Table 3. Characteristics of Eutectic Silicon Particles


Alloy code


G2 G3


G12


Particle Area (µm2)


Av


17.07 9.10 7.44


SD


18.60 12.10


10.60


Particle Length (µm)


Av


8.16 4.87 4.33


SD


6.68 4.12 3.73


Roundness Ratio (%)


Av


39.97 51.60 60.00


SD


20.83 20.90 18.90


Av


2.76 2.02 2.07


Table 4. Total Number of Holes Drilled and Total Number of Samples Drilled for Each Alloy Drill


G2 396 + 0.15%Sn


Holes drilled


Solid Carbide


Special Solid Carbide Cobalt Grade


High Precision Solid Carbide


1,980 1,809* 2,016 2,016


Samples drilled


14


12.56* 14 14


Holes drilled


971*


1,728 1,728 1,728


G3 396+ 0.25%Fe + 0.25%Mn


Samples drilled


6.74* 12 12 12


Note: The values marked with an asterisk (*) indicate that it was a case of the drill breaking


T e only drills aff ected were the special solid carbide drill when used with the 396-G2 alloy and the solid carbide drill when used with the 396-G3 alloy. On the other hand, the 396-G3 al-


loy, which contains sludge intermetal- lic particles, was more sensitive to tool wear than the 396-G2 and B319.2-


G12 alloys. In this case, the maximum number of holes drilled was 1,728, with the exception of the solid carbide drill that broke down after 971 holes. T e sludge phase—which has a


high hardness value, high melting point and high specifi c gravity com- pared to the matrix—is clearly capable


of damaging cutting tools. T e sludge phase may cause rapid tool wear and introduce problems accompanying a dull tool, which was confi rmed upon drill wear examination. 


T is article is based on a paper (12-079) published in AFS Transactions 2012.


Holes drilled


2,000 2,016 2,016 2,016


Aspect Ratio


SD


1.65 1.06 1.05


41,071 67,114


12,000 Density (particles/mm2)


G12 B319.2 + 0.15%Sn


Samples drilled 14


14 14 14


Sept/Oct 2013 | METAL CASTING DESIGN & PURCHASING | 45


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