As we all know, the slip in bcc metals always involves glide in the direction of type, but the slip plane may be any of {110},{112} or {123}. The slip systems in bcc crystals also depend on the temperature, strain rate or other environmental factors. Here my question is : is it possible for one plane containing direction,such as (134), to be the slip plane in bcc metals during the deformation at room temperature with a low strain rate(employed during the static deformation)?
Hi Chuanyun,
I don´t think that (134) plane can be used for slip. The slip is realized on the planes with the highest atomic density. If these preferential planes are inappropriately oriented to direction of applied stress and reached Schmid factor on these planes is low, then we can consider about planes with next lower atomic density. In such an case you need higher applied stress. However, in BCC crystal we can find 24 or 48 (it depends on chemical composition and temperature) slip system combinations, so there are many orientation possibilities how to find one of them.
@ Vladimir Girman, Thank you for your reply. I just take the (134) as one example in the question description. As we all know, there is no close packed plane in bcc crystal but close packed direction , which results in 48 potential slip systems. However, I think it may be too arbitrary to determine the activated system by just calculating the Schmidt factor (SF) and accepting the one can be related to SFmax within these 48 ones. We also need to confirm it by connecting the very slip system to traces left on sample to guarantee the results are reliable. I have checked the potential slip systems in literature and found this table attached (Courtney TH, Mechanical behavior of materials, McGraw-Hill Companies, Inc. 2000 p160). From the note the authors seems try to tell us that not only {110},{112} and {123} but also other planes containing can be slip plane as well. What's your opinion on this?
As far as I understand the concept of packing you do not have a closed-packed plane in bcc but a close packed plane which is the {110}. If you look for phase transformations they say that the closed-packed {111}fcc usually transform into the close-packed plane {110}bcc. And if you look for the density, both phases fcc and bcc do not show a very different density. Look e.g. the discussion at the attached link...
https://www.researchgate.net/post/Why_is_the_density_of_the_closed-packed_austenite_lower_than_of_the_body-centered_ferrite
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