Method for in-situ preparation of TiBO2 reinforced magnesium-based composite material

Abstract

The invention relates to a method of in-situ preparing TiB2 granule strengthening Mg-based composite material in the composite material technical field. The steps are that: powder of K2TiF6, KBF4 and Na3AlF6 are mixed uniformly and then put into a kiln for drying, thus obtaining waterless powder. Aluminum ingot is melted in a resistance furnace with heat preservation and uniformity; the waterless powder after dried is added to the melting Al melt liquid by batch and then is stirred with a graphite disc, and scum on the surface of the melt liquid is removed after stirred and stewed, thus obtaining TiB2-Al intermediate alloy; magnesium alloy is smelted with the protection of SF6 and CO2 mixing gas, and flame retardant element beryllium is added; the TiB2-Al intermediate alloy is added into the magnesium alloy melting solution slowly, stirred, stewed and cast. The technology of the invention is comparatively simple, has low cost, and the density of TiB2 / Mg composite material is between 1.8-2.0g / cm<3> and tensile strength thereof is increased by more than 60 percent than base alloy.

Description

technical field

[0001] The invention relates to a preparation method in the technical field of composite materials, in particular to an in-situ preparation of TiB 2 Method for Particle Reinforcement of Magnesium Matrix Composites. Background technique

[0002] Due to its high specific strength, specific modulus, good wear resistance, high temperature resistance and damping performance, magnesium-based composite materials have potential application prospects and broad markets in the aerospace and automotive industries. The previous research work on magnesium-based composites mainly focused on the magnesium-based composites prepared by the external addition method. However, due to the poor wettability between the reinforcement and the matrix alloy, the interface between the reinforcement phase and the matrix is ​​thermodynamically unstable. Due to the difference in specific gravity, the particles are easy to segregate and aggregate during the preparation of composite material...

Examples

Embodiment 1

[0021] Preparation of 4vol% TiB 2 Reinforced magnesium matrix composites

[0022] Powder K 2 TiF 6 and KBF 4 and cryolite Na 3 AlF 6 well mixed. Two kinds of salt K 2 TiF 6 and KBF 4 Mixed according to the stoichiometric ratio of Ti:B 1:2, cryolite Na 3 AlF 6 The content is 5wt% of the total amount of powder, and preheated at 250°C for 1 hour after mixing. The metal aluminum ingot is heated to about 850°C to melt, and is kept homogenized for 10 minutes. The mixed powder was added into the molten aluminum and stirred at a speed of 200r / min for 60 minutes. After the stirring is stopped, let it stand for 20 minutes, remove the slag, and obtain TiB 2 -Al master alloy. Magnesium Alloys in Mixed Gas SF 6 and CO 2 It is melted at 800°C under the protection of protection. After melting the magnesium alloy, TiB 2 -Al master alloy is slowly added to the magnesium alloy. Implement stirring, the stirring speed is 200r / min, and the stirring time is 30 minutes. After sti...

Embodiment 2

[0024] Preparation of 2vol%TiB 2 Reinforced magnesium matrix composites

[0025] Will K 2 TiF 6 and KBF 4 and cryolite Na 3 AlF 6 The powder is mixed well. Two kinds of salt K 2 TiF 6 and KBF 4 Mixed according to the stoichiometric ratio of Ti:B 1:2, cryolite Na 3 AlF 6 The content is 20wt% of the total amount of powder, and preheated at 100°C for 5 hours after mixing. The Al ingot is heated to about 800°C to melt, and is kept homogenized for 30 minutes. The mixed powder is added to the molten aluminum with constant stirring. The stirring time is 10min, and the stirring speed is 1000rpm. After the stirring is stopped, let it stand for 10 minutes, remove the slag, and obtain TiB 2 -Al master alloy. Magnesium Alloys in Mixed Gas SF 6 and CO 2 It is melted at 700°C under the protection of protection. After melting the magnesium alloy, TiB 2 - The Al master alloy is slowly added to the constantly stirring magnesium alloy. Stir for 10 minutes at a stirring speed...

Embodiment 3

[0027] Preparation of 1vol% TiB 2 Reinforced magnesium matrix composites

[0028] Will K 2 TiF 6 and KBF 4and cryolite Na 3 AlF 6 The powder is mixed well. Two kinds of salt K 2 TiF 6 and KBF 4 Mixed according to the stoichiometric ratio of Ti:B 1:2, cryolite Na 3 AlF 6 The content is 10wt% of the total amount of mixed powder, and preheated at 200° C. for 3 hours after mixing. The Al ingot is heated to about 700°C to melt, and is kept homogenized for 20 minutes. The mixed powder is added to the molten aluminum and stirred. The stirring time is 30min, and the stirring speed is 400rpm. Stop stirring after the reaction, let it stand for 30 minutes, remove the slag, and obtain TiB 2 -Al master alloy. Magnesium Alloys in Mixed Gas SF 6 and CO 2 It is melted at 850°C under the protection of protection. After melting the magnesium alloy, TiB 2 -Al master alloy is slowly added to the molten magnesium alloy. Stir for 60 minutes at a stirring speed of 600 rpm. After...

technical field

[0001] The invention relates to a preparation method in the technical field of composite materials, in particular to an in-situ preparation of TiB 2 Method for Particle Reinforcement of Magnesium Matrix Composites. Background technique

[0002] Due to its high specific strength, specific modulus, good wear resistance, high temperature resistance and damping performance, magnesium-based composite materials have potential application prospects and broad markets in the aerospace and automotive industries. The previous research work on magnesium-based composites mainly focused on the magnesium-based composites prepared by the external addition method. However, due to the poor wettability between the reinforcement and the matrix alloy, the interface between the reinforcement phase and the matrix is ​​thermodynamically unstable. Due to the difference in specific gravity, the particles are easy to segregate and aggregate during the preparation of composite material...

Examples

Embodiment 1

[0021] Preparation of 4vol% TiB 2 Reinforced magnesium matrix composites

[0022] Powder K 2 TiF 6 and KBF 4 and cryolite Na 3 AlF 6 well mixed. Two kinds of salt K 2 TiF 6 and KBF 4 Mixed according to the stoichiometric ratio of Ti:B 1:2, cryolite Na 3 AlF 6 The content is 5wt% of the total amount of powder, and preheated at 250°C for 1 hour after mixing. The metal aluminum ingot is heated to about 850°C to melt, and is kept homogenized for 10 minutes. The mixed powder was added into the molten aluminum and stirred at a speed of 200r / min for 60 minutes. After the stirring is stopped, let it stand for 20 minutes, remove the slag, and obtain TiB 2 -Al master alloy. Magnesium Alloys in Mixed Gas SF 6 and CO 2 It is melted at 800°C under the protection of protection. After melting the magnesium alloy, TiB 2 -Al master alloy is slowly added to the magnesium alloy. Implement stirring, the stirring speed is 200r / min, and the stirring time is 30 minutes. After sti...

Embodiment 2

[0024] Preparation of 2vol%TiB 2 Reinforced magnesium matrix composites

[0025] Will K 2 TiF 6 and KBF 4 and cryolite Na 3 AlF 6 The powder is mixed well. Two kinds of salt K 2 TiF 6 and KBF 4 Mixed according to the stoichiometric ratio of Ti:B 1:2, cryolite Na 3 AlF 6 The content is 20wt% of the total amount of powder, and preheated at 100°C for 5 hours after mixing. The Al ingot is heated to about 800°C to melt, and is kept homogenized for 30 minutes. The mixed powder is added to the molten aluminum with constant stirring. The stirring time is 10min, and the stirring speed is 1000rpm. After the stirring is stopped, let it stand for 10 minutes, remove the slag, and obtain TiB 2 -Al master alloy. Magnesium Alloys in Mixed Gas SF 6 and CO 2 It is melted at 700°C under the protection of protection. After melting the magnesium alloy, TiB 2 - The Al master alloy is slowly added to the constantly stirring magnesium alloy. Stir for 10 minutes at a stirring speed...

Embodiment 3

[0027] Preparation of 1vol% TiB 2 Reinforced magnesium matrix composites

[0028] Will K 2 TiF 6 and KBF 4and cryolite Na 3 AlF 6 The powder is mixed well. Two kinds of salt K 2 TiF 6 and KBF 4 Mixed according to the stoichiometric ratio of Ti:B 1:2, cryolite Na 3 AlF 6 The content is 10wt% of the total amount of mixed powder, and preheated at 200° C. for 3 hours after mixing. The Al ingot is heated to about 700°C to melt, and is kept homogenized for 20 minutes. The mixed powder is added to the molten aluminum and stirred. The stirring time is 30min, and the stirring speed is 400rpm. Stop stirring after the reaction, let it stand for 30 minutes, remove the slag, and obtain TiB 2 -Al master alloy. Magnesium Alloys in Mixed Gas SF 6 and CO 2 It is melted at 850°C under the protection of protection. After melting the magnesium alloy, TiB 2 -Al master alloy is slowly added to the molten magnesium alloy. Stir for 60 minutes at a stirring speed of 600 rpm. After...