High volume fractional endogenous granular reinforced aluminum base composite material and preparation method thereof
Technical field
The present invention relates to particulate reinforced composite and preparation method thereof.Specifically, the present invention relates to utilize spontaneous silicon grain+endogenetic particle (Si+Al of high-volume fractional (more than 30%)
2O
3+ Al
3Zr+ZrB
2) compound enhanced aluminum matrix composite and preparation method thereof.
Background technology
Particle enhanced aluminum-based composite material has the specific tenacity height, strengthen that the body cost is low, microtexture evenly, material property isotropy, advantage such as can adopt that conventional machining process is processed, become one of important development direction of metal-base composites.Particle enhanced aluminum-based composite material can be divided into according to the source of enhanced granule wherein and adds particle enhanced aluminum-based composite material and the synthetic particle enhanced aluminum-based composite material of reaction.
In many application scenarios, require the aluminum matrix composite of exploitation high-volume fractional (more than 30%) enhanced granule.For example, be used for the SiC particle enhanced aluminum-based composite material of automobile brake disc, SiC particulate volume fraction is about 30-50%.Adopt such matrix material can make the original ironcasting of weight ratio of automobile brake disc alleviate 50-60%, braking distance shortens, and the brake flange heat-shock resistance improves, and makes braking ability stable.But, owing to add the SiC particle and liquid Al is nonwetting, and have surface reaction, so SiC particle enhanced aluminum-based composite material plasticity low (being not more than 0.3%), crack propagation are fast, can cause under shear-stress fatigue cracking to be expanded fast, may cause burst accident.Usually, these crackles are easy to expand in adding the SiC particle enhanced aluminum-based composite material.This is that it is big to exist particle size owing to add that enhanced granule is added by the outside in the particle enhanced aluminum-based composite material, and particle surface has pollution, and the interface is in conjunction with poor, and easily generates a series of shortcomings such as fragility by product.
Endogenetic particle strengthens in-situ composite (In-situ Composites), is meant that it strengthens body original position forming core, thermodynamically stable phase of growing up from metallic matrix (being generally Al).Therefore, the enhancing surface is pollution-free, has avoided the problem bad with the matrix consistency, and the interface bond strength height.Thereby be described as and have breakthrough new technology and extremely pay attention to, become a new focus in the research of metal matrix (particularly aluminium base) matrix material.The original position synthetic technology mainly contains XD at present
TMMethod, DIMOX
TMMethod, PRIMEX
TMMethod, VLS method, LSM method, SHS method, CR method, MA method, melting-reaction method (Direct Melt Reaction; DMR) etc.; wherein; melting-reaction method is that solid particulate or the powder that will contain the enhanced granule forming element join in the fused aluminum or aluminum alloy under a certain temperature; make it abundant reaction; thereby the preparation endogenous granular reinforced aluminum base composite material, and can directly pour into a mould complex-shaped foundry goods.Thereby, have that technology is simple, cost is low, the cycle is short, be easy to advantages such as suitability for industrialized production, and be considered to realize one of new technology of industrial applications.But endogenous granular reinforced aluminum base composite material is defectiveness also, is that mainly its synthetic grain volume fraction is usually less than 15vol%, and the braking automobile hub uses the volume fraction of particle enhanced aluminum-based composite material to require at 30~50vol%.Therefore, the volume fraction that how to improve endogenetic particle is the key of dealing with problems.
Therefore, exploitation had both possessed the advantage of high thermal conductivity and high-wearing feature, possessed the endogenous granular reinforced aluminum base composite material of good plasticity again, was the important content of high-volume fractional aluminum matrix composite exploitation.The present invention proposes to utilize spontaneous silicon grain+endogenetic particle (Si+Al
2O
3+ Al
3Zr+ZrB
2) compound reinforced aluminum matrix composites, this technology does not still have relevant report at home and abroad.
Summary of the invention
The present invention generates (Al with reaction in synthetic technology and rotten composite treatment technology of primary silicon refinement and the integrated silumin that is applied to of electromagnetic field processing by molten aluminium and reactant reaction
2O
3+ ZrB
2+ Al
3Zr) particle, and in process of setting, produce a large amount of tiny Si particles through phosphorus-rare earth Combined Processing by silumin, thus form the high-volume fractional enhanced granule of 30%~50vol%.
A kind of high volume fractional endogenous granular reinforced aluminum base composite material is characterized in that: comprise Al in the aluminum substrate simultaneously
3Zr, ZrB
2And Al
2O
3Particle and tiny Si particle, wherein particulate theoretical volume mark is 30~50%.
A kind of preparation method of high volume fractional endogenous granular reinforced aluminum base composite material, adopt the preparation of melt direct reaction method, it is characterized in that: the particle intensified response thing that in containing the silumin melt of 18-26wt%Si, adds the 20wt%~30wt% that accounts for aluminium liquid quality, temperature of aluminum liquid is between 850~950 ℃, add the rotten composite treating agent of the refinement that accounts for aluminium liquid quality 0.08~0.12wt%P+0.8~1.0wt%RE (rare earth) behind question response 20min~40min again, treatment time is 10min~20min, leave standstill 5min~10min then, be cooled to 760~780 ℃ and pour into to solidify in the metal mold and obtain heterogeneous endogenetic particle (Si+Al
2O
3+ ZrB
2+ Al
3Zr) reinforced aluminum matrix composites.According to different needs, can direct production foundry goods or production ingot casting.
Particle intensified response thing is ZrSiO
4And B
2O
3Mixture, Zr (CO
3)
2And B
2O
3Mixture or ZrOCl
2And B
2O
3A kind of in the mixture, and Zr: B=1 in molar ratio: 2 mix.
When adding reaction mixture, carry out induction stirring and handle, electric current I=150A, frequency f=4Hz, magnetic induction density B=0.032mT can be so that endogenetic particle be evenly distributed.
The present invention has following advantage:
1, because the silicone content in the silumin can be adjusted within the specific limits, utilize the volume fraction of the in-situ particle of fusant reaction technology preparation also can change within the specific limits simultaneously, so the designability of such matrix material is strong.
2, because the primary silicon particle and the in-situ particle that generate are endogenetic particle, and good with the Al wettability, but and once shaped, so preparation technology is simple, cost is low, and not only have high strength, high-wearing feature, high heat resistance, and have toughness preferably.
3, separate out owing to producing a large amount of primary silicons in the process of setting, improved the volume fraction of enhanced granule; And the primary silicon particulate is of a size of, and 25 μ m are following to be of a size of the following size that forms of 5 μ m with in-situ particle and to distribute alternately, improved the density of matrix material, produced simultaneously particle is endogenetic particle, so the interface bond strength of particle and matrix is effectively guaranteed in the matrix material, therefore, prepared matrix material has higher stability.
Embodiment
Embodiment 1
With high silicon Al-18%Si alloy melting, about 850 ℃, add the reactant that accounts for alloy mass 20%, reactant is Zr (CO
3)
2+ B
2O
3And Zr: B=1 in molar ratio: 2 mix, and carry out induction stirring simultaneously and handle electric current I=150A, frequency f=4Hz, magnetic induction density B=0.032mT adds the rotten composite treating agent of the refinement that accounts for aluminium liquid quality 0.08wt%P+0.8wt%Ce again behind the question response 20min, the treatment time is 10min, leave standstill 5min then, melt after handling is cooled to 760 ℃ directly pours into ingot casting, after testing, the volume fraction of enhanced granule is about 31.2% in this matrix material.
Embodiment 2
With high silicon Al-24%Si alloy melting, about 900 ℃, add the reactant that accounts for alloy mass 25%, reactant is ZrSiO
4+ B
2O
3And Zr: B=1 in molar ratio: 2 mix, carry out induction stirring simultaneously and handle electric current I=150A, frequency f=4Hz, magnetic induction density B=0.032mT, add the rotten composite treating agent of the refinement that accounts for aluminium liquid quality 0.1wt%P+0.9wt%Ce behind the question response 30min again, the treatment time is 15min, leaves standstill 8min then, melt after handling is cooled to 780 ℃ pours into automobile brake disc by extrusion casting. after testing, the volume fraction of enhanced granule is about 42.6%. in this matrix material
Embodiment 3
With the Al-26%Si alloy melting, about 950 ℃, add the reactant that accounts for alloy mass 30%, reactant is ZrOCl
2+ B
2O
3And Zr: B=1 in molar ratio: 2 mix, carrying out induction stirring simultaneously handles, electric current I=150A, frequency f=4Hz, magnetic induction density B=0.032mT, add the rotten composite treating agent of the refinement that accounts for aluminium liquid quality 0.12wt%P+1.0wt%Ce behind the question response 40min again, treatment time is 20min, leaves standstill 10min then, the melt after handling is cooled to 780 ℃ pours into ingot casting.After testing, the volume fraction of enhanced granule is about 49.8% in this matrix material.