Chemistry Project – Physical and Chemical Properties of Metals and Non-Metals
Contents: Physical properties of Metals Chemical properties of Metals Physical properties of Non-Metals Chemical properties of Non-Metals
PHYSICAL PROPERTIES OF METALS
Physical properties of Metals: Physical properties are an important way of distinguishing one material to another. In the study and application of metallurgy (study of physical and chemical behaviour of metallic elements), physical properties are often considered a broader category than mechanical properties, but not all properties overlap. Physical properties are most easily distinguished from mechanical properties by the method of testing. While mechanical properties require force to be applied to obtain a measurement, physical properties can be measured without changing the material.
Physical properties do change in different environments. For example, most metals have a higher density at lower temperatures due to the principles of thermal expansion (tendency of matter to change it’s shape, area, volume & density in response to a change in temperature) and contraction (the decrease in size of atoms and ions on the elements). Colour and appearance, which are also physical properties, change based on a number of environmental properties .
Physical properties of metals include: Corrosion Resistance Density Melting Point Thermal Properties: Heat Capacity Thermal Conductivity Thermal Expansion Electrical Conductivity Magnetic Properties
Corrosion Resistance: Corrosion is a process in which a material is reduced to a more stable state by chemical reaction, often related to the atmosphere service conditions. Many types of corrosion occur. Rust, a common sight on the unprotected products made of ferrous metals, is one of the most common forms of corrosion. Corrosion resistance , on the other hand, is the material’s ability to resist the reaction to move towards a more stable state in its environment. Raw aluminium, silicon, titanium and their alloys are naturally corrosion resistant due to an unreactive layer that quickly forms on their surfaces. A common alloy for many applications requiring corrosion resistant is stainless steel. Unlike carbon steel, stainless steel alloys are able to resist surface corrosion when exposed to environments that would normally cause corrosion, including wet, acidic or high heat.
Density: The density of an object is determined by a simple formula: the object’s mass (M) divided by it’s volume (V). At first, the practical application of density was to determine the authenticity (quality) of gold, as in the story of the golden crown. Gold is an excellent candidate for testing density, because it is a much denser material than other metals, with an average density of 1,206 lbs (547 kg). per cubic foot. Alloys more commonly used in manufacturing have lower densities. Steel averages around 494 lbs (224 kg). per cubic foot, while stainless steel is a bit less.Titanium is about half the density of steel and aluminium is about one-third. Practically speaking, this means that a part made of steel will weigh approximately three times more than the exact same part of aluminium. However, steel has other advantages like hardness and strength, and so lower volumes or thicknesses of material can provide the same or better performance, comparatively. Eagle Alloy and Eagle Precision often produce complex, thin-walled castings from different carbon and stainless steel alloys. The alloy affects the design, production process and finishing techniques used to manufacture each cast part.