PSI - Issue 50

Andrey Polyakov et al. / Procedia Structural Integrity 50 (2023) 228–235 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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pumps, bushings, etc. make 70% or more of the total consumption of iron powder products and compositions based on them). A more detailed list of automotive parts manufactured by powder metallurgy methods can be seen, for example, in the booklet Metal Powder Industries Federation, which unites manufacturers of powders, products from them, equipment for the production of powders and products mainly from North America, as well as Europe and Asia (https://www.mpif.org/MarketPM/PM_AutoCat_Parts_Listing.pdf). An important technological technique for increasing the density and strength of powder parts, improving their microstructure, including iron powder and compositions based on it, is the rational alloying of the charge. Moreover, when developing the technological parameters of the process of compacting powder blanks, it is important to ensure the possibility of their subsequent thermomechanical processing in the unsintered state, which can significantly reduce production costs.

Fig. 1. The market structure of powder parts in Europe in 2014.

This fully applies to the extrusion process, which is one of the main technological processes of powder metallurgy. In particular, cold extrusion expands the capabilities of powder metallurgy. So, in Tae-Wan Ku et al. (2014) the rationale for cold extrusion is given in terms of cost reduction, productivity and ductility, environmental friendliness of the technology. Cold stamping and extrusion have several advantages: minimum waste, high dimensional accuracy, reduction or complete elimination of mechanical processing, better mechanical properties than the original, due to the favorable grain structure Plancak et al. (1992). It should be taken into account that the task of obtaining materials and products with improved or fundamentally new properties from powder raw materials is associated with the creation of a structure that provides improved physical, mechanical and other properties of materials. In the manufacture of products from powder materials, an essential role is played by the nature and sequence of operations of thermomechanical processing, which largely determine the structure and properties of the finished product. In a comparative analysis of the strength properties of compacts, it should be taken into account that they significantly depend not only on the density, but also on the method of obtaining the initial powder, the size and shape of the particles, and their size distribution. In mathematical modeling of real processes, it is desirable that the dependences of the yield strength of an incompressible solid phase (compact material) on density and other thermomechanical parameters be determined experimentally, since the deformation scheme can significantly affect the value of the theoretical yield strength of a compact (non-porous) material.