{"id":7809,"date":"2026-09-23T04:27:18","date_gmt":"2026-09-23T04:27:18","guid":{"rendered":"https:\/\/chinametalfoundry.com\/?p=7809"},"modified":"2026-09-23T04:27:18","modified_gmt":"2026-09-23T04:27:18","slug":"aluminum-casting-alloys-a356-vs-a380","status":"publish","type":"post","link":"https:\/\/chinametalfoundry.com\/es\/blog\/aluminum-casting-alloys-a356-vs-a380\/","title":{"rendered":"Aleaciones de aluminio para fundici\u00f3n: comparaci\u00f3n entre A356, A380 y ADC12"},"content":{"rendered":"
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Most RFQs we receive specify “aluminum” and stop there. That single word covers alloys whose tensile strength differs by 80 MPa, whose thermal conductivity differs by 60%, and where one can be welded on site while another cracks under the torch. Choosing between aluminum casting alloys is not a paperwork step \u2014 it decides tooling life, leak-test yield, and whether the part survives five years outdoors.<\/p>\n<\/div>\n

Among the hundreds of registered aluminum casting alloys, three grades cover the majority of industrial cast aluminum parts \u2014 A356.0, A380.0 and ADC12<\/strong> \u2014 using composition limits, mechanical property ranges, and the process each alloy is actually designed for. Where numbers matter, we show the calculation rather than a rule of thumb. Composition limits follow the Aluminum Association designation system; process practice references AFS<\/a> y The Aluminum Association<\/a> publications.<\/p>\n

\"aluminum
Sample plates in three common aluminum casting alloys \u2014 surface appearance already hints at silicon content and casting process.<\/figcaption><\/figure>\n

How Aluminum Casting Alloys Are Named (and Why It Matters)<\/h2>\n

Every buyer should be able to read a grade and predict its behaviour. The designation is not marketing; it encodes chemistry.<\/p>\n

The Aluminum Association system<\/h3>\n
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Cast grades use three digits plus a decimal: xxx.0<\/strong>, where the “.0” marks a casting alloy (wrought grades use four digits with no decimal). The first digit names the main alloying family: 2xx.x = copper, 3xx.x = silicon plus copper and\/or magnesium, 4xx.x = silicon only, 5xx.x = magnesium, 7xx.x = zinc. Nearly all commercial aluminum casting alloys you will actually be quoted are 3xx.x, because silicon is what makes molten aluminum flow.<\/p>\n

A leading “A”<\/strong> means a premium-purity variant with tightened impurity limits. The clearest example: 356.0 allows iron up to 0.6%, while A356.0<\/strong> caps iron at 0.20%. That single difference is why A356.0 responds to T6 heat treatment with real ductility and 356.0 does not reach the same elongation.<\/p>\n

JIS, EN and the ADC grades<\/h3>\n
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Asian supply chains quote ADC12<\/strong> (JIS H 5302) instead of an AA number; European drawings use EN 1706 grades such as EN AC-43000 or EN AC-46000. These are parallel naming systems for overlapping chemistries, not exotic materials \u2014 buyers sourcing aluminum casting alloys across regions routinely meet the same melt under three different labels. ADC12 sits close to AA 383.0, and EN AC-43000 is the European twin of A356.0’s lower-silicon cousin. When a supplier quotes ADC12 and your drawing says A380.0, you are usually looking at two acceptable answers to the same requirement \u2014 not a substitution to reject automatically.<\/p>\n

Composition: The Five Elements That Decide Everything<\/h2>\n

The table below lists the composition windows for the aluminum casting alloys buyers get quoted most. Everything downstream \u2014 fluidity, heat treatment response, machinability, corrosion \u2014 follows from these columns.<\/p>\n\n\n\n\n\n\n\n\n\n
Aleaci\u00f3n<\/th>\nSi %<\/th>\nCu %<\/th>\nMg %<\/th>\nFe max %<\/th>\nZn max %<\/th>\n<\/tr>\n<\/thead>\n
A356.0<\/strong><\/td>\n6.5 \u2013 7.5<\/td>\n0.20 max<\/td>\n0.25 \u2013 0.45<\/td>\n0.20<\/td>\n0.10<\/td>\n<\/tr>\n
A380.0<\/strong><\/td>\n7.5 \u2013 9.5<\/td>\n3.0 \u2013 4.0<\/td>\n0.10 max<\/td>\n1.3<\/td>\n3.0<\/td>\n<\/tr>\n
ADC12<\/strong><\/td>\n9.6 \u2013 12.0<\/td>\n1.5 \u2013 3.5<\/td>\n0.30 max<\/td>\n1.3<\/td>\n1.0<\/td>\n<\/tr>\n
319.0<\/strong><\/td>\n5.5 \u2013 6.5<\/td>\n3.0 \u2013 4.0<\/td>\n0.10 max<\/td>\n1.0<\/td>\n1.0<\/td>\n<\/tr>\n
383.0<\/strong><\/td>\n9.5 \u2013 11.5<\/td>\n2.0 \u2013 3.0<\/td>\n0.10 max<\/td>\n1.3<\/td>\n3.0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Silicon Runs the Casting: A Lever-Rule Calculation<\/h2>\n

Silicon is the element that makes aluminum casting alloys castable at all: pure aluminum has a wide freezing range and hot-tears in the mould. Aluminum and silicon form a eutectic at 12.6% Si and 577 \u00b0C<\/strong>. Everything below that composition freezes as primary aluminum dendrites first, then eutectic. The proportion is not a mystery \u2014 you can estimate it with the lever rule, taking silicon solubility in the solid phase at the eutectic temperature as about 1.65%:<\/p>\n

Eutectic fraction \u2248 (12.6 \u2212 Sialloy<\/sub>) \u00f7 (12.6 \u2212 1.65) subtracted from one. For A356.0 at 7.0% Si:<\/p>\n