greater for the component engine block casting than for the same parameters studied in the wedge casting, would the component casting be sufficient for analysis? With current engine designs and future engine programs having thinner wall thicknesses, and even more complex geometries, it is difficult to extract mechanical test samples from areas other than the bulkhead or bolt boss sections. These casting


80


75 70 65 60 55 50 45 40 35 30 25 20


0 5 10 15 20 Sample Number


Figure 21. The staircase plot for the W319 alloy. The average of the failed tests (above) is used to determine the reported average along with the standard deviation.


25 30 35


sections may have microstructures which are different and thus critical data such as yield stress will not be known for stress analysis software used in the design stage.


However, the wedge casting made in tandem to a com- ponent engine block casting may provide critical infor- mation needed for a successful alloy conversion inves-


Figure 22. The mean fatigue stress and -3σ as established using the staircase method from the CEB bulkhead section.


International Journal of Metalcasting/Fall 10 47


Fully Reversed Stress (MPa) (R=-1, Operating Temperature = 120 °C)


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