The aluminium alloy AA6082 is used as a material for highly loaded construction parts, which means any improvement in its mechanical properties would be an advantage. The majority of approaches employed so far for increasing the mechanical properties only considered a small number of influential parameters and assumed that they were predominately independent of each other. In contrast, in this investigation a simultaneous increase in the yield stress and ductility (elongation) was achieved by considering a larger number of influencing parameters. The results of the analyses provided a new view of their influences, and the possibility to increase the mechanical properties if the process parameters in the relation with the chemical elements are closer to the optimum values.
COBISS.SI-ID: 1059934
In this study progress of the wear on the bearing surfaces of nitrided dies for aluminium (AA6063) hot extrusion is demonstrated and explained. Two groups of nitrided AISI H11 tool steel dies were analysed, with relatively short and long bearing surfaces. It was found that: (i) Relatively shorter bearing surface die exhibited two different pathways to failure, (ii) One degradation pathway was found on die with longer bearing surface, (iii) Formation of deep furrows originating from craters was observed, (iv) High density of adhesively removed islets lowers shear strength of nitrided layer.
COBISS.SI-ID: 1072222
Metallurgical characterization of a sword blade dating from the second half of the 15th century found in central Slovenia was performed in order to determine its chemical composition, microstructure, microhardness, and to obtain insight into the methods of manufacture. The results show that the sword was manufactured from a single wrought iron billet. The surface of the sword was carburized. No evidence of quenching was found. The ferritic microstructure is concentrated in the core, and the pearlitic in the outer layer of the blade. This is nice example of bulk functionaly graded material.
COBISS.SI-ID: 1085534
In order to improve the hot workability of AISI D2 tool-steel ingots during several heats hot deformation process, laboratory hot-compression tests as well as industrial investigations of the carbides' behaviour were carried out. The conditions that led to the occurrence of undesired, oversized carbides in the matrix were estimated and explained. It was found that to high soaking temperature results in an increased size of carbides which decreases hot workability. The results of industrial investigations show that area fraction of carbides after the end of each deformation cycle remains almost constant, but their mean size more than double during deformations in several heats which implies that the final microstructure is not dependent primarily on the last soaking-deformation cycle but depends on entire processing history, i.e. hot workability over several hot-deformation cycles can change considerably from cycle to cycle.
COBISS.SI-ID: 1287775
This paper presents an improved monitoring system for the failure detection ofen graving tool steel inserts during the injection molding cycle. The obtained results revealed that such a system could be used successfully as an improved tool for monitoring the integrity of an injection molding process.
COBISS.SI-ID: 16888854