This page contains a Flash digital edition of a book.
The 1010 0.1% RE silicide and 1010 0.2% misch metal samples contained a larger number of inclusions that were either not surrounded by another oxide or were only par- tially surrounded by another type of oxide. These encap- sulating oxides were usually not high in RE. It is therefore likely that these slag coatings prevented the RE oxides that formed from acting as heterogeneous nuclei. This would explain the lower refinement and properties than the other samples.


The RE containing inclusions in the 1030 0.1% RE sili- cide sample appeared similar to some of the inclusions in the 1010 samples (Figure 24). At the gray center, the inclusions primarily consisted of a high RE content oxide with around 11% aluminum. Frequently, an iron-alumi- num oxide partially surrounded these inclusions. Some- times, these outer oxides contained significant levels of RE. The dark region surrounding the oxides in Figure 24 contained 10% RE.


Iron-aluminum oxides almost always encased the RE oxide inclusions in the 1030 0.2% RE silicide sample (Figure 25).


The light gray inner portion usually contained a significant amount of RE and approximately 19% aluminum, while the dark outer encapsulating phase contained 13% RE elements.


Like the previous two samples, the RE inclusions had a gray inner region that was a RE rich oxide (Figure 26). These RE oxides contained around 10% aluminum. The outer dark region usually was an iron-aluminum oxide. However, in a few inclusions, this was an iron oxide with minor amounts of aluminum and RE elements. The encap- sulating aluminum-iron or iron oxide did not fully surround all the RE oxides observed.


The 1030 0.2% misch metal addition sample contained RE inclusions similar to those observed in the previous samples. The gray center of these inclusions was usually a RE oxide (Figure 27). These oxides were frequently enveloped with a dark region of aluminum-iron or iron oxide. Not all of the inclusions were fully encapsulated, similar to the situation with the 1030 0.1% misch metal and 1030 0.1% RE silicide samples. All three of these samples had finer structures and higher yield strength than the baseline 1030 material.


Figure 22. Typical incusion for the 1010 0.1%MM sample.


Figure 24. Electron micrograph of the 1030 0.1% RS sample.


Figure 23. Electron micrograph of an inclusion in the 1010 0.2% MM sample


60


Figure 25. Typical inclusions for the 1030 0.2% RS sample. International Journal of Metalcasting/Spring 2012


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91