Al-25Si Hypereutectic Al-Si Alloys For Top-level Vehicle Cylinder Liners

- Jul 25, 2018-

Tianjin Baienwei New Material Technology Co.,Ltd develops,produces and sells the silicon-aluminum(Al-Si) alloys with the outstanding physical and mechanical properties.We are now offering the expectional cylinder sleeves(tube billets) to our Europe commercial customers.It will be difficult to find the high reliable and trustworthy supplier which can delivery the leading edge aluminum alloys material and service for companies.Any other size also can be customized according to client’s requirement.

The properties of hypereutectic Al-Si alloy,encompassing the casting performance,mechanical property,abrasion property and cutting machining.

Casting Property

A large amount of latent heat is released when the primary silicon precipitate out,the commonly used eutectic al-si alloy has better fluidity than eutectic alloy.However, liquidity will begin to decline after the Si content exceeds 18%. As the silicon content in the alloy increases, the linear shrinkage decreases.While with the expansion of the crystallization temperature range, some casting defects will gradually appear, such as alloy shrinkage tendency increases, reduced air tightness, that is, casting performance.

Mechanical Property

The alloys can obtain the satified mechanical properties if through the matchable modification.As the temperature increases,the alloy strength reduction but improve the ductility. Under the condition of select suitable composition and modification treatment,the high temperature strength of hypereutectic Al-Si alloy is superior than that of eutectic alloy. 

Abrasion Resistance

As the increase of silicon content,the primary silicon volume percentage will increase in the alloy,so that improve the abrasion resistance of the alloy.

Comparation to the cocrystallizing type and eutectic alloy, the wear rate of hypereutectic of Al-Si alloy is 0.3~0.5 times than hypoeutectic alloy,is 0.1~0.2 times than that of eutectic alloy.In general,the hypereutectic Al-Si alloy has excellent wear-resistance.

Cutting Machining

Owing to the tool is worn very easily and roughness surface.The solution to this problem is to use the diamond tools,or add a little lead(Pb) or bismuth(Bi) in the alloy composition.

High Temperature Strength and Dimensional Stability

The current research focuses on the hypereutectic alloys with silicon content below 30%. Due to its high thermal conductivity and controllable thermal expansion coefficient, high-silicon aluminum alloys are used in electronic packaging materials,e.g 27Si-73Al to 70Al-30Al controlled expansion alloy.

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Mechanical properties of hypereutectic Al-25%Si alloy is as below,

Mechanical Properties of hypereutectic Al-25Si alloy

Material

Density
(g/cm3)

Tensile
Strength
(MPa)

 Yield
  Strength
 (MPa)

Poisson's
 Ratio

Elongation
(%)

Elastic
Modulus
(GPa)

Hardness
(HB)

Al-25%Si

2.64

480

441

0.29

0.7

96

2.6