rate of 5°C / min. During this period, the pressure of the vacuum furnace is kept at 10Pa. / Titanium carbide composite powder. X-ray diffraction (XRD) analysis shows that the product phase is α-Fe and TiC, and there is no other phase; electron microscope (SEM) shows that the finally obtained Fe / TiC composite powder has titanium carbide uniformly distributed in the iron phase. characteristics, and the particle size of TiC is about 2μm; nitrogen and oxygen analysis shows...

Embodiment 2

[0022] Embodiment 2 is basically the same as Embodiment 1, the difference is:

[0023] To analyze pure TiO 2 , carbon black, and electrolytic iron powder as raw materials, according to TiO 2 , C, Fe mass ratio is 20:9:5 ratio batching, then use agitator to mix the prepared raw materials evenly, with the mixed raw materials under 150Mpa pressure, press into a block with a press, put the block into a vacuum furnace, heated to 1500°C at a heating rate of 5°C / min, kept for 1 hour, and then lowered to room temperature at a cooling rate of 5°C / min. / Titanium carbide composite powder. Electron microscopy (SEM) showed that the final Fe / TiC composite powder had the characteristics of titanium carbide uniformly distributed in the iron phase, and the particle size of TiC was about 5 μm; nitrogen and oxygen analysis showed that the oxygen content of the product was lower than 2wt.%. ; The mass fraction of TiC in the obtained Fe / TiC composite powder is 75wt.%.

Embodiment 3

[0025] Embodiment 3 is basically the same as Embodiment 1, the difference is:

[0026] To analyze pure TiO 2 , activated carbon, iron oxide powder as raw materials, according to TiO 2 , C, Fe 2 o 3 The mass ratio is 20:20.25:50, and then use the agitator to mix the prepared raw materials evenly. Press the mixed raw materials under the pressure of 250Mpa to form a block with a press, and put the block into a vacuum furnace. , heated to 1300°C at a heating rate of 5°C / min, kept for 2 hours, and then lowered to room temperature at a cooling rate of 5°C / min. Powder. Electron microscopy (SEM) showed that the finally obtained Fe / TiC composite powder had the characteristics of uniform distribution of titanium carbide in the iron phase, and the particle size of TiC was about 0.5 μm; nitrogen and oxygen analysis showed that the oxygen content of the product was lower than 1wt. %; The mass fraction of TiC in the obtained Fe / TiC composite powder is 30wt.%.