Internal factors are those inherent to powders, or characteristic of the nature of powders. These include particle size, particle shape, and cohesiveness. In general, larger particles have higher angles of repose. However, very small particles may exhibit cohesiveness due to the electrostatic effect, which increases the angle of repose (Ref 31, 32, 33). Because spherical…
Both internal and external friction values are important when characterizing the flow properties of a metal powder. Internal friction is caused by solid particles flowing against each other and is expressed by the angle of internal friction and the effective angle of internal friction. Both can be determined during the course of measuring cohesive strength with a…
Apparent density of a metal powder, or the weight of a unit volume of loose powder expressed in grams per cubic centimeter, is one of the fundamental properties of a powder. This characteristic defines the actual volume occupied by a mass of loose powder, which directly affects processing parameters such as the design of compaction tooling…
The bulk density of a material is the ratio of the mass to the volume (including the inter-particle void volume) of an untapped powder sample. The tapped density of powders or granulates is an increased bulk density attained after mechanically tapping a cylinder containing the sample. Analysis of Bulk and tapped density of powder give you…
Additive Manufacturing Metal powders are widely used as a material for additive manufacturing. Selective laser melting (SLM) for example, is an enhanced powder metallurgy process that follows a computer-aided design (CAD) to direct a high-powered laser to melt and then fuse metallic powders together in a layer-by-layer manner to form a final part. This process…
Different metal powders require different ways of production due to their distinct physical and chemical characteristics. For decades, various manufacturing processes of metal powders have been devised, developed, and applied. Some of the most widely used methods are described below. Machining & grinding Milled metal powders are produced by having metals physically ground by a…
The properties of the fabricated end product made from base metal powders are dependent on the characterisation of the powder from production. The main characteristics that describe metal powders are as follows: · Morphology – describes the shape of the particle and its contour surface (Table 1) · Granulometry – specifies particle size and size distribution · Chemical composition…
Powder metallurgy is a branch of material science which deals with manufacturing of products from the powders of the materials. This metallurgical process is gaining importance day by day. Some of the most important applications of the powder metallurgical parts are a. Porous bearings which are prepared by this process are used for starters, clutches,…
Various MPIF award winning Powder Metallurgy components. (Photo courtesy MPIF) Powder Metallurgy is a technology which involves spending considerable time and effort in converting the starting material to the required powder form and then even further time and effort in “sticking” the material back together again to produce a more or less solid object. On…
The basic Powder Metallurgy process for structural press and sintered components Powder Metallurgy comprises a family of production technologies, which process a feedstock in powder form to manufacture components of various types. These production technologies generally involve all or most of the following process steps: Powder production Virtually all iron powders for PM structural part…