CN101073860A - Welding wire of melt welding filling flux for granular enhanced aluminum-based composite material - Google Patents

Abstract

The welding wire used for the fusion welding of particle-reinforced aluminum matrix composite materials, involving the field of new welding materials, the relative proportion (mass fraction) of each component should be as follows: Ti: 5% to 20%; Si, Mg, rare earth Ce or La One or more of them can be selected arbitrarily, and the respective contents should reach: Si 3%-7%, Mg 3%-7%, rare earth Ce or La 0.5%-1.5%; the rest Al. The invention has good welding manufacturability, can be welded under Ar, He and other gas-protected fusion welding, has high mechanical properties of the welded metal, and has the advantages of beautiful shape, small spatter, no air holes, and all-round welding.

Description

Flux-filled wire for fusion welding of particle-reinforced aluminum matrix composites

technical field

The invention relates to the field of new welding materials, in particular alloy welding wire for fusion welding of particle-reinforced aluminum-based composite materials, and is mainly used for fusion-welding of particle-reinforced aluminum-based composite materials. The invention can effectively suppress the formation of needle-like brittle phases in weld seams , form well-shaped welds, reduce the generation of pores, and obtain good mechanical properties.

Background technique

Fusion welding is the welding method with the widest application range, the strongest adaptability, the easiest operation and the most mature technology among the welding methods used. The research direction of fusion welding of aluminum matrix composites has high research value. If a breakthrough is found in this respect, the industrialization process of aluminum matrix composites will be greatly accelerated, which is of great significance for promoting the development of science and technology in our country, realizing the scientific and technological goals of the "Eleventh Five-Year Plan" and national defense modernization.

At present, the following problems exist in the fusion welding of particle reinforced aluminum matrix composites:

1) A large number of reinforcing phases such as SiC particles exist in the molten liquid matrix, causing viscosity, so that the matrix material and the filler wire material are not fused together, especially when the SiC content is high, it is more serious, resulting in inclusions and affecting normal forming; in addition , The viscous molten pool metal is not conducive to the diffusion and escape of hydrogen, and a large number of pores are formed in the weld.

2) The wettability between the reinforced phase SiC and the Al matrix is poor. When no filler metal is used, under the action of strong arc heat, Al is pushed from the center of the molten pool to the edge under the action of the arc force, and it is not easy to form a stable welded pool. , the performance of welded joints is degraded.

2) The matrix Al in the composite material is a very active chemical element. It is easy to react with the reinforcing material under high temperature conditions and form brittle compounds at the interface. For example, SiC _p /Al will generate Al ₄ C ₃ and distribute on the SiC interface. It greatly weakens the effect of the reinforcing phase and reduces the strength of the joint near the seam.

3) In the process of melting and crystallization, the reinforcing phase SiC cannot become the crystal core, and is repelled by the crystals in the weld at the center or fusion line, which can easily cause crystal cracks in the center of the weld and the weld toe, and cause embrittlement of the weld structure. Layer, greatly reducing the joint strength.

4) There are significant differences in physical properties such as thermal conductivity and thermal expansion coefficient between the matrix and the reinforcement phase of the composite material. After a strong welding thermal cycle, a large amount of residual stress in the micro-area is generated on the interface between the matrix and the reinforcement, which reduces the performance of the joint.

Weld in-situ alloying method Welding particle reinforced aluminum matrix composites is a recently proposed method with relatively high feasibility. By adding alloy welding wire instead of direct welding or adding aluminum alloy, the problems in the welding process can be solved , adding corresponding interfacial reaction inhibiting elements, active elements reducing porosity, etc., inhibited the occurrence of harmful interfacial reactions, regenerated a new reinforcing phase in the weld, greatly reduced the number of pores in the solidification zone of the weld, and refined Reinforced particles increase the tensile strength of the weld and obtain a welded joint with good mechanical properties.

Welding in-situ alloying of welded particle-reinforced aluminum matrix composites requires a welding wire as a filler material. Therefore, in order to solve the above problems, the key to the realization of aluminum matrix composites is to invent a welding wire.

According to the literature search of the prior art, it is found that there is no relevant patent application in China at present.

Contents of the invention

The object of the present invention is to provide a welding wire applied to the fusion welding of particle reinforced aluminum matrix composite materials, to effectively suppress the harmful interface reaction in the welding process, form a well-shaped weld, reduce the generation of pores, and improve the weld structure. mechanical properties. The invention prepares effective alloy elements into alloy welding wire according to the ratio.

In the welding wire for fusion welding of particle reinforced aluminum matrix composite materials, the relative specific gravity (mass fraction) of each component should be as follows:

Ti: 5% to 20%;

Select one or more of Si, Mg, rare earth Ce or La arbitrarily, each content should reach: Si3%～7%, Mg3%～7%, rare earth Ce or La0.5%～1.5%; the rest Al.

That is, Ti: 5% to 20%; Si3% to 7%; the rest Al.

Ti: 5%-20%; Mg3%-7%, the rest Al.

Ti: 5% to 20%; rare earth Ce or La0.5% to 1.5%; the rest Al

Ti: 5%-20%; Si3%-7%; Mg3%-7%; the rest Al.

Ti: 5%-20%; Si3%-7%; rare earth Ce or La0.5%-1.5%; the rest Al.

Ti: 5%-20%; Mg3%-7%; rare earth Ce or La0.5%-1.5%; the rest Al.

Ti: 5% to 20%; Si3% to 7%; Mg3% to 7%, rare earth Ce or La0.5% to 1.5%, and the rest Al.

The mass fraction of Ti in the above welding wire is preferably 10%, Si and Mg are preferably 5%, and the rare earth Ce or La is preferably 1%.

The present invention has the following advantages:

1) The welding wire has good welding processability, and can be welded under the shielded melting welding of Ar, He and other gases. The mechanical properties of the welded metal are high, and it also has the advantages of beautiful shape, small spatter, no air holes and all-round welding. .

2) The welding wire makes full use of the rich rare earth metals in our country, is based on the domestic market, and has sufficient raw material supply. Therefore, the cost is low and good social and economic benefits can be obtained.

Description of drawings

The microstructure of the weld in Fig. 1 Comparative Example 1

Fig. 2 XRD analysis diagram of weld seam in comparative example 1

The weld microstructure diagram of Fig. 3 embodiment 1

The weld XRD analysis figure of Fig. 4 embodiment 1

Detailed ways

Adopting the welding wire of the invention as SiCp/Al composite material fusion welding can effectively suppress the harmful interface reaction in the welding process, form a well-shaped welding seam, reduce the generation of pores, and improve the mechanical properties of the welding seam structure.

In order to obtain these characteristics, the present invention prepares the above-mentioned elements that can improve the weldability of the aluminum-based composite material into alloy welding wire in proportion. In view of the many problems in the fusion welding of aluminum matrix composites, it is necessary to add different elements with corresponding inhibitory effects, not only to adjust the composition of the welding wire, but also to control the ratio of each component.

Comparative example 1

For SiCp/6061 composite material, before welding, use 150 ^# sandpaper to polish the base metal to remove the oxide film, and then clean it with acetone. After the sample is dried at 150°C, argon + 30% nitrogen is used as the ion gas, the ion gas flow rate is 3L/min, protected by pure argon, the welding current is 50A, and the welding speed is 150mm/min. Direct butt welding of composite materials. Sampling and analysis of welded joints after welding, comprehensive analysis of Figure 1 and Figure 2, it can be seen that the reinforcement phase SiC particles in the weld pool have been completely dissolved in the process of direct plasma arc melting welding, and precipitated in the subsequent solidification process A large amount of fine Al ₄ C ₃ , a large number of large pores are formed in the semi-melted zone of the weld. The tensile strength of the welded joint is tested on an electronic universal testing machine, and the tensile strength of the welded joint is only 130MPa.

Example 1

For SiCp/6061 composite material, before welding, use 150 ^# sandpaper to polish the base metal to remove the oxide film, and then clean it with acetone. After the sample is dried at 150°C, argon + 30% nitrogen is used as the ion gas, the ion gas flow rate is 3L/min, protected by pure argon, the welding current is 100A, and the welding speed is 150mm/min. During the welding process, an Al-10%Ti-5%Mg alloy wire with a diameter of 1mm is added to the weld pool at a speed of 200mm/min. After welding, the welded joints were sampled and analyzed. From Figure 3 and Figure 4, it can be seen that reinforcing particles such as TiC, TiN, AlN, Al ₃ Ti, MgAl ₂ O ₄ and Mg ₃ N ₂ were formed at the welded joints, and the size of the particles was between Below 4μm, the particle distribution is uniform, and the tensile strength of the welded joint is about 250MPa, which meets the strength requirements of the welded joint. It can be seen from Figure 4 that the composition analysis shows that the average content of Ti and Mg elements in the welded joint is 3.12% and 1.62%.

Example 2

For SiCp/6061 composite material, before welding, use 150 ^# sandpaper to polish the base metal to remove the oxide film, and then clean it with acetone. After the sample is dried at 150°C, argon + 30% nitrogen is used as the ion gas, the ion gas flow rate is 3L/min, protected by pure argon, the welding current is 100A, and the welding speed is 150mm/min. During the welding process, an Al-20%Ti-5%Si alloy wire with a diameter of 1mm is added to the weld pool at a speed of 200mm/min. After welding, the welded joints were sampled and analyzed, and the results showed that reinforcing particles such as TiC, TiN, AlN, and Al ₃ Ti were formed at the welded joints. The size of the particles was below 5 μm, and the particle distribution was uniform. The tensile strength of the welded joints was about 230 MPa. Meet the strength requirements of welded joints. Composition analysis shows that the average content of Ti and Si elements in the welded joint part is 6.2% and 1.51%.

Example 3

For SiCp/6061 composite material, before welding, use 150 ^# sandpaper to polish the base metal to remove the oxide film, and then clean it with acetone. After the sample is dried at 150°C, argon + 30% nitrogen is used as the ion gas, the ion gas flow rate is 3L/min, protected by pure argon, the welding current is 100A, and the welding speed is 120mm/min. During the welding process, an Al-10%Ti-5%Si-5%Mg-1%Ce alloy wire with a diameter of 1mm is added to the weld pool at a speed of 200mm/min. After welding, the welded joints were sampled and analyzed, and the results showed that reinforcing particles such as TiC, TiN, AlN, Al ₃ Ti, MgAl ₂ O ₄ and Mg ₃ N were formed at the welded joints, and the size of the particles was 0.2-3 μm, and the particle distribution was uniform. The tensile strength of the welded joint is about 250MPa, which meets the strength requirements of the welded joint. Compositional analysis shows that the average contents of Ti, Si, Mg, and Ce elements in the welded joints are 3.2%, 2.2%, 1.5%, and 0.21%.

Example 4

For Al ₂ O ₃ P/A356 composite material, before welding, use 150 ^# sandpaper to polish the base metal to remove the oxide film, and then clean it with acetone. After the sample is dried at 150°C, argon + 20% nitrogen is used as the ion gas, the ion gas flow rate is 4L/min, protected by pure argon, the welding current is 100A, and the welding speed is 120mm/min. During the welding process, an Al-10%Ti-5%Si-1%Ce alloy wire with a diameter of 1mm is added to the weld pool at a speed of 220mm/min. After welding, the welded joints were sampled and analyzed, and the results showed that: TiN and Al ₃ Ti reinforced particles were formed at the welded joints, the particle size was 0.5-2μm, and the particle distribution was uniform. The tensile strength of the welded joint was about 240MPa, which met the requirements of the welded joint. strength requirements. Composition analysis shows that the average contents of Ti, Si and Ce elements in the welded joints are 2.51%, 2.3%, and 0.16%.

Claims (2)

1, be used for the welding wire of the melt welding filling flux of particle enhanced aluminum-based composite material, it is characterized in that: each component is calculated with mass percent:

Ti：5％～20％；

Choose one or more arbitrarily among Si, Mg, Rare-Earth Ce or the La, content should reach separately: Si 3%～7%, and Mg 3%～7%, Rare-Earth Ce or La0.5%～1.5%; All the other Al;

It is Ti:5%～20%; Si 3%～7%; All the other Al;

Ti:5%～20%; Mg 3%～7%; All the other Al;

Ti:5%～20%; Rare-Earth Ce or La0.5%～1.5%, all the other Al;

Ti:5%～20%; Si 3%～7%; Mg3%～7%; All the other Al;

Ti:5%～20%; Si 3%～7%; Rare-Earth Ce or La0.5%～1.5%; All the other Al;

Ti:5%～20%; Mg 3%～7%; Rare-Earth Ce or La0.5%～1.5%; All the other Al;

Ti:5%～20%; Si 3%～7%; Mg 3%～7%, Rare-Earth Ce or La0.5%～1.5%, all the other Al.

2, the welding wire that is used for the melt welding filling flux of particle enhanced aluminum-based composite material according to claim 1 is characterized in that: the mass fraction of Ti is 10% in the welding wire, and Si, Mg are 5%, and Rare-Earth Ce or La are 1%.

Images