1. chevron_left 記事

The Basics of Nonferrous Metallurgy

142 記事

Aluminum-Magnesium-Silicon (6000) Alloys

The main components of the alloys are magnesium and silicon to form Mg2Si. There is often an iron corrector such as manganese or chromium; occasionally small amounts of copper or zinc to improve the strength without substantial loss of corrosion resistance; boron in conductors to remove titanium and vanadium; zirconium or titanium to control the grain size. Lead and bismuth are sometimes added to improve machinability, but they are less effective than in magnesium-free alloys.

Aluminum-Silicon Alloys

Castings are the main use of aluminum-silicon alloys, although some sheet or wire is made for welding and brazing, and some of the piston alloys are extruded for forging stock. Often the brazing sheet has only a cladding of aluminum-silicon alloy and the core consists of some other high melting alloy.
The copper-free alloys are used for low- to medium-strength castings with good corrosion resistance; the copper-bearing for medium- to high-strength castings, where corrosion resistance is not critical. Because of their excellent castability, it is possible to produce reliable castings, even in complex shapes, in which the minimum mechanical properties obtained in poorly fed sections are higher than in castings made from higher-strength but lower-castability alloys.

Aluminum-Zinc-Magnesium Alloys

All commercial aluminum alloys that comprise this group contain more zinc than magnesium. There are a few commercial alloys with Zn:Mg < 1, but they have been considered with the aluminum-magnesium alloys because their behavior and structure are much closer to those of aluminum-magnesium alloys than of aluminum-zinc-magnesium. Al-Zn-Mg alloys can be used for both castings and wrought products, but because of the poor castability, the bulk is in the form of wrought products.

Amazing Aluminum-Lithium Alloys: Part One

Commercial aluminum-lithium alloys are targeted as advanced materials for aerospace technology primarily because of their low density, high specific modulus, and excellent fatigue and cryogenic toughness properties. The principal disadvantages of peak-strength aluminum-lithium alloys are reduced ductility and fracture toughness in the short transverse direction, anisotropy of in-plane properties, the need for cold work to attain peak properties, and accelerated fatigue crack extension rates when cracks are micro structurally small.

Amazing Aluminum-Lithium Alloys: Part Two

Lightweight aluminum alloys, long studied by metallurgists and prized by aircraft makers, continue to be improved, more recently by the careful addition of lithium. The results could save fuel and extend the lives of aircraft.
In part two of this series we learn what held this technology back for decades. We also see how two new alloys measure up against a legacy aluminum.

Ballistic Protection Efficiency of Aluminum Alloys

Generally, the basic aim of armoring is to ensure maximum ballistic protection against high velocity projectiles of different type and armor-piercing (AP) ammunition. The combinations of extremely hard metallic and non-metallic materials offer effective ballistic protection. Composite armoring materials are two-layered and multi-layered combinations of aluminum, steel, titanium, ceramics, epoxy/glass composite, resins etc.