The malleability and ductility of a metal are core properties that aid engineers and machinists in the construction or production of complex products. Malleability has a significant impact on the efficiency of production and reliability of components. In the rest of this article we will offer essential insights into the most malleable metals. We are confident that this will help to inform your industrial and manufacturing needs.
Is Metal Malleable?
To answer this question, we need to first understand malleability. Malleability is a characteristic of any material that allows it to withstand deformation when put under pressure. When a material is beaten, hammered, rolled, or put under any other form of compressive stress, its malleability helps prevent it from breaking or getting damaged. Instead, the material takes on a new shape and form.
So, is metal malleable? Yes, it is. In fact, only a few materials on earth are more malleable than metal. As a fundamental property of metal, malleability gives it the ability to be hammered, pressed, or rolled into thin sheets.
However, while it is a generally accepted fact that metals are generally malleable, not every single one of them is malleable, and among the malleable ones, they come in varying degrees of malleability. You will find that some metals are highly malleable, while others are not so malleable.
These metals have certain things in common that enhance their inherent malleability. What makes these metals malleable, and what properties do some metals possess that make them more malleable than others?
What Makes Metals Malleable? (Factors that Determine Malleability)
The malleability of metals is typically a result of the types of chemical bonds that hold their distinct atomic structures together. So when a metal is put under compressive stress, like hammering and rolling, these atoms easily shift over each other, without causing damage. It is these shifts that cause the metal to change and take on new forms.
The ease with which the layers of atoms are able to slide over one another is determined by these three primary factors:
Metallic Bonding
Metallic bonding is the distinct bonding structure that exists in metals, in which electrons move without restraint amidst metal atoms, or in what is known as an “electron sea.”
Due to the free movement of these electrons inside the metal atoms, the latter is able to maintain a strong connection regardless of the amount of pressure applied. This makes the reshaping of metals possible without causing any fracture.
Crystal Structure
Another determining factor for the malleability of metals is their crystal lattice structure. Metals are made up of atoms, which are organized in a crystal structure. The arrangement of these atoms is flexible, especially in the face-centred cubic (FCC) and hexagonal close-packed (HCP) crystal structures.
These structures allow them to move easily past each other when the metal is put under compressive stress, without breaking. As a result, metals with this structure are very malleable and can easily take on new forms and shapes.
Temperature
The malleability of a metal can be significantly determined by the temperature it is subjected to. Typically, when a metal is heated up, the atoms increase while the strength of their bond reduces. This action makes the atoms move freely, allowing for the metal layers to slide easily over each other once pressure is applied.
However, this is not applicable to all metals. Copper, for example, can be made more malleable with heat. Zinc, on the other hand reaches malleability at temperatures ranging between 100-150°C, and then becomes brittle when the temperature increases, before finally melting.
The Most Malleable Metals
As an engineer or procurement manager charged with the crucial task of choosing the right metal for your project, it is your duty to be able to identify the various kinds of metal, which is no small feat. Below are some of the most malleable metals:
- Gold
- Silver
- Copper
- Aluminium
- Steel
- Zinc
- Iron
- Platinum
- Tin
- Nickel
Gold (Au)
Of all known metals in the universe, Gold (Au) is unarguably the most malleable. Before gold reaches its breaking point, it would need to have been beaten into sheets only a few atoms thick; that is how very malleable this metal is.
The atomic structure of gold makes it possible to beat into sheets so tiny that they become semi-transparent; this is called gold leaf. Gold also possesses another related property called ductility.
The ductility of Gold makes it possible for an ounce to be beaten and stretched into a 40-mile-long wire. Not to forget, gold also offers high conductivity. It is ideal for use in the electrical sector.
If you are an electronic/electrical engineer or procurement manager for an electronic company, your focus must be on premium materials that offer both unmatched malleability and high electrical conductivity. Gold specifically exhibits these properties, making it the perfect choice for electrical related applications.
Silver (Ag)
Following closely behind gold is its sister-element, silver. Just like gold, silver is also extremely malleable and can be beaten into thin sheets. Aside from malleability, silver boasts other properties such as antimicrobial, thermal, and electrical conductivity.
These properties make silver an excellent metal for use in medical device applications, water purification systems, and electrical applications. This metal is excellent for applications that require maximum precision.
For centuries, the malleability of silver has been leveraged in the production of both basic needs and luxury items. They include cups, utensils, coins, jewelry, amongst many others.
Due to the antimicrobial nature of silver which helps to prevent infections, this metal is commonly used in the manufacturing of medical devices. Silver is an excellent choice if you wish to achieve both maximum precision and safety in your project.
Copper (Cu)
Copper is the foundational material that holds electrical and thermal systems up. This is a highly malleable material, and easily one of the most malleable too. Copper is highly versatile due to its exceptional malleability. Without looking too far, you can find the impact of copper’s malleability around you.
The C11000 copper designation under the UNS/ASTM system is considered the standard when it comes to electrical applications. This material helps to reduce production defects.
As an electrical engineer, the materials you use must be both malleable and highly conductive. It is therefore not surprising that a malleable metal like copper is the industry standard in making essential electrical equipment, ranging from wires to transformers.
The excellent malleability properties of copper allows you to easily shape it into a wide array of electric and electronic applications. From the microscopic printed circuits on a printed circuit board (PCB) to transformer windings and busbars, the possibilities are endless.
The ASTM B8 for concentric-lay-stranded copper conductors, for example, ensures that your electrical/electronic components and enclosures meet performance and safety requirements respectively. To maintain the quality of malleable metals like copper, it is important to partner with a reputable supplier that can provide consistent high quality.
Steel
Steel is an alloy, primarily consisting of iron and carbon, with exceptional malleability properties. The science behind this high malleability of steel can be found in its crystalline structure.
Most common steels have a Body-Centered Cubic (BCC) lattice when put under room temperature conditions. This helps to provide enhanced strength, but fails to create more slip panes for the atoms.
When you heat steel to reach above 900°C (1,650°F), the structure of the material transforms into a Face-Centered Cubic (FCC) lattice known as austenite. The newly formed FCC structure offers more malleability and ductility, making the steel easy to be hammered, rolled, and pressed.
For you as a structural engineer or project manager in the construction industry, the integrity of materials is non-negotiable; quality and malleability cannot be compromised. This is where steel, an exceptionally malleable metal, becomes indispensable.
(OLD VERSION: As a structural engineer or project manager in this industry, the quality and malleability of materials can not be compromised on. This is an area where steel, an exceptionally malleable metal, is indispensable.)
For example, ASTM A36 or A36 Steel is a structural steel alloy that boasts of impressive strength and malleability. Its ability to bend under pressure rather than break makes it ideal for use in the construction of structures that can withstand natural disasters like earthquakes and typhoons.
Aluminium
Despite the fact that gold and silver are usually considered to be the most malleable metals, aluminum has proven to be the most impactful. The reason for this is clear, aluminum is an exceptional combination of malleability, durability, and light weight.
If you build car frames, you must only use materials that can be beaten into intricate shapes and curves, without breaking. Examples of these are the 6000-series aluminum alloys that are both aerodynamic and very strong, ensuring passenger safety.
In the aerospace sector, components are manufactured with materials that are very strong, yet extremely lightweight for their sizes. Malleable metals like aluminum make up an essential core in this application.
If you are a procurement manager charged with sourcing materials for the automotive and aerospace sector, malleable metals that are easily precision-formed into durable and complex components without damaging, are the target procurement.
Conclusion
Malleable metals are essential to different industries. Interestingly, even after a metal has been shaped for a function, it can be further reshaped for even more functions, ensuring durability. However, these properties only apply for high-quality malleable metals. Contact us today to get your premium copper, steel, and aluminum alloys.