No abstract

This study presents an approach to determine strain-stress curves of printed PLA material using 2D Digital Image Correlation (DIC) method. Besides, the present paper is an extended version of the previous study of the authors [1]. The tensile specimens were printed with a constant infill ratio and performed uniaxial tensile test with various test speeds. The elongations and local strains were measured with 2D DIC. Stress vs. strain curves were calculated from force data and DIC measurement. As a result, ultimate tensile stresses were directly proportional with the test speed increments, and maximum forces as well. The elongations were observed to decline during the test speed increments. It was underlined that the elongations gave the average results instead of the real behavior of the fractured area.

In this study, the effect of ageing processes on the wear behaviour and electrical conductivity was investigated. Prior to solid solution heat treatment at 920°C and ageing at 470°C, 500°C and 530°C for 1 h, 2 h and 3 h, respectively, the prepared samples were homogenized at 920°C for 1 h. After the ageing processes, all samples were characterized in terms of electrical conductivity, scanning electron microscope (with energy dispersive X-ray spectrum (EDS)) and hardness (HV5). In wear tests, pin-on-disc type standard wearing unit was used. As a result, starting from 1 h aged specimens, orderly increase of electrical conductivity was defined. From EDS analyses it was observed that Cr rate increases as precipitates grow. With increase of Cr rate there was also a defined rise of electrical conductivity. From the wear tests, it was observed that the least wear loss was in Cu-Cr-Zr alloy aged at 500°C for 2 h and the most wear loss was in specimens aged at 530°C for 2 h. Furthermore, it was observed that the friction coefficient values resulting from wear rate were overlapped with hardness results and there is a decrease tendency of friction coefficient as wear distance increases.

The term optical profilometry is used in relation to a group of methods used in a rapid, non-destructive, and non-contact assessment of surface topography. Those methods play a significant role in the area of a modern advanced laboratory and industrial 3D measurements. With the development of profilometric methods, a large progress in the construction of optical profilometric instruments and measuring sensors used in them, including confocal sensors based on the chromatic light aberration phenomenon (CLA) has been observed for several years. The paper shows that the Talysurf CLI 2000 multisensory optical profilometer equipped with a CLA sensor can be used in high-accuracy 3D measurements of the uncirculated and circulated coins. The assessment of such type objects characterized by a high variability of altitude can be extremely helpful in analyzing the actual metrological properties of measuring equipment used in their measurements.

Highlight Investigation of plastic friction welding nozzles used in production  Identifying the problem occurring in plastic parts after rotary friction welding  Making data entries for analysis in the current semi-melted state ABAQUS program  Analysis and simulations in the current semi-melted state ABAQUS to obtain data  Semi-melt agglomeration confinement of the developed structure by making Abaqus analysis and simulations.