Exploring Cast Aluminum Alloy: Characteristics, Properties, and Applications

1. Alloy Classification and Codes

Alloy codes are composed of the Chinese pinyin letters “ZL” that represent cast aluminum, followed by three Arabic numerals.

The first numeral after “ZL” denotes the alloy series, with 1, 2, 3, and 4 respectively standing for aluminum-silicon, aluminum-copper, aluminum-magnesium, and aluminum-zinc alloy series.

The second and third numerals after “ZL” denote the sequence number of the alloy.

High-quality alloys are denoted with an “A” after their code.

Alloy Types	Al-Si System	Al-Cu System	Al-Mg System	Al-Zn System
Alloy Designations	ZL1XX	ZL2XX	ZL3XX	ZL4XX

2. Alloy Casting Methods and Modification Treatment Codes

Code	Title	Code	Title
S	Sand Casting	K	Shell Molding Casting
J	Die Casting	Y	Pressure Die Casting
R	Investment Casting	B	Heat Treatment

3. Characteristics, Types, and Heat Treatment Status of Triple Alloy

Heat Treatment Condition Code	Heat Treatment Condition Categories	Characteristics
F	As-cast Condition	——
T1	Artificial Aging	For wet sand molds, metal molds, and particularly die-cast parts, partial solid solution effects are noticed due to the rapid cooling speed. Aging treatment can increase strength and hardness, and improve machinability.
T2	Annealing	Eliminate the stress generated in the casting process to enhance dimensional stability and improve the plasticity of the alloy.
T4	Solution Heat Treatment with Natural Aging	By implementing solution strengthening through heating, insulation, and rapid cooling, we can enhance the mechanical properties of alloys, particularly improving the alloy’s ductility and its corrosion resistance at room temperature conditions.
T5	Solution Heat Treatment with Partial Artificial Aging	Following solution treatment, an incomplete artificial aging process is carried out, which is conducted at lower temperatures or over shorter durations. The aim is to further enhance the strength and hardness of the alloy.
T6	Solution Heat Treatment with Complete Artificial Aging	The highest tensile strength can be achieved, though at the expense of reduced ductility. Aging is carried out at elevated temperatures or over an extended period of time.
T7	Solution Heat Treatment with Stabilization Treatment	Enhancing the structural and dimensional stability of castings, as well as the corrosion resistance of the alloy. Primarily used for components operating at elevated temperatures, the stabilization treatment temperature can approach the working temperature of the casting.
T8	Solution Heat Treatment with Softening Treatment	After solution treatment, casting parts with high plasticity and excellent dimensional stability are obtained by utilizing temperatures above stabilization treatment.
T9	Cold and Hot Cycle Treatment	Fully eliminate internal stress in castings and stabilize dimensions. Used for high-precision castings.

4. Types of Cast Aluminum Alloy

ZL101

ZL101 is known for its simple composition, easy melting and casting, good casting performance, good air tightness, and relatively good welding and cutting processing performance, but its mechanical properties are not high.

It is suitable for casting various parts with thin walls, large areas, complex shapes, and low strength requirements, such as pump housings, gearboxes, instrument shells (frames), and parts on household appliances. It is mainly produced by sand casting and metal casting.

Zl101A

The addition of a small amount of Ti to ZL101 refines the grain and strengthens the alloy’s structure, resulting in comprehensive properties that are higher than those of ZL101 and ZL102, as well as good corrosion resistance.

It can be used as high-quality castings for general load-bearing structural components in engineering, as well as various structural components on motorcycles, automobiles, household appliances, and instrument products. Its usage is currently second only to ZL102. Sand casting and metal casting are commonly used for production.

Zl102

This alloy’s main characteristic is good fluidity, with other properties similar to ZL101, but with better air tightness than ZL101.

It can be used to cast various complex-shaped thin-walled die-castings and low-strength thin-walled, large-area, and complex-shaped metal or sand-cast parts. Whether it is a die-casting or a metal/sand casting, it is the most commonly used aluminum alloy in civilian products.

Zl104

Due to its large number of working crystals and the addition of Mn, which counteracts the harmful effects of Fe mixed into the material, this alloy has good casting performance, excellent air tightness, corrosion resistance, and relatively good welding and cutting processing performance.

However, its heat resistance is poor.

It is suitable for producing complex-shaped, large-sized dynamic structural parts with large loads, such as turbocharger housings, cylinder heads, cylinder liners, and other parts. It is mainly produced by die-casting, but sand casting and metal casting are also commonly used.

Zl105, ZL105A

Due to the addition of Cu and a reduction in Si content, this alloy’s casting and welding performance are worse than ZL104, but its room temperature and high-temperature strength and cutting processing performance are better than ZL104, with slightly lower plasticity and poorer corrosion resistance.

It is suitable for use as complex-shaped, large-sized, and heavily loaded dynamic structural components such as turbocharger housings, cylinder heads, cylinder liners, and other parts.

ZL105A reduces the impurity element Fe content of ZL105 and increases the alloy’s strength, resulting in better mechanical properties than ZL105. High-quality castings are commonly used for production.

ZL106

The addition of a small amount of Ti and Mn, as well as an increase in Si content, improves the casting and high-temperature performance of this alloy, making it better than ZL105 in terms of air tightness and corrosion resistance.

It can be used as structural components for general loads and parts that require good air tightness and work at higher temperatures. Sand casting and metal casting are mainly used for production.

ZL107

ZL107 has excellent casting and air tightness performance, good mechanical properties, average welding and cutting processing performance, and slightly poorer corrosion resistance.

It is suitable for producing structural components that withstand general dynamic or static loads and parts that require air tightness. Sand casting is commonly used for production.

ZL108

Due to its high Si content and the addition of Mg, Cu, and Mn, ZL108 has excellent casting performance, a small coefficient of thermal expansion, good wear resistance, high strength, and good heat resistance. However, it has slightly lower corrosion resistance.

It is suitable for producing pistons for internal combustion engines and other parts that require wear resistance, as well as parts that require stable dimensions and volume. It is mainly produced by die-casting and metal casting, but sand casting can also be used.

ZL109

This is a complex alloy of Al-Si-Cu-Mg-Ni, with an increased Si content and the addition of Ni to provide excellent casting and air tightness performance, as well as high-temperature strength, improved wear resistance, and corrosion resistance. The linear expansion coefficient and density are also significantly reduced.

It is suitable for producing pistons for internal combustion engines and parts that require wear resistance and stable dimensions and volume. Metal casting and sand casting are mainly used for production.

ZL111

ZL111 is a complex alloy with the addition of Mn and Ti, providing excellent casting performance, good corrosion resistance, air tightness, and high strength. Its welding and cutting processing performance is average.

It is suitable for casting complex-shaped, heavily loaded dynamic structural components (such as aircraft engine components, water pumps, oil pumps, impellers, etc.) and parts that require good air tightness and work at higher temperatures. Metal casting and sand casting are mainly used for production, but die-casting can also be used.

ZL114A

ZL114A is a complex alloy with the addition of Mn and Ti, providing excellent casting performance, good corrosion resistance, air tightness, and high strength. Its welding and cutting processing performance is average.

ZL115

ZL115 has good casting performance and high mechanical properties, mainly used as heavy-duty engineering structural components and other parts such as valve housings and impellers. Sand casting and metal casting are mainly used for production.

ZL116

ZL116 is a complex alloy of Al-Cu-Mg with the removal of Zn and Sb from ZL115 and the addition of trace elements Ti and Be. The alloy’s grain is refined, and the harmful effects of Fe impurities are reduced, providing good casting and air tightness performance as well as high mechanical properties.

It is suitable for casting dynamic structural components that withstand large loads, such as parts on aircraft and missiles, and various parts with good comprehensive properties in civilian products. Sand casting and metal casting are mainly used for production.

ZL117

ZL117 is a complex alloy of Al-Cu-Mg with a hypereutectic structure and a high Si content of 19-22%, with the addition of trace element Mn and rare earth element RE. It has excellent casting performance, good room temperature and high-temperature strength, low coefficient of thermal expansion, and is a high-level wear-resistant material consisting of many hard primary Si particles distributed on a soft matrix.

It is suitable for casting pistons for internal combustion engines, brake pads, and other wear-resistant parts with stable dimensions and volume, as well as high-strength structural components. Metal casting is mainly used for production, but sand casting can also be used.

In addition, the Aviation Industry Corporation of China has also developed three aluminum-silicon alloys (ZL112Y, ZL113Y, and ZL117Y). ZL112Y and ZL113Y are Al-Si-Cu die-casting alloys, both with good casting performance, air tightness, and high mechanical properties, suitable for casting parts that require high strength and working temperatures and good air tightness, as well as other wear-resistant parts such as pistons with stable dimensions, volume, and good heat transfer performance.

Die-casting is mainly used for production, but sand casting and metal casting can also be used. Unlike ZL108, the Si content is reduced, and the Cu content that enhances solid solution strengthening and precipitation hardening is increased, resulting in better room temperature and high-temperature performance than ZL108.

ZL201

ZL201 has good room temperature and high-temperature mechanical properties, moderate plasticity, average welding and cutting processing performance, poor fluidity with a tendency towards hot cracking, and poor corrosion resistance.

It is suitable for casting structural components that work at relatively high temperatures (200-300℃) or parts that bear large dynamic or static loads at room temperature, as well as parts that work at low temperatures (-70℃). Sand casting is mainly used for production.

ZL201A

ZL201A greatly reduces the content of impurities Fe and Si compared to ZL201, resulting in higher room temperature and high-temperature mechanical properties. It has good cutting and welding performance but poor casting performance.

It can be used for parts that work at 300℃ or bear large dynamic or static loads at room temperature. Sand casting is mainly used for production.

ZL202

ZL202 has relatively good casting performance and high-temperature strength, hardness, and wear resistance, but poor corrosion resistance.

It is suitable for casting parts that work at a temperature of 250℃ and bear small loads, such as cylinder heads. Sand casting and metal casting are mainly used for production.

ZL203

ZL203 has a lower Si content which results in slightly poorer fluidity, greater tendency toward hot cracking, and poorer corrosion resistance. However, it has good high-temperature strength, welding, and cutting processing performance.

It is suitable for casting parts that work at a temperature below 250℃ and bear small loads or parts that bear large loads at room temperature, such as instrument parts and crankcase bodies. Sand casting and low-pressure casting are mainly used for production.

ZL204A

ZL204A is a high-purity, high-strength cast Al-Cu alloy, with good plasticity and welding and cutting processing performance, but poor casting performance.

It is suitable for casting structural components that bear large loads, such as support bases and support arms. Sand casting and low-pressure casting are mainly used for production.

ZL205A

ZL205A is currently the strongest aluminum alloy in use in the world. It has good plasticity and corrosion resistance, excellent cutting and welding performance, but poor casting performance.

It is suitable for casting structural components that bear large loads and some parts with low airtightness requirements. Sand casting, low-pressure casting, and metal casting can be used.

ZL207

ZL207 has very high high-temperature strength with average casting performance, welding and cutting processing performance, and low room temperature strength.

It is suitable for casting various structural components that work under 400℃, such as valve shells on aircraft engines and some heat-resistant components in the petroleum industry. Sand casting and low-pressure casting are mainly used for production.

ZL209

ZL209 has higher tensile strength, yield point, and high-temperature strength than ZL201A with good welding and cutting processing performance, but poor casting performance and elongation.

It is suitable for casting various wear-resistant components that work at higher temperatures, such as parts on internal combustion engines. Sand casting is mainly used for production.

ZL301

ZL301 is the most corrosion-resistant aluminum alloy currently available with good cutting processing performance, relatively good welding performance, high strength, good anodizing performance, but complex casting process, cumbersome operation, and easy to produce defects such as looseness and hot cracking.

It is suitable for casting various parts with large loads in corrosive media such as seawater working at a temperature of 150℃, such as various components in marine vessels, pump housings, impellers, frames in the petroleum industry. Sand casting is mainly used for production.

ZL303

ZL303 has better high-temperature strength than ZL301, good corrosion resistance (slightly worse than ZL301), excellent cutting processing performance, good welding performance, better casting performance than ZL301, cannot be heat-treated, resulting in much lower mechanical properties than ZL301.

It is suitable for casting parts such as aircraft engines, missiles, internal combustion engines, chemical pumps, oil pumps, petrochemical gas pump housings, rotors, blades that bear medium loads in corrosive media such as seawater, chemical industry, and gas. Pressure casting and sand casting are mainly used.

ZL305

ZL305 has better casting performance and more stable tissue after natural aging than ZL301 and ZL303 due to the addition of Zn and the reduction of Mg content. The tendency to form looseness and hot cracking is small because of the addition of trace elements Ti and Be, resulting in good comprehensive properties and strong stress corrosion resistance.

However, its mechanical properties at high temperatures are poor. It is suitable for casting parts that bear large loads and work in corrosive media such as seawater, chemicals, and gas below 100℃, such as aircraft, internal combustion engines, chemical pumps, oil pumps, petrochemical gas pump housings, rotors, blades. Sand casting is mainly used for production.

ZL401

ZL401 has excellent casting performance, a small tendency towards shrinkage and hot cracking, high mechanical properties, good welding and cutting processing performance, but high specific gravity, low plasticity, and poor corrosion resistance.

It is mainly used for pressure casting and casting molds, templates, and structural components on aircraft, internal combustion engines, vehicles, and other products that work at temperatures not exceeding 200℃ and bear medium loads. Pressure casting, sand casting, and metal casting can be used.

5. Chemical Composition of Aluminum Alloys for Die Casting

Alloy Series	Country	Alloy Grade	WB/%					Standard Specifications
Alloy Series	Country	Alloy Grade	Si	Cu	Mg	Fe	Al	Standard Specifications
AI-Si series	China	YL102	10.0-13.0	<0.6	<0.05	<1.2	Allowance	GB/T15115-94
	Japan	ADC1	11.0-13.0	<1.0	<0.30	<1.2		JISH5302-82
	America	413	11.0-13.0	<1.0	<0.35	<2.0		ASTMB85-82
	Russia	AJ12	10.0-13.0	<0.6	<0.10	<1.5		TOCT2685-82
	Germany	AlSil2	11.0-13.5	<0.10	<0.05	<1.0		DIN1725
AI-Si-Mg series	China	YL104	8.0-10.5	<0.30	0.17-0.30	<1.0	Allowance	GB/T15115-94
	Japan	ADC3	9.0-10.0	<0.60	0.40-0.60	<1.3		JISH5302-82
	America	360	9.0-10.0	<0.60	0.40-0.60	<2.0		ASTMB85-82
	Russia	AJl4	8.0-10.5	<0.10	0.17-0.30	<1.0		TOCT2685-82
	Germany	AlSil0Mg	9.0-11.0	<0.10	0.20-0.50	<1.0		DIN1725
AI-Si-Cuseries	China	YL112	7.5-9.5	3.0-4.0	<0.30	<1.2	Allowance	GB/T15115-94
	China	YL113	9.6-12.0	1.5-3.5	<0.30	<1.2		GB/T15115-94
	Japan	ADC10	7.5-9.5	2.0-4.0	<0.30	<1.3		JISH5302-82
	Japan	ADC12	9.6-12.0	1.5-3.5	<0.30	<1.3		JISH5302-82
	America	380	7.5-9.5	3.0-4.0	<0.10	<1.3		ASTMB85-82
	America	383	9.5-11.5	2.0-3.0	<0.10	<1.3		ASTMB85-82
	Russia	AJl6	4.5-6.0	2.0-3.0	<0.10	<1.5		TOCT2685-82
	Germany	AlSi8Cu3	7.5-9.5	2.0-3.5	<0.30	<1.3		DIN1725
AI-Mg series	China	YL302	0.80-1.30	<0.10	4.5-5.5	<1.2	Allowance	GB/T15115-94
	Japan	ADC5	<0.30	<0.20	4.0-8.5	<1.8		JISH5302-82
	America	518	<0.35	<0.25	7.5-8.5	<1.8		ASTMB85-82
	Russia	AlMg9	<0.50	<0.05	7.0-10.0	<1.0		DIN1725

6. Mechanical Properties of Aluminum-Silicon Series Casting Alloys Table

(GB/T 1173-2013)

Alloy Grade	Alloy Code	Casting Method	Alloy Condition	Tensile Strength Rm/MPa	Elongation Ratio A/%	Brinell Hardness HBW.
Alloy Grade	Alloy Code	Casting Method	Alloy Condition	≥
ZAlSi7Mg	ZLl01	S、R、J、K	F	155	2	50
		S、R、J、K	T2	135	2	45
		JB	T4	185	4	50
		S、R、K	T4	175	4	50
		J、JB	T5	205	2	60
		S、R、K	T5	195	2	60
		SB、RB、KB	T5	195	2	60
		SB、RB、KB	T6	225	1	70
		SB、RB、KB	T7	195	2	60
		SB、RB、KB	T8	155	3	55
ZAlSi7MgA	ZL101A	S、R、K	T4	195	5	60
		J、JB	T4	225	5	60
		S、R、K	T5	235	4	70
		SB、RB、KB	T5	235	4	70
		JB、J	T5	265	4
		SB、RB、KB	T6	275	2	80
		JB、J	T6	295	3	80
ZAlSi12	ZL102	SB、JB、RB、KB	F	145	4	50
		J	F	155	2	50
		SB、JB、RB、KB	T2	135	4	50
		J	T2	145	3	50
ZAlSi9Mg	ZL104	S、R、J、K	F	150	2	50
		J	T1	200		65
		SB、RB、KB	T1	230	2	70
		J、JB	T6	240	2	70
ZAlSi5Cu1Mg	ZL105	S、J、R、K	T1	155		65
		S、R、K	T5	215	1	70
		J	T5	235		70
		S、R、K	T6	225		70
		S、J、R、K	T7	175	1	65
ZAlSi5Cu1MgA	ZL105A	SB、R、K	T5	275	1	80
ZAlSi5Cu1MgA	ZL105A	J、JB	T5	295	2	80

7. Other Series’ Cast Aluminum Alloy Mechanical Properties Table