Main studies carried out during March:

- microhardness measurements of the melt - spun ribbons with chromium, titanium, and vanadium addition in the as- cast state,
- preparation of new pentanary alloy,
- investigation of thin foils with titanium and vanadium addition using TEM,
- trials of obtaining melt spun ribbons from ingot of pentanary alloy
- TEM investigation of thin ribbons with zirconium addition – analysis of microstructure evaluation after annealing
- XRD analysis of quaternary ingot with copper and silicon addition,
- analysis of the results obtained so far,
- participation in seminars and lectures,

This month I was focused on 3D EBSD experiments on aluminium 6013 alloy after severe plastic deformation. The new software that was installed 2 months ago works quite well. Apart from data collection, data post processing was also carried out. Since there are no well established methods for data processing, final results are quite arguable. One of the goals in my work is to solve the issue.

In March microstructural research on KoBo deformed materials continues. Two sample types of KoBo'ed hexagonall materials were prepared: 8 mm discs from CP Grade 2 titanium and resin immersed 2 mm zinc wires (oriented to observe transverse section). Samples were prepared for EBSD investigations. In case of titanium which has become stronger after KoBo deformation (675 Mpa compared to 345 MPa of standard CP grade 2 Ti) observed microstructure consisted of mixture of elongated twisted grains (length ~7 um) and smaller equiaxial grains (diameter ~1 um). Some initial problems with surface preparation for EBSD (lots of unsolved diffractions) were solved by use of thicker sample. This allowed for better control over polishing part of preparation and resulted with higher rate of indexed diffractions.
Other type of samples (pure zinc) where also investigated with EBSD technique. Microstucture consisted of smaller and larger equiaxed grains with dimensions grouped around 15 and 40 micrometers. Interesting observation was made during analysis of image quality factor. Distribution of qf (which can be connected to local strains related to crystallographic defects) suggests that zinc processed by KoBo technique poses composite like structure. This structure consists of undistorted grains and relatively thick areas along grain boundaries with high level of residual strain. Such an arrangement of features could be used to explain some of the unusual mechanical behavior observed in Zn KoBo.

Were prepared with the sleeve opening and closing wedges of pure magnesium and magnesium test system - phosphorus. Phosphorus as an element of a low boiling point (below the melting point of magnesium) had to be trapped in the prepared sample, that can not be evaporated. Naważono 10% by weight. red phosphorus powder and tightly locked up in the magnesium sleeve and then placed in a graphite crucible in the furnace - all held in a chamber filled with argon. Measurement of the temperature inside the oven was difficult to implement, since the thermocouple touches the outer wall of the crucible, so that the results of measuring the temperature indication treated. When a longer residence time of the sample in the furnace is still kept its shape at a temperature substantially above the melting point of pure magnesium was decided to puncture the sample graphite rod. Derived from a sample methodology used consisted of two parts, which were frayed appearance, they lacked firmness, crispness, and it was characterized by a distinctive odor, probably resulting from addition of phosphorus.

My research in March:

My research in March:
Samples prepared from alloys (cast during previous month) has been prepared by standard metallographic procedures for SEM and XRD evaluation. Samples for optical microscopy have been etched in a solution of acetic picral to reveal grain boundaries. SEM (FEI E-SEM XL30) has been used to confirm chemical composition of the samples (EDS) and to observe the microstructure. XRD has been performed to examine the phases in the as-cast alloys. EDS analysis has confirmed the composition of the alloys. X-ray diffraction examination have revealed the presence of α-Mg phase and the probability of the presence of Mg6Ca2Zn3 phase in ternary alloys.