AlSi12 Powder

Overview of AlSi12 Powder

AlSi12 or A413 is an aluminum casting alloy with relatively high silicon content. The addition of 12% silicon results in good wear resistance, low coefficient of thermal expansion, and high thermal conductivity.

Key properties of AlSi12 powder include:

• Good strength and hardness
• Excellent wear resistance
• Good dimensional stability
• High thermal conductivity
• Good machinability and polishability
• Low specific gravity
• Available in various particle size distributions

AlSi12 is used for producing cylinder liners, piston rings, rocker arms, connecting rods, parts requiring heat and wear resistance. The powder metallurgy approach enables complex geometries.

Composition of AlSi12 Powder

The typical composition of AlSi12 powder is:

Aluminum provides the matrix while silicon is the principal alloying element. Trace amounts of other elements can be present. The high silicon content results in the special properties of this alloy.

Properties of AlSi12 Powder

AlSi12 powder possesses the following properties:

The silicon additions result in higher strength, hardness, wear resistance, and thermal conductivity compared to unalloyed aluminum. The material retains good ductility and machinability.

Production Method for AlSi12 Powder

AlSi12 powder is manufactured by:

• Gas Atomization – High pressure inert gas jets atomize molten AlSi12 alloy to form spherical powders. This produces powder with smooth morphology and narrow size distribution suitable for AM.
• Water Atomization – High velocity water jets hit the molten metal stream to produce fine irregular AlSi12 particles. Lower cost but higher oxygen pickup.
• Mechanical Milling – Ball milling of aluminum and silicon powders followed by blending, compacting and sintering. Leads to wide size distribution.

Gas atomization is preferred when spherical powder with controlled characteristics is required such as for additive manufacturing or MIM. Mechanical milling route is lower cost.

Applications of AlSi12 Powder

Key applications of AlSi12 alloy powder include:

• Additive Manufacturing – Used to fabricate complex metal parts by selective laser melting, direct metal laser sintering, binder jetting etc.
• Powder Metallurgy – Compacting and sintering to create high performance parts like piston rings, pump components, rocker arms.
• Metal Injection Molding – Produces intricate components with excellent properties and surface finish.
• Wear Resistant Coatings – Applied via thermal spray methods on cylinder bores, piston skirts, engine blocks.
• Brazing Filler – For joining aluminum and steel components in automotive, aerospace applications.
• Friction Materials – High silicon content improves friction performance. Used in brake pads, clutch discs.
• Casting – Added to aluminum melts to improve castability and wear resistance.

Specifications of AlSi12 Powder

AlSi12 powder is available in different size ranges, grades and purity levels:

• Particle Size: From 10 – 150 microns for AM, under 45 microns for MIM feedstock.
• Morphology: Spherical, irregular and mixed shapes. Spherical improves flow and packing.
• Purity: From commercial to high purity grades based on elemental analysis.
• Oxygen Content: Levels range from 300 – 1000 ppm for gas atomized, higher for water atomized.
• Grades: Customized composition and powder characteristics based on application.
• Surface Area: For nanoscale powder surface area reaches up to 10 m2/g.

Global AlSi12 Powder Suppliers

Some of the major AlSi12 powder suppliers globally are:

• Alpoco (UK)
• AMC Powders (Germany)
• Makin Metal Powders (UK)
• Belmont Metals (US)
• CNPC Powder (China)
• SCM Metal Products (US)
• Hoganas (Sweden)

These companies offer various particle size distributions, powder morphology, bespoke AlSi12 powder grades tailored for additive manufacturing, thermal spray, MIM, and other uses.

AlSi12 Powder Pricing

AlSi12 powder prices depend on:

• Purity levels
• Particle shape and size range
• Order quantity
• Additional powder processing
• Supplier and location

In general, spherical gas atomized powder with controlled particle size distribution and high purity for AM and MIM costs significantly higher than commercial grades.

Handling and Storage of AlSi12 Powder

AlSi12 powder should be stored and handled carefully to avoid:

• Contact with moisture – leads to oxidation. Store in sealed containers with desiccant bags.
• Agglomeration – prevents flow. Store cool, dry powder and consider addition of flow agents.
• Fire hazards – do not store near ignition sources due to flammability of finely divided metals.
• Inhalation – use masks to prevent inhaling fine powders during handling.
• Safety data sheet precautions from supplier should be followed.

Proper inert gas glove box techniques recommended when handling reactive aluminum powders.

Testing and Characterization Methods

Key test methods for AlSi12 powder include:

• Chemical analysis – ICP and XRF techniques determine composition, purity levels.
• Particle size analysis – Carried out as per ASTM B822 using laser diffraction.
• Morphology – Scanning electron microscopy reveals shape, surface structure.
• Powder flow – Measured by Hall flowmeter as per ASTM B213 standard.
• Density – Measured by gas pycnometry or apparent density method.
• Microstructure – X-ray diffraction analysis for phases present.

Thorough testing and inspection ensures AlSi12 powder meets application requirements.

Comparison of AlSi12 and AlSi10Mg Powders

AlSi12 and AlSi10Mg are two aluminum alloy powders compared:

AlSi12 provides the best combination of wear properties, machinability and low cost whereas AlSi10Mg offers higher strength and corrosion resistance required for critical structural parts.

AlSi12 Powder FAQs

Q: How is AlSi12 powder produced?

A: AlSi12 powder is commercially produced by gas atomization and water atomization of the molten alloy. Mechanical milling is also used to make this powder.

Q: What is AlSi12 powder used for?

A: AlSi12 finds use in additive manufacturing, powder metallurgy parts production, thermal spray coatings, metal injection molding, and other applications needing a lightweight alloy with good wear properties and machinability.

Q: What is the typical particle size for AlSi12 powder in AM?

A: For most binder jet and powder bed fusion AM processes, the ideal particle size range for AlSi12 powder is 20-65 microns with good powder flow characteristics.

Q: Does AlSi12 powder require special handling precautions?

A: Yes, it is recommended to handle aluminum powders under inert conditions and avoid accumulation of fine powder to minimize fire and explosion hazards. Proper ventilation and PPE should be used.

Q: Where can I purchase AlSi12 powder for making wear-resistant coatings?

A: Specialty AlSi12 grades suitable for thermal spray coatings can be purchased from leading suppliers like Makin Metal Powders, Alpoco, Belmont Metals, and Hoganas.