"A man has got to know his limitations", a great man once said. This holds true for materials as well.
With the core of the planet being molten, the surface largely water, and even organic beings almost exclusively liquid in nature, the liquid state is a common state for matter of Earth.
Melting is the process through which heat changes a substance from solid state to liquid state. Some substances are more easily converted than others and are said to have a lower melting point than those that require more heat to cause this change.
These theoretical melting points are generally spoken of assuming an air-pressure equal to that at sea-level. Melting and boiling points change with increases or decreases in pressure. That is the reason that water does not turn to steam as easily in a pressure cooker or an autoclave.
Water is the most common liquid state substance on the surface of the planet, but even metals can be easily found as liquids. Mercury is used in thermometers because of its ability to stay liquid at low temperatures and because of its high boiling point. The element Gallium can be transformed from solid to liquid as easily as placing it on one’s palm.
True Metals are chemical elements that generally exhibit traits of high electrical conductivity, luster, and or malleability. They are defined through their positions in the Periodic Table of elements, and are grouped into families such as Alkali Metals, Alkaline Earth Metals, Transition Metals and Rare Earth Metals.
In addition many alloys can be created, some more difficult than others, by combining metals with other metals, and/or non-metallic elements. When so combined, the result is said to be alloyed.
These alloys take on interesting characteristics, unique to the proportions combined. Some alloys will actually melt at a lower melting point than either of their component substances alone. When the proportion results in the lowest possible melting point for the combined substances, these alloys are said to be ‘Eutectic’, or an Eutectic Alloy.
For example: Lead typically melts at 327 C and Tin at 231 C. When combined at a 67% Lead to 33% Tin proportion, the Lead-Tin solder reaches its lowest melting point of 180 C. Most lead solders have either been outlawed or are avoided because of the toxic properties of Lead.
For brazing joints, as in plumbing, Hard solder, is used. These solders are normally a copper/zinc, or copper/silver alloy. They melt at higher temperatures than the lead-tin variety, and turn back solid more slowly.
Eutectoid Steel contains 0.9% carbon (the eutectic point of the iron-carbon system) and is referred to as Pearlite, which consists of alternating layers of alpha-ferrite and cementite. This is a two-phase microstructure is found in some steels and cast irons.
With that in mind, here is a potentially useful table of melting points, for common substances often used in soldering, brazing, welding and jewelry or shop craft, as applies on Earth at sea level.
|In Order Of Melting Points|
Troy Ozs/Cu In
|Gold, 24K Pure||Au||1945||1063||19.32||10.18|
|Lynotype / Monotype||-||446||230||-||-|
|Printers Type: Tin-Antimony-Lead||-||365||185||-||-|
|Lard (pig fat)||-||110||43.3||-||-|