Right way to plot inverse pole figures

[Italo Persechino]

Hi guys,

I am new into the world of material textures and so MTEX. I am trying to use the VPSC (Viscoplastic self consistent) in order to perform some simulations.

This code has some examples, and I am performing them first.

What I get from simulation is texture file in which there are the the angles with Bounge convention:

Enter code here...TEXTURE AT STRAIN =    1.0000
   0.605   2.692   0.605  <-- length of phase ellipsoid axes
  178.22   90.00  180.00  <-- Euler angles (deg) of phase ellipsoid axes
B       500
  108.68  125.10   44.75   0.0020000
 -116.75   50.49   45.03   0.0020000
  167.68   39.53   45.01   0.0020000
  146.43   61.79   32.61   0.0020000
  144.82   85.94    3.08   0.0020000
 -106.59    0.75    0.00   0.0020000
   16.38   59.21  -36.80   0.0020000
 -156.05  175.83  -17.43   0.0020000.
..

I import this file in MTEX (I am using the 4.0.9 version). This is the code:

%% Specify Crystal and Specimen Symmetries


clear all
close all


% crystal symmetry
CS = crystalSymmetry('m-3m', 'color', 'light blue');

% specimen symmetry
% SS = symmetry('-1'); % -1 Triclinic
% SS = symmetry('2/m'); % 2/m monoclinic
SS = specimenSymmetry('-1'); % mmm Orthorombic

% plotting convention
setMTEXpref('xAxisDirection','north'); %north
setMTEXpref('zAxisDirection','outOFplane');

%% Specify File Names

% path to files

pname = 'C:\Users\ItaloP\Desktop\example1';

% which files to be imported

fname = [pname '\TEX_PH1.t1'];

%% Import the Data Simplified


% create an EBSD variable containing the data
odf = loadODF(fname,CS,SS);

v1=vector3d(0,0,1);


m1=Miller(0,0,1,CS);
m2=Miller(1,1,0,CS);
m3=Miller(1,1,1,CS);

h=[m1,m2,m3];

plotIPDF(odf,v1,'antipodal','contour')
annotate(h,'all','labeled')
colorbar

The problem is that the inverse plot figure that I should get is this one (from the manual of the VPSC):

But I get this one instead:

As you can see, the maximum values are different (32 vs almost 4 in my plot). I don't know if I did something wrong or not. But I am stuck with this problem. Maybe it's a silly error, I don't know.
Another little question is why there are not labeled all the Miller index in my plot (the 1,1,0 is missing) and why my plot it's aligned vertically instead of horizontally.

I know that probably these questions can sound very silly, but as I told you I am new in this field.

Also, I would appreciate if you could give me some advice on where to find some material that could help me using MTEX.

Thanks in advance,
Italo

[Ralf Hielscher]

Hi Italo Persechino,

first doing setting the plotting convention x-axis to east by

plotx2east

before plotting should align you inverse pole figure as you want it.

With respect to you first question note that there is not a one-to-one relationship between ODFs and individual orientations as exported from VPSC. There is always some smoothing involved. You can control the smoothing by the options halfwidth. A smaller halfwidth results in a sharper ODF, while a larger halfwidth makes a weaker ODF. The syntax is

odf = loadODF(fname,CS,SS,'halfwidth',3*degree)

I hope this helps.

Ralf.

[Italo Persechino]

Thank you very much Ralf. I appreciate your reply.

I am currently using the 3.5.0 version of MTEX, which has different kernels for importing the ODF data (I didn't know this from the 4.0.9 version and honestly I still don't know what they means, but they works) and using the 'bump' kernel it works, at least it gives me back the same as VPSC.