Powder metallurgy was formerly known as lost art. Not like clay or other stoneware materials, the skills in molding and firing useful and ornamental metallic objects were seldom applied in the early phases of history.
Metal powders like gold, copper and bột thông công also bronze and many other powdered oxides specifically iron oxide which are used as colors, were utilized for ornamental uses in ceramic objects, used as base in paints and inks and also in cosmetics since the start of history. Powdered gold has been used in illustrating several manuscripts in the early times. The procedure in producing the powdered gold was not known, but it was possible that lots of powder were taken through granulation after the melting of the metal. Low dissolving points as well as resistance to corrosion favored the procedures, particularly in production of gold powder.
The utilization of these fine particles for pigments or decorative purposes is not a real powder metallurgy, since the important features of the current art are the creation of powder and consolidation into the hard form by means of putting force and heat at the warmth below the liquefying point of the main element.
The two principal techniques utilized to shape and consolidate the ceramics or powder metallurgy are sintering and injection of metal molding. Current improvements have possibly done to make use of speedy manufacturing techniques that use metal powder. Due to this method the powder is not sintered but melted so better mechanical power can be attained.
A much broader assortment of products might be attained from powder processing rather than straight alloying of merged materials. In dissolving procedure the “phase rule” can be applied to all untainted and merged elements and firmly dictates the sharing of solid and liquid stages which may exist for particular compositions. Furthermore, the entire body liquefying of starting substances is needed for alloying, hence, commanding annoying element, thermal and suppression limitation on manufacturing. Unluckily, the management of aluminum/iron tiny particles poses principal problems. Other materials that are principally reactive by means of atmospheric oxygen like tin is sintered in unique atmosphere or by means of temporary coatings.
In ceramics or powder metallurgy, it is probable to produce components which would disintegrate or decay. All concerns of solid-liquid stage changes may be overlooked, so powder procedures are more supple than forging, casting or extrusion techniques. Controllable character of products set by the use of several powder technologies including automatic, magnetic and some unconventional characteristics of such substances as spongy solids, aggregates and inter-metallic compounds. Competitive distinctiveness of production procedures can also be regulated strictly.