AlMg5Si (common grades such as EN AC-51400 or AlMg5Si1 ) It is a typical aluminum-magnesium-silicon casting alloy with excellent corrosion resistance, medium strength and good weldability , and is widely used in many industrial fields.

1. Main application areas and typical parts of AlMg5Si castings :

1. Shipbuilding and marine engineering

• Hull structural parts (hatch covers, handrails, trusses, etc.)
• Deck equipment (bases, housings, connections)
• Offshore platform structures

Reason: Excellent seawater corrosion resistance, suitable for humid or salt spray environment.

2. Transportation (especially rail and commercial vehicles)

• Railway vehicle body structure
• Automobile chassis components (subframes, wheels, brackets)
• Trailer structural parts

 Reason: Higher strength-to-weight ratio and impact resistance.

3. Energy and power equipment

• Wind turbine cabin structural parts
• High voltage switch housing, electrical connectors

 Reason: Certain strength, conductivity and corrosion resistance are required.

4. Building and structural parts

• Curtain wall connection components
• Aluminum formwork support system

5. Mechanical equipment

• Pump body, housing
• Industrial automation equipment parts

2. Characteristics and key points of AlMg5Si casting process

Compared with other cast aluminum alloys (such as AlSi7Mg , AlSi10Mg , AlCu4Ti , etc.), AlMg5Si has the following characteristics and points for attention during melting , pouring and solidification :

1. The oxide film is highly sensitive and requires a good protective atmosphere

• The magnesium content is high and it is easily oxidized during the smelting process to form MgO .
• Recommended use Inert gas protection (such as Ar ) or flux protection , especially during smelting and sub-packaging.

2. Strong air absorption, easy to produce pinholes

• Mg reacts with hydrogen to increase the tendency to getter, thus:
  • Refining degassing (such as rotor degassing, Ar /Cl composite gas) must be sufficient ;
  • Melt processing should be carried out at low temperatures ( 690–720°C is recommended ) to avoid excessive temperatures that promote aspiration.

3.High requirements for the mold (mold)

• The tendency of thermal cracking is relatively large, and the mold design should consider:
  • Reasonable cooling system distribution
  • Avoid combining thick sections with fast shrinking areas

4. The cooling rate needs to be controlled during the crystallization process

• AlMg5Si alloy has a wide solidification range (about 30–40°C ) and shrinkage should be avoided:
  • Reasonable setting of gate system and riser
  • Sequential solidification control or pressure consolidation techniques can be used when necessary

5. Post-processing heat treatment methods are limited

• T6 heat treatment (such as quenching + aging) is usually not possible because its strengthening mechanism mainly relies on solid solution rather than precipitation hardening;
• Generally adopted Use in T5 or natural aging ( F ) state .

Summary of key comparisons :

Process	AlMg5Si Features	Differences from other aluminum alloys (such as AlSi10Mg )
Melting protection	Easy to oxidize, absorb	High magnesium content → more inert gas protection is needed
Degassing treatment	Hydrogen removal refining is required	Stronger than normal air intake AlSi Tie
Casting system	Sequential solidification design required	Easy to shrink and uneven cooling has a great impact
Heat Treatment	T6 is usually not performed	Not suitable for precipitation hardening

The following are The recommended parameters of AlMg5Si casting process are suitable for process scenarios dominated by gravity casting (sand mold, metal mold). It is also suitable for low-pressure casting, such as when higher density is required for the production of structural parts.

1. Melting and insulation

project	Recommended parameters	illustrate
Melting temperature	700–740 °C	Avoid excessive temperatures to reduce oxidation and aspiration
Insulation temperature	690–710 °C	Long-term heat preservation requires protective atmosphere or flux
Protection method	Argon, nitrogen or flux ( NaCl+KCl )	Prevent magnesium oxidation
Degassing treatment	Ar+ Cl₂ Or degas the rotor for 10–20 minutes	Control hydrogen content ≤0.15 ml/100g Al
Flux Recommendation	Special magnesium aluminum alloy flux, such as Foseco MTS 158	Anti-oxidation, anti-inclusion

2. Pouring

project	Recommended parameters	illustrate
Pouring temperature	710–730 °C (sand mold)  690–710 °C (Metal Type)	Fine-tune according to mold material and wall thickness
Mold preheating temperature (metal mold)	250–300 °C	Prevent cold shut and poor filling
Gate design	Bottom injection, flow rate control, sequential solidification	Reduce oxidation slag and shrinkage
Riser / Feeding System	It is necessary to set up a heat preservation cap or pressurized shrinkage compensation	The alloy has a wide solidification range and large shrinkage
Cooling control	Local chilling iron assisted solidification control	Prevent thermal cracking and shrinkage

3. Heat treatment recommendations

Heat treatment status	Recommended parameters	illustrate
T5 (artificial aging after casting)	160–180 °C × 5–8 hours	Improved stability, slightly increased strength
F (Not heat treated )	–	Supplied in normal condition, maintain ductility
T6 heat treatment is not recommended	Easy to deform, no obvious reinforcement	Because its strengthening mechanism does not rely on precipitation phase

4. Reference values of cast properties (for comparison only)

Performance Indicators	Numerical range	condition
Tensile strength (Rm)	180–250 MPa	Cast or T5
Yield strength (Rp0.2)	90–160 MPa
Elongation (%)	5–12%
hardness	HB 50–80
density	2.64–2.66 g/cm³

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5. Precautions & Process Optimization Suggestions

• Do not use iron tools to stir for a long time : high-magnesium aluminum alloys are prone to inclusion reactions;
• The pouring system must be designed with an anti-eddy current structure to avoid inclusion of oxide film;
• The mold or cavity should be kept dry to prevent explosion or holes;
• Local reinforcement areas can be assisted by chill iron / pressurization to improve density .

against AlMg5Si is used for fire protection system parts (such as joints, flanges, housings, connectors, etc.) The riser size design suggestions and filling simulation scheme can be divided into two parts:

1. Riser design suggestions (mainly for gravity casting)

Fire protection system parts usually require No leakage, no shrinkage, high density , so the riser design must consider the following points:

1. Riser design principles

project	Recommendations
Riser position	Place in the last solidification area of the part (usually at the top of a thick section)
Riser shape	Cylindrical or oval (easy to process)
Insulation treatment	Insulation riser sleeve + insulation covering agent
Feeding efficiency requirements	≥30% and has a sequential solidification path
Is the riser open?	Generally use open risers unless the pressure difference is well controlled

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2. Riser size estimation method (based on Chvorinov’s law)

use Modulus​​ Method ) Design riser :

• Modulus M ( Modulus ) = V / A
  • V = volume ( cm³ )
  • A = heat dissipation area in contact with air or die ( cm² )

Recommended size relationship:

Notice : The riser should use an insulating sleeve (such as an Exothermic sleeve ) to increase the effective shrinkage compensation volume by 30–50% .

3. Riser neck connection design

Parts module M ( cm )	Riser modulus (need to be ≥ 1.2×M )	Typical riser diameter × height ( mm )
M = 1.0	≥1.2	Ø30 × 35
M = 1.5	≥1.8	Ø45 × 50
M = 2.0	≥2.4	Ø55 × 60
M = 2.5	≥3.0	Ø65 × 70

• The riser neck (the part connecting the riser to the casting) needs to be controlled to solidify slowly , with a modulus slightly lower than the riser but higher than the thickness of the casting.
• Recommendation: Neck diameter = 1.2-1.5 times the wall thickness of the part , and the length should be controlled between 20-40mm to facilitate cutting.

2. Filling and solidification simulation scheme (simulation ideas)

It is recommended to use MAGMASOFT® or ProCAST ® For numerical simulation, the following are the simulation parameters for typical medium – sized flange joints (wall thickness 10-15mm ) in fire protection systems :

1. Simulation target

• Confirm whether the solidification path is sequential
• there porosity ?
• Whether inclusions are generated ( Oxide Trap )
• Is it cold shut or insufficient filling?

2. Simulation setup recommendations

Parameters	Setting suggestions
Alloy Model	AlMg5Si (user defined or input data via thermal analysis)
Wall Thickness Area Mesh	≤1.5 mm grid accuracy
Pouring temperature	710 °C (metal type) or 730 °C (Sand mold)
Mold temperature	250 °C starting
Gate speed	0.3–0.8 m/ s (to prevent air entrainment )
Cooling method	Local chilling (set temperature boundaries to 50–80°C )
Riser heat balance setting	Enable the insulation sleeve data parameters to simulate the delayed solidification effect of the riser

3. Output analysis key diagram:

• Solidification Time distribution diagram → Determine the solidification order
• Porosity Map → Check whether the shrinkage compensation is successful
• Velocity Field diagram → Analyze the filling path
• Oxide Formation → Determine whether to switch to the bottom injection channel system

Conclusion Recommendation

• For fire protection flange parts, using Ø50×60mm insulation riser + symmetrical arrangement of chillers can effectively compensate for shrinkage;
• For large size connectors or housings, it is recommended to use Top injection + double riser system , with internal riser if necessary;
• 2-3 times of scheme comparison and optimization in the early stage of development (different gate / riser combinations can be set);
• If the casting is large and the thickness varies greatly, consider using Low pressure casting + local cooling channels optimize density.

Microarc Oxidation（ MAO) VS Anodic oxidation

Microarc Oxidation（ MAO), It is also been called Plasma electrolytic oxidation(PEO) or  Microplasma oxidation(MPO ).It is a high technology of in-situ growing ceramic layer on the surface of aluminum, magnesium, titanium and other metals and their alloys .

The characteristics of micro-arc oxidation

•(1) The appearance of the ceramic membrane layer is uniformly dense and the combination is firm. It is matte and the color is consistent. The thickness of the film can be controllable from 10UM to 300UM; 

•(2) Good wear resistance; The Hardness is HVA400 to 2500, the highest to 3000HV; The wear resistance is improved to 30% than the original material. 

•(3) Good heat resistance. High temperature impact resistance of 2500°C for 20 seconds (the matrix melts and the ceramic layer is intact after 20 seconds) with strong flexibility , even the matrix is bending, The ceramic layer does not crack or fall off during fracture . 

•(4) Strong corrosion resistance. The salt spray test >1000 hours. 

•(5) Good insulation performance, electrical breakdown strength 5KV/mm, electrical .

Microarc Oxidation VS Anodic oxidation

Specification	Microarc Oxidation	Anodic oxidation
Working time（min ）	10-30	30-60
Thickness of film（um ）	10-300	30-60
Hardness（HV）	1500-2500	300-400
Surface Porosity（%）	0-40	>40
Insulativity	good	uninsulation
Solution PH	neutral or alkaline	acidic
Flexibility	Good	Fragile
Uniformity	Uniform  on an internal and external surface.	Relatively uniform
Wear resistance	Good	Poor
Process flow	deoiling – Microarc oxidation – sealing	Alkali etching – pickling – chemical polishing – anodizing – sealing
Working temperature（°C）	10-90	13-26

TCC has experienced with surface treatment on on the Aluminum with high content of Silicon, eg. ADC12 and A380. If you have such requirement , please contact us by email .

12 inch pressure valve material A356

A356 is widely used to cast components like aircraft parts, pump housings, impellers, high velocity blowers and structural castings .

A356 alloy is a class of alloys in the Alcoa Standard series. This series has three alloys: A356.0, A356.1, and A356.2, which are part of the 356 Series. Its composition is shown in Table 1.

Table 1 Comparison of chemical composition between Alcoa 356 series alloy and domestic ZL101 series aluminum alloy Unit: %

-The 356 series is the American standard brand, and the ZL101 series is the Chinese standard brand;

-S-sand casting, P-metal casting;

-The Chinese standard also makes separate provisions on the content of Pb and Sn impurities (the American standard classifies them as other impurities) : Pb<0.05 Sn<0.01(corresponding to ZL101), Pb< 0.03 Sn< 0.01(corresponding to ZL101A);

-356.2 alloy has a maximum Fe content of 0.25%.

It can be seen that the chemical composition design of Al-7Si-Mg series alloys has the following characteristics: no matter the American standard or the Chinese standard, the common feature is the same composition range of Si elements: (SI-6.5/7.5); For magnesium, the Mg required for casting material is 0.25~0.45; In the American standard, the requirement of magnesium element in the ingot is increased by 0.05%, namely 0.30~0.45, mainly considering the burning loss of magnesium element during smelting.

The main difference in the chemical composition of this series lies in the regulation of impurity content. For the American standard, the first letter of the brand indicates its performance grade, so that the user according to different application requirements to determine the brand. The first letter of the letter B is the highest performance, so the requirements for impurities are also the most stringent. Alloys without a first letter have poor performance and are mainly used in common applications. The A356 series is an in-between material. The number at the end of the brand (0,1,2) is the limit of various impurities according to different occasions. A356.0 is the material composition specified for the material of the castings produced; A356.1 and A356.2 are two kinds of components formulated for the production of raw materials for castings, namely ingot, according to different requirements of use.

ZL101 series mainly defines the material of castings, with high requirements for ZL101A; ZL101 is generally required. The Chinese standard does not specify the composition of the raw material used for casting, namely the ingot.

TCC has rich experience in producing cast aluminum to meet your design. If you have any inquiry on custom parts, Please feel free to send us the CAD drawing and let’s discuss!