ZINC DIE CASTING ALLOYS

Overview

XinYiZInc Alloys manufactures the complete range of zinc die casting alloys. ZAMAK alloys were first developed during the 1920's by The New Jersey Zinc Company. The name ZAMAK draws upon the basic metallurgy of the alloy group: Z-Zinc, A-Aluminum, MA-Magnesium, and K-Kopper (e.g., German). In the United States, ZAMAK 3 isthe most commonalloy for hot chamber die casting. With a combination ofsuperior mechanical properties and low melting/manufacturing costs, it fulfills the needs for most die casting applications. Other ZAMAK alloys include ZAMAK 2, ZAMAK 5, and ZAMAK 7. Common to each alloy is a consistent Aluminum content range, however, the alloys differ in specification by varying amounts of copper, magnesium, and nickel - resulting in different mechanical and physical properties.

XinYiZInc Alloys is the China leader in ZA alloy manufacturing and processtechnology. High strength ZA alloys were originally engineered for gravity casting, but now own an increasing percentage of the die casting market. Today, there are three ZA alloys: ZA8, ZA12, ZA27. ZA8 is the only ZA alloy that can be HOT chamber die cast due to the relatively low melting temperature (708-759 F). ZA12 and ZA27 can be COLD chamber die cast at higher melting temperatures (875-1050 F).

XinYiZIncZamak 3 Ingots stacked on alloy feet

The ACuZinc is another zinc die casting alloy-, developed by General Motors Research and Development engineers. At the outset ACuZinc alloys were limited to production of GM-specific XinYiZIncZamak 3 Ingots stacked on alloy feet parts. More recently, however, the GM licensing agreement allows for a broader scope of applications. With the addition of high percentages of copper, ACuZinc alloys were developed to improve the wear resistance and creep propertiesin the zinc alloy family. Today there are two ACuZinc alloys: ACuZinc 5 (5% Copper), and ACuZinc 10 (10% Copper), and are used in a variety of automotive applications. ACuZinc 5 is HOT chamber die cast due to its lower melting temperature, whereas ACuZinc 10 is COLD chamber die cast.

The process of casting these zinc die casting alloys utilize an hydraulic press that allows metal to be injected into a cavity at extremely high pressures. The term "HOT" (asin HOT chamber) refers to the fact the metal pump (gooseneck) is immersed in the hot metal. In COLD chamber die casting, the metal is ladled into a holding sleeve until a plunger forcesthe metal into the cavity. These processes are designed for high volume applications, and are cast at "net-shaped" precision.

For more information about Eastern Alloys and its selection of die-casting alloys, contact the XinYiZInc Alloys sales or send inquiries to judyya.yes@gmail.com.

Alloys Description

Alloy	Description
Zamak 3	Usually the first choice for zinc die casting. Offers an excellent balance of physical and mechanical properties, superb castability, long - term dimensional stability. Over 70% of North American zinc castings are in No. 3. Widely available, good finishing characteristics for plating, painting, and chromate treatments. Considered the “standard” zinc die - casting alloy.
Zamak 5	Marginally stronger and harder than Zamak 3, but with reduced ductility that can affect formability during secondary operations. Contains an addition of 1% copper, which accounts for its property changes. Widely used in Europe, shows excellent castability and improved creep performance over Zamak 3. Material specifiers may choose it over Zamak 3 by design modifications. Readily plated, finished, and machined, comparable to Zamak 3.
Zamak 7	A modification of Zamak 3 with lower magnesium content to increase fluidity. Has lower impurity levels and a small quantity of nickel specified to avoid inter - granular corrosion problems. Slightly better ductility than Zamak 3 with remaining properties at a similar level. Popular for thin - walled components requiring a good surface finish. Die casting parameters like metal and die temperatures are crucial to control for consistent quality.
Zamak 2	The only ZAMAK alloy used for gravity casting, mainly for metal forming dies or plastic injection tools. Sometimes referred to as Kirksite. Offers high strength and hardness within the ZAMAK family. Changes in copper content (3%) result in property changes upon long - term aging, including slight dimensional growth, lower elongation, and reduced impact performance. Has limited die - cast castability but offers interesting characteristics for North American designers, such as good bearing properties and potential to eliminate bushings and wear inserts in die - cast designs.
ZA - 8	A good gravity casting alloy, rapidly growing in pressure die casting. Has improved strength, hardness, and creep properties over ZAMAKs, with the exception of Zamak 2. Readily plated and finished using standard ZAMAK procedures. Recommended when the performance of Zamak 3 and 5 is insufficient, especially in high - strength and creep - property - critical die - casting applications.
ZA - 12	The most versatile zinc alloy in combining high - performance properties and ease of fabrication via gravity or pressure die casting. Best gravity casting alloy for sand, permanent mold, and new graphite mold casting processes. Also a good pressure die - casting alloy (cold chamber), providing a sounder structure than ZA - 27, with higher die - cast elongation and impact properties. For these reasons, die - cast ZA - 12 often competes with ZA - 27 for strength applications. An excellent bearing alloy, also platable, though plating adhesion is reduced compared to ZAMAK alloys.

Mechanical Properties

	Zamak 3	Zamak 5	Zamak 7	Zamak 2	ZA - 8	ZA - 12	ZA - 27
Ultimate Tensile Strength: psi x 10. (MPa)	41 (283)	48 (328)	41 (283)	52 (359)	54 (374)	58 (400)	61 (421)
Yield Strength - 0.2% Offset: psi x 10.(MPa)	32 (221)	39 (269)	32 (221)	41 (283)	42 (290)	46 (317)	55 (379)
Elongation: % in 2"	10	7	13	7	6 - 10	4 - 7	1 - 3
Shear Strength: psi x 10. (MPa)	31 (214)	38 (262)	31 (214)	46 (317)	40 (275)	43 (296)	47 (325)
Hardness: Brinell	82	91	80	100	95 - 110	95 - 115	105 - 125
Impact Strength: ft - lb (J)	43 (58)	48 (65)	43 (58)	35 (48)	31 (42)	21 (29)	9 (5)
Fatigue Strength Rotary Bend - 5x10.cycles: psi x 10. (MPa)	6.9 (48)	8.2 (57)	6.8 (47)	8.5 (59)	15 (103)	17 (117)	21 (145)
Compressive Yield Strength 0.1% Offset: psi x 10. (MPa)	60 (414)	87 (600)	60 (414)	93 (641)	37 (252)	39 (269)	52 (385)
Modulus of Elasticity - psi x	12.4(85.5)	12.4 (85.5)	12.4 (85.5)	12.4 (85.5)	-	-	-
Poisson's Ratio	0.27	0.27	0.27	0.27	0.29	0.30	0.32

Physical Properties

	Zamak 3	Zamak 5	Zamak 7	Zamak 2	ZA - 8	ZA - 12	ZA - 27
Density: lb/cu in (g/cm³)	0.24 (6.6)	0.24 (6.6)	0.24 (6.6)	0.24 (6.6)	0.227 (6.3)	0.218 (6.0)	0.181 (5.0)
Melting Range: °F (°C)	718 - 728 (381 - 387)	717 - 727 (380 - 386)	718 - 728 (381 - 387)	715 - 734 (379 - 390)	707 - 759 (375 - 404)	710 - 810 (377 - 432)	708 - 903 (376 - 484)
Electrical Conductivity: %IACS	27	26	27	25	27.7	28.3	29.7
Thermal Conductivity: BTU/ft/hr/°F (W/m/hr/°C)	65.3 (113.0)	62.9 (108.9)	65.3 (113.0)	60.5 (104.7)	66.3 (114.7)	67.1 (116.1)	72.5 (125.5)
Coefficient of Thermal Expansion: 68 - 212°F μin/in/°F (100 - 200°C μm/mm/°C)	15.2 (27.4)	15.2 (27.4)	15.2 (27.4)	15.4 (27.8)	12.9 (23.3)	13.4 (24.2)	14.4 (26.0)
Specific Heat: BTU/lb/°F (J/kg/°C)	0.10 (419)	0.10 (419)	0.10 (419)	0.10 (419)	0.104 (435)	0.107 (448)	0.125 (534)
Pattern of Die Shrinkage: in/in	0.007	0.007	0.007	0.007	0.007	0.0075	0.008

Compositions

Chemical Specification (per ASTM) (% by Weight) for ZAMAK Alloys
	Zamak 3		Zamak 5		Zamak 7		Zamak 2
	Ingot	Casting	Ingot	Casting	Ingot	Casting	Ingot	Casting
Al	3.9 - 4.3	3.7 - 4.3	3.9 - 4.3	3.7 - 4.3	3.9 - 4.3	3.7 - 4.3	3.9 - 4.3	3.7 - 4.3
Mg	0.03 - 0.06	0.02 - 0.06	0.03 - 0.06	0.02 - 0.06	0.01 - 0.020	0.005 - 0.020	0.025 - 0.05	0.02 - 0.06
Cu	0.10 max	0.1 max	0.7 - 1.1	0.7 - 1.2	0.10 max	0.1 max	2.7 - 3.3	2.6 - 3.3
Fe (max)	0.035	0.05	0.035	0.05	0.035	0.035	0.035	0.05
Pb (max)	0.004	0.005	0.004	0.005	0.003	0.003	0.004	0.005
Cd (max)	0.003	0.004	0.003	0.004	0.002	0.002	0.003	0.004
Sn (max)	0.0015	0.002	0.0015	0.002	0.001	0.001	0.0015	0.002
Ni (other)	-	-	-	-	0.005 - 0.020	0.005 - 0.020	-	-
Zn	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.
Color Code XinYiZinc	Green		Red		None		Red
	Green		Red		None		Red

Chemical Specification (per ASTM) (% by Weight) for ZA Alloys
	ZA - 8		ZA - 12		ZA - 27
	Ingot	Casting	Ingot	Casting	Ingot	Casting
Al	8.2 - 8.8	8.0 - 8.8	10.8 - 11.5	10.5 - 11.5	25.5 - 28.0	25.0 - 28.0
Mg	0.02 - 0.03	0.01 - 0.03	0.02 - 0.03	0.01 - 0.03	0.012 - 0.020	0.01 - 0.02
Cu	0.9 - 1.3	8 - 1.3	0.5 - 1.2	0.5 - 1.2	2.0 - 2.5	2.0 - 2.5
Fe (max)	0.035	0.075	0.05	0.075	0.07	0.075
Pb (max)	0.005	0.006	0.005	0.006	0.005	0.006
Cd (max)	0.005	0.006	0.005	0.006	0.005	0.006
Sn (max)	0.002	0.003	0.002	0.003	0.002	0.003
Ni (other)	-	-	-	-	-	-
Zn	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.
Color Code ASTM B908	Blue		Blue		Blue
Color Code ASTM B908