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.

In March while I was nursing my broken right hand (unfortunate fall on a ski slope, which I attempted to challenge perhaps too ambitiously) our research continued. Few samples were sent away for VSM (Vibrating Sample Magnetometer) examination. This method will allow us to study the magnetic properties of our alloys with a particular bias on their magnetocaloric behavior. This nowadays is a hot potato subject. Novel magnetocaloric materials I mean. They are a promising alternative to environment unfriendly and ozone layer harmful Freons commonly utilized for present refrigeration systems. During march as Easter was promptly approaching I studied the annealed and quenched materials by means of optical microscopy. I observed microstructures typical for martenistic phase, which constitutes a direct proof that the martensitic transformation from a higher symmetry parent phase to a lower symmetry marteniste phase takes place in the studied alloys.

Main studies carried out during February:

- microhardness measurements of the melt spun ribbons in the as- cast state and after annealing at different temperatures,
- preparation of new pentanary alloy,
- phase composition analysis of quaternary alloys with silicon and copper addition by SEM,
- XRD analysis of quaternary ingot with molybdenum addition,
- analysis of the results obtained so far,
- participation in seminars and lectures,
- preparation of an abstract for the conference ISMANAM 2012