Composite Extrusion Modelling (CEM) is a new additive manufacturing process for metal that uses Metal Injection Moulding (MIM) materials. The MIM material is printed on a build plate using a moveable extruder. Subsequently, the printed greenparts are debinded and sintered in a two-step oven process. In contrast to beam-based additive processes, the microstructure of the part is not generated la...

Hot work tool steel (AISI H13) and high speed steel (AISI M3:2) powders were successfully co-sintered to produce hybrid tool steels that have properties and microstructures that can be modulated for specific applications. To promote co-sintering, which is made difficult by the various densification kinetics of the two steels, the particle sizes and structures were refined by mechanical milling ...

Direct metal SLS processes use a high power laser beam to selectively fuse fully metallic powder to directly produce functional metal components or tooling. As a thermal dynamic process, it inevitably causes thermal stresses, stress-induced deformations and cracking. Understanding these is very important in controlling residual stresses and stress-induced deformations. In this research, the res...

T. Wyleciał, H. Radomiak, D. Urbaniak, Częstochowa University of Technology, Czestochowa, Poland The use of coal in the steel industry, similarly as in the whole national ec onomy, is often preceded by its pre-treatment. Coal is mined in the form of big solids, but, being in such a form, it can’t be combusted, sintered, or gasifi ed. Therefore, it needs t o be appropriately grinding. In the pap...

In this work, AISI 4340 steel was produced by powder metallurgy. Samples were sintered at 1150?C for 90 min. and then cooled in the furnace. Except to those as-sintered condition, one of samples homogenized 1 h air. Other deformed temperature range 1150-930?C deformation rate 30 60% followed cooling sand, air water mediums. The grain size gradually decreased depending on or steel. Small grains ...

The world standards for conventional ceramic hardness have varying requirements for control of loading rate during the indentation cycle. A literature review suggests that loading rate may affect measured hardness in some instances. In view of the uncertainty over this issue, new experiments over a range of indentation loading rates were performed on a steel, sintered silicon carbide, and an al...

Within the scope of increase in cutting tools efficiency, a CW CO;! laser beam has been used for butt welding sintered tips containing cobalt and tungsten carbide to a medium carbon steel core. After optimization of the laser processing conditions, full penetrating, sound and homogeneous welds are observed. Hardness is found to be nearly constant across the entire weld bead cross-section. Micro...