In the Late Classic Period Yaxchilan was one of the most powerful Maya cities along the course of the Usumacinta, with Piedras Negras as its major rival. Architectural styles in subordinate sites in the Usumacinta region demonstrate clear differences that mark a clear boundary between the two kingdoms.
Answered by The Community. Making the world better, one answer at a time. Steel is not usually considered a composite, as it is macroscopically homogeneous. However, some steel types, including classical iron-carbon steel, can be considered as metal-matrix composites, as they contain a second phase... sometimes.
However, the term alloy steel is the standard term referring to steels with other alloying elements added deliberately in addition to the carbon. Common alloyants include manganese (the most common one), nickel, chromium, molybdenum, vanadium, silicon, and boron. Less common alloyants include aluminum, cobalt, copper, cerium, niobium, titanium, tungsten, tin, zinc, lead, and zirconium. The following is a range of improved properties in alloy steels (as compared to carbon steels): strength, hardness, toughness, wear resistance, corrosion resistance, hardenability, and hot hardness. To achieve some of these improved properties the metal may require heat treating.