Ductility vs. Malleability

Main Difference

The main difference between Ductility and Malleability is that Ductility is the capability of a metal that can undertake tensile stress, whereas Malleability is the capacity of a metal to go through compressive stress.

Difference Between Ductility and Malleability

Comparison Chart

Ductility vs. Malleability

Ductility mentions the capacity of a metal to expanse in tensile stress, while malleability mentions the capability of a substance to distort and can change shape in compressive stress. The external force which is applying on ductility is the tensile stress, while the external force which is applying on the malleability is the compressive force/stress.

Materials that have ductile property could be rolled and trolled into wires, and it is the critical property of a ductile because the tensile force is acting on the substance, whereas materials that contain malleable property could be rolled into sheets and papers, forging, extrusion, etc. actions because a compressive force is acting on that substance.

For measuring the ductility of a substance, a bend test is used; on the other hand, malleability is generally measured by the capability to withstand pressure and force. A grain size could affect the properties of ductile metal; on the contrary, malleability could be affected by a substance having a crystal structure. The ductility of a solid substance usually decreases with the increase in temperature; conversely, the malleability of a solid substance used to increase with the increase in temperature.

Metals and substances that display ductile property normally show high malleability such as silver and gold because both of them show excellent properties of ductility and malleability; on the other hand, substances and other materials which show high malleability may not exhibit good ductility such as lead and cast iron which shows high malleable property but poor ductile property.

The theory of ductility describes that the capability of a material to stretch into a wire or a chain when it is pulled from all ends; on the other hand, the theory of malleability mentions that the capacity of a metal to produce a sheet-like structure and change its structure when a compressed force acts on all the ends. By influential the degree in ductility in which the solid material could go thorough plastic distortion without having a fracture or change in shape; on the contrary, in malleability, it is determined the amount of pressure a solid material could withstand without breaking.

What is Ductility?

Ductility refers to the amount of the capacity of a solid material to distort plastically in external tensile force. Tensile stress defines as the force that is applied at both ends of a solid material to pull away from each other when a stress is applied to that material. Plastic distortion in ductility is happened because of tensile stress.

When a tensile stress is applied lengthwise to a single axis, then the material will be rolled into a wire or could be changed into chains without having a fracture. A grain size could affect the properties of ductile metal because when smaller the grain size, then because of greater resistance, the harder the motion of dislocations. Therefore, the ductile property of a material decreases, but with larger grain sizes, the property of ductile material increases because of lower resistance.

Ductility is obliged to the capability of metal atoms when they slip over each other and distort in stress. This property also proportional to the change in temperature because when metal is heated and change in temperature occurs, then ductility increases. Though, lead shows an exclusion behavior when more heated and becomes more brittle.

Metals and substances that display ductile property normally show high malleability, such as silver and gold, because both of them show excellent properties of ductility and malleability. Ductility is implicit by the tensile stress of a material in which greater the tensile stress, advanced the ductility, and easier to expanse the material.

For measuring the ductility of a substance, a bend test is used. This test is done by twisting the sample to a determined position until it fractures. The structures of Alloys are not pure, so that’s why they are highly ductile materials. Some materials like carbon are considered as less ductile because steel can be made more ductile by increasing the composition of carbon.

Applications of Ductility

• Used to produce wires
• Tubes
• Various other vehicle parts

Examples of Ductility

• Copper: It displays high ductile properties.
• Bismuth: It expresses relatively low ductility and tends to break easily due to tensile stress.

What is Malleability?

Malleability refers to the degree of the capability of a solid material to bend plastically in external compressive stress. Compressive stress is the ability of stress to shorten the proportions of material by constructing its volume smaller. Metals are considered as highly malleable such as the sea of electrons that are nearby the positive metal ions, and to survive with their small volume, they can regulate themselves.

A material having malleable property could be pressed, rolled into thin sheets and papers, forging, extrusion, and hammered without breaking the malleable material. Many different materials display different malleability according to the arrangements of a crystal structure in them.

Malleability could be affected by a substance having a crystal structure. For instance, NaCl consist of an ionic framework that usually requires negative and positive ions to be positioned in a particular area so, when pressure or force is applied, the ions are not capable of displacing and the framework of a crystal becomes broken. Therefore, sodium chloride (NaCl) is not considered as malleable material. In comparison, Cu is considered a highly malleable material because it can adjust its crystal structure when force or pressure is applied.

Applications of malleability are that it is widely used to make many objects by making modifications in their shapes and structures. Various examples of malleability are Gold, Silver, Iron, Copper, Aluminum, Tin, Lithium, etc.

Conclusion

The above discussion concludes that the ductility is the capacity of a metal to expanse in tensile stress and usually decreases with the increase in temperature, while malleability is the capability to change shape in compressive stress and increase with the increase in temperature.