Question

The following median grain size data were obtained during the isothermal liquid phase sintering of an 82W-8Mo-8Ni-2Fe alloy. (Time in minutes : Grain Size Micrometer), 30:6.0 , 120:13.4 , 480:21.3 , 960:31.6 What is the time dependance for grain growth in the system and what is the probable grain-coarsening mechanism? Ignore the initial grain size.

Answer 1

Following is the Table prepared with the given (i.e.. Time (minutes) vs. Grain Size (Mmicrometer) ) Data, provided in the problem ..(obtained using MS Excel)...in ...image format........

Data & Table:

Grain Size Time (minutes) (Micrometer) 30 120 480 fill 6 13.4 21.3 31.6

And, following the resulting plot of the data produced above....(obtained using MS Excel..)... in ...image format...

Time (min.) vs. Grain size(micrometer) 35 20 15 E 10 Time (min.) vs. Grain size(micrometer) Linear (Time (min.) vs. Grain size(micrometer)) 0 200 400 600 800 1000 1200 Time (minutes)

The above Plot shows the time dependence of grain growth, and the most probable grain-coarsening mechanism is Ideal Grain Growth (mechanism).

Explanation:

The Ideal Grain Growth follows the following principle....i.e.. (following):

d² - d_o² = kt

Where:

d_o = initial grain size

d = final grain size.

t = time spent after the start of grain size growth; (i.e. t = 0 )

k = temperature dependent constant.

   As we can see, from the set of given data.....the calculated value of k $\approx$ 1.2 (approx.)