Zinc is a multipurpose and important metal with important roles in a wide industrial, commercial, and biological applications. Zinc is used industrially, in construction, and for protective coatings because of its high corrosion resistance and bluish-silver appearance. One of its most valuable properties is its ability to form very strong alloys, especially with aluminum, copper, and magnesium, and it greatly improves the strength and durability. Concerning manufacturing processes like die casting, these characteristics make zinc extremely suitable. Zinc is also known as a special material in the context of the automotive industry because there is no other material with such mechanical properties and at the same time with so many manufacturing advantages. It can be used in creating highly complex and detailed shapes with little machine work, which makes them perfect for both decorative and functional vehicle components. In addition to its low melting point, which makes for lower energy use during production, as per global sustainability objectives. Zinc’s importance is increasing as automotive technology evolves. Most airplane system parts can now be made from it because it supports high volume production with excellent part consistency, which makes it a critical material, not just for the current system designs, but also for their new designs for the future.

Vad är pressgjutning av zink?

Zinkdruckgjutning är en precisionstillverkningsprocess som innebär att smält zinklegering injiceras i en anpassad form (även kallad gjutform) under högt tryck och vid högt tryck för att forma metalldelar. Den används normalt för tillverkning av komplexa, detaljerade komponenter med snäva toleranser, fin ytfinish och höga mekaniska egenskaper.

Zinkgjutning har utmärkta mekaniska egenskaper och kombinerar hög precision på samma gång. Det gör det möjligt att tillverka invecklade delar med snäva toleranser och slät ytfinish och är användbart för de krav som ställs på dagens fordonsdesign.

Varför zink? Viktiga materialegenskaper

På grund av flera unika egenskaper är zink att föredra i pressgjutningsprocessen.

High Strength and Ductility

Eftersom den är starkare än många andra metaller som pressgjuts används zinklegeringar i tunnväggiga applikationer.

Excellent Dimensional Accuracy

Zinkgjutning är en del som bibehåller sina former och storlekar med stor konsistens vilket hjälper till att skära bort från efterbehandling.

Överlägsen korrosionsbeständighet

Zink är naturligt motståndskraftigt mot korrosion, särskilt om det förses med ytterligare beläggningar. Det är avgörande för delar som används i fordon under de olyckliga väg- och väderförhållanden som råder.

High Fluidity

Den smälta zinken flyter mycket lätt, och dessa detaljer med små detaljer och tunna väggar kunde gjutas med framgång.

Cost-Effective Tooling

Zinkgjutning har fördelar med verktyg med lång livslängd jämfört med aluminium eller magnesium; därför är det mer ekonomiskt fördelaktigt att använda zink om man vill ha en stor produktionskörning.

Återvinningsbarhet

Bilindustrins övergång till ökad hållbarhet innebär också att zink är ett miljövänligt material som är 100% återvinningsbart utan att förlora sina egenskaper.

Manufacturing Process: Step-by-Step Overview

1. Design and Tooling:

CAD-programvara används av ingenjörer för att konstruera komponenten. Därefter tillverkas en stålform med hög precision och ett stort antal hålrum för att bygga flera delar i en enda cykel.

2.  Melting the Zinc Alloy:

Vid cirka 420°C smälts zink, lägre än aluminium och med betydligt lägre energikostnader.

3. Injection:

Vanligtvis sprutas den smälta zinken in i formen med ett tryck på 1.500 - 25.000 psi, tillräckligt högt för att säkerställa att formen fylls snabbt och jämnt.

4. Cooling and Solidification:

När zinklegeringen kommer in i verktyget kyls den snabbt och stelnar (på några sekunder).

5. Ejection:

Utskjutningsstiften skjuter sedan ut den nyformade delen från verktyget.

6. Trimming and Finishing:

Delen kan bli föremål för ytterligare efterbehandling, t.ex. gradning, polering, målning eller beläggning, och överskottsmaterialet (flash) avlägsnas.

7. Quality Control:

Vissa komponenter inspekteras med avseende på måttnoggrannhet, ytdefekter och mekanisk integritet, vilket ofta sker med automatiserade system eller 3D-skannrar.

Common Zinc Alloys Used in the Automotive Industry

Inom fordonsindustrin är det viktigt att välja rätt zinklegering eftersom legeringens egenskaper spelar en viktig roll för prestanda, tillförlitlighet och kostnadseffektivitet. Tillverkarna kan matcha material till specifika applikationer beroende på vilken balans mellan styrka, duktilitet, flytbarhet och korrosionsbeständighet som olika legeringar har att erbjuda i varierande grad. De vanligaste zinklegeringarna i gjutning av bilar anges nedan.

1. Zamak Alloys (Zinc-Aluminum Alloys)

Det primära legeringselementet i en familj av zinklegeringar som kallas zamak är aluminium vid ca 4%. Namnet kommer från de tyska namnen på de metaller som används: Zink, Aluminium, Magnesium och Kopper (koppar).

Zamak 3:

• Det är den mest använda zinklegeringen för pressgjutning.
• Ger utmärkt dimensionsstabilitet, god ytfinhet och gjutbarhet.
• Dessa ytor är vanliga i interiörkomponenter som dörrhandtag, knoppar och lister.

Zamak 5:

• Den är något mer kopparhaltig än Zamak 3 och erbjuder högre hållfasthet och hårdhet.
• Lämplig för applikationer med mekanisk belastning, t.ex. konstruktionsfästen.

Zamak 2:

• Den starkaste och hårdaste av Zamak-legeringarna.
• Detta används i låssystem eller växelhus där slitstyrkan är kritisk.

2. ZA Alloys (Zinc-Aluminum)

ZA-legeringar (ZA-8, ZA-12, ZA-27) har högre Al-innehåll än Zamak och har högre hållfasthet och slitstyrka. De används i allmänhet vid gravitationsgjutning, i vissa fall förmodligen även vid pressgjutning.

ZA-8:

• Innehåller 8% aluminium.
• Ger god hållfasthet och måttliga gjutegenskaper.
• Lämplig för strukturella komponenter i lättviktsfordon.

ZA-12 and ZA-27:

• Svårt att gjuta, men högre hållfasthet.
• Används i halvstrukturella applikationer eller delar, där det utsätts för friktion.

3. ACuZinc5

Det är en speciell zink-koppar-aluminiumlegering avsedd att uppnå Zamaks gjutbarhet och ZA-legeringarnas hållfasthet.

• Extremt hög hållfasthet och överlägsen slitstyrka.
• Applied in gear housings, actuators, and mechanical linkages in automotive systems.
• The change material is ideal for replacing machined bronze and steel in applications where durability is necessary.

4. EZAC (Enhanced Zinc-Aluminum-Copper)

A relatively new alloy, very high in strength and creep resistance up to elevated temperatures, EZAC is.

• Good for parts that have to hold shape and strength even under the load, for example mounting components or engines.
• It offers twice the strength of Zamak 3, but requires more advanced tooling.

5. Zinc-Nickel Alloys

Zinc-nickel plate is less common than zinc die casting for these areas, but it is frequently used to improve corrosion resistance (especially salt and moisture) for under the hood or undercarriage parts.

• Att välja rätt legering
• The selection of zinc alloy depends on several factors
• Mechanical requirements (tensile strength, impact resistance)
• Surface finish needs
• Cost and production volume
• Exposure to environmental stress (heat, corrosion)

For that reason, engineers frequently work with material scientists and suppliers to choose an alloy that is as well suited to the task as cost may permit, meeting both performance and cost constraints.

Role of Zinc Die Casting in the Automotive Industry

Zinc die casting has great importance in automotive manufacture due to high precision, high strength and economical make of small-to medium sized components. This process offers the means to produce complex parts of high precision in a very short time period and is excellent for high volume automotive applications.

Excellent mechanical properties of zinc alloys, such as durability, corrosion resistance, and dimensional stability, are obtained. These are the things that make zinc the best choice for door handles, brackets, locks, emblems, etc., as an auto part. This also provides easy plating or painting since it has a smooth surface finish.

Although zinc is heavier than aluminum or magnesium, it can be competitive for applications where weight is not the highest priority in terms of strength and detail. Due to its low melting point it requires less energy usage and has a long tool life. Zinc also is 100% recyclable, which supports accelerating the automotive industry’s promotion of sustainability.

Zinc die casting is still providing reliable and high-quality solutions for automotive demanding applications as vehicle designs evolve.

Physical and Chemical Properties of Zinc 

Fysikaliska egenskaper hos zink

1. Appearance:

The thermoelectric bluish silver or grayish metal has a shiny metallic luster when freshly polished.

2.  Density:

Since at room temperature Zinc has a density of about 7.14 g/cm³, it is moderately heavy in comparison with other metals.

3. Melting Point:

However, at a relatively low temperature of 419.5°C (787°F), zinc is suitable for thermal processes, such as die casting, where low energy consumption is desired.

4. Boiling Point:

Zinc boils at 907°C (1665°F).

5. Hardness:

Zinc is about 2.5 on the Mohs scale of hardness, which makes it not too hard compared to steel, but not too soft as pure tin or lead are.

7. Electrical Conductivity:

However, while copper and silver are very good conductors of electricity, zinc is not quite as conductive. Because of this property, it is often used in batteries and electroplating.

8. Thermal Conductivity:

The moderate thermal conductivity of zinc makes it useful in managing heat, but it is less efficient than aluminum.

9. Malleability and Ductility:

Zinc is brittle, and thus can easily break at room temperature. It is however malleable when heated to around 100–150°C (212–302°F), one can easily shape them.

10. Crystal Structure:

In addition binary compounds of zinc are zinc crystallizing in a hexagonal close packed (hcp) structure which affects the mechanical properties especially the brittleness at lower temperatures.

Chemical Properties of Zinc

1. Reactivity with Air:

After coming in contact with air, zinc forms a thin layer of zinc oxide (ZnO) on the surface. Zinc on the top side prevents deeper corrosion and is therefore very resistant to atmospheric oxidation rusting.

2. Reactivity with Acids:

Dilute acids like the dilute acid hydrochloric acid (HCl) can react easily with zinc to give up hydrogen gas (H₂). Therefore, this property makes zinc useful in galvanization and sacrificial anodes for corrosion protection.

3. Amphoteric Nature:

Zinc is amphoteric, and can be acted upon by both acids and powerful bases. For example it reacts with sodium hydroxide (NaOH) to give sodium zincate.

4. Alloy Formation:

Zinc readily alloys with several metals, including copper, to produce brass, aluminum, magnesium, and many other metals.

5. Oxidation States:

The +2 (Zn²⁺) oxidation state of zinc is the most common. This oxidation state is combined with zinc compounds such as zinc oxide (ZnO) and zinc sulphate (ZnSO₄).

6. Resistance to Water:

Pure water does not react with zinc at room temperature, but at higher temperatures, zinc can react with it, slowly forming hydrogen gas and zinc oxide.

7. Galvanic Activity:

The anode material, zinc, is very effective because it readily loses electrons in galvanic cells (batteries).

Zinc vs Other Materials in Automotive Applications

Unlike aluminum, magnesium, plastic or steel, zinc die casting has several advantages. Zinc shines for its key performance and cost in automotive design, and while each material may have its place in automotive design, zinc is particularly effective in those parameters.

Zinc vs Aluminum:

In a form that is often selected for its light weight, aluminum is too weak and too soft at low thicknesses compared with zinc. Additionally, zinc provides better dimensional stability and additional complex geometries don’t require extensive machining. Tooling for this kind of casting also tends to last for longer periods, so it means that long term production costs are lower.

Zinc vs Magnesium:

Zinc is lighter than magnesium but is more expensive when bought without special coating. However, zinc alloys offer excellent corrosion resistance and do not require any additional surface treatments to make them resistant in most environments. Also, casting zinc provides better casting precision and finish.

Zinc vs Plastic:

However, plastic is lightweight, inexpensive, but comparatively weaker, does not withstand temperatures very well and is less durable than metal. Zinc components withstanding wear, impact or load bear are a solid alternative when structural integrity, lifespan and resistance to damage from impact or wear are important, in particular where movement or load carrying is involved.

Zinc vs Steel:

Steel is a good material that is strong and is quite commonly used in structural applications, but it is much heavier, and in many cases, more costly to form into ornery shapes. Zinc die casting, because it produces near net shape parts with minimal post processing, is well suited in cases where small and medium sized components are to be produced.

In general, zinc provides a good balance between mechanical strength, cost, formability, and surface finish and is therefore an excellent material for automotive parts regardless of their function.

Summary Table of Zinc’s Key Properties

Applications of Zinc Die Casting in Automotive Manufacturing

A wide range of components for vehicles can be processed via zinc die casting. Some of which are most common, such as:-

1. Invändiga komponenter:

• Dörrhandtag
• Seat belt hardware
• Dashboard control levers
• HVAC knobs and switches

The components in these are high precision, tactile feel needs to be good, and the fit has to be a great finish. The ability of zinc to provide fine surface detail and dimensional accuracy is suited for these parts that are visible and used frequently.

2. Utvändiga komponenter:

• Emblems and logos
• Door and trunk locks
• Mirror brackets
• Wiper system components

Since noise, however, often indicates the cause of noise and the location of its cause is not as important as the noise itself, corrosion resistance and strength are used for use after environmental exposure and give appearance and function.

3. Komponenter under huven:

• Carburetor parts
• Fuel system parts
• Valve bodies
• Timing belt covers

Both thermal stability, strength and wear resistance are essential for these parts. Complex geometries, high precision tolerances and fluid engine system applications are achieved through zinc die casting.

4. Strukturella delar:

• Fästen
• Mounting plates
• Chassis supports (in smaller vehicles)

Although not used for primary load bearing structures, zinc components have stiffness and reliable mechanical properties that make them useful in supporting frames and assemblies.

Zinc’s flexibility meets decoratively and functionally said requirements in all classes of vehicles. Because of its capacity to cut post-processing, EMI shielding, and component consolidation, zinc die casting extends to more and more electric and conventional platforms.

Fördelar med pressgjutning jämfört med andra pressgjutningsmaterial

Although aluminum and magnesium have also been used in the automotive sector, zinc has an advantage:

It is easy to see that for small to medium sized components in which precision and strength are of great importance, zinc die casting is a very good option.

Utmaningar inom pressgjutning av zink

Zinc die casting has some disadvantages:

Vikt:

Zinc is too heavy to use in electric vehicle chassis and other applications where weight reduction is critical because it’s heavier than aluminum or magnesium.

Termiska egenskaper: 

Thermal conductivity of zinc is lower than that of aluminum, so it is not suitable for heat dissipation parts like engine radiators.

Begränsningar i storlek:

For example, the tools cannot be used to cast very large components, and solidification defects can occur.

Yes, given intelligent engineering and hybrid material design, most of these challenges can be addressed.

Miljö- och hållbarhetsfaktorer

Zinc die casting stands out because the global automotive industry leans towards greener practices.

100% Återvinningsbarhet:

Zinc casting scraps are collected and reworked without any degradation.

Energieffektivitet:

Since aluminium has a much higher melting temperature, the energy consumption is significantly lower than with aluminium.

Lång livslängd för verktyg: 

It lengthens the die life, lessening the frequency of tool replacement, which means less waste and time without production.

As a result, companies working towards meeting more rigorous environmental regulations are drawn to zinc as it is an excellent option that won’t compromise quality or performance.

Innovationer och framtida trender

Tunnväggsteknik:

Dies that have been advanced, and more fluid zinc alloys, have now enabled parts with extremely thin walls, reducing weight without losing strength.

Hybridmonterade enheter: 

Also, zinc parts are being used more and more in combination with plastics or other metals for multifunctional parts.

Elektriska fordon (EV): 

EVs need compact and robust components for battery housings, control systems, and connectors, and zinc is showing promise because of its precision and as an EMI (electromagnetic interference) shielding metal.

Smarta verktyg: 

In mass production, the use of AI and machine learning for die maintenance also helps to reduce the die life and defects.

Slutsats

Pressgjutning av zink is more than a manufacturing method; it’s a winning strategy to achieve the competitive automotive edge. It presents a combination that is optimal regarding mechanical strength, design flexibility, cost efficiency, and sustainability. Since vehicles are moving towards becoming lighter, more environmentally friendly, and more sophisticated, zinc die casting has an important role to carry it forward as the next generation of automotive components. Zinc has huge use from small interior knobs to powerful under hood structures in automotive manufacturing. Once innovations continue to refine their application, the years ahead will deliver even wider adoption on conventional, hybrid, and electric vehicle platforms.