Metal treatment – Stock – Directionally solidified
Patent
1981-12-14
1986-08-12
Dean, R.
Metal treatment
Stock
Directionally solidified
148410, 148428, 1641222, C22C 1905
Patent
active
046054529
ABSTRACT:
Alignment of the [001] crystal axis of a face centered cubic metal with the primary z axis of a single crystal article provides good thermal fatigue resistance along the z axis, and minimizes cracking transverse to the axis. However, significant cracking is still observed parallel the z axis in severe applications. This cracking can be reduced by controlling the secondary crystallographic orientation (i.e., orientation of crystal axes within x-y planes transverse to the z axis), to make the [110] crystal axis tangent to the article surface in the region most prone to thermal fatigue cracking. Algorithims derived from empirical relationships enable calculation of the orientation likely to produce improved fatigue resistance. More durable single crystal gas turbine blades result when the [110] crystal axis is made tangent to the blade surface in the critical crack prone regions just behind the leading edge of the airfoil at about 40-80% of the airfoil span. A representative improved gas turbine blade will have a secondary orientation angle .alpha. of -10 to +20 degrees, where .alpha. is the angle between the [100] crystal axis and the y axis.
REFERENCES:
patent: 3580324 (1971-05-01), Copley et al.
patent: 3598169 (1971-08-01), Copley et al.
patent: 3738416 (1973-06-01), Kear et al.
patent: 3857436 (1974-12-01), Petrov et al.
patent: 3915761 (1972-05-01), Tschinkel et al.
Kear et al., "Tensile and Creep Properties of Single Crystal . . . " Trans. AIME, vol. 239, pp. 1209-1215, (1967).
Rau, Jr. et al., "Thermal-Mechanical Fatigue . . . " STP 520 ASTM (1973).
Gemma et al., "Thermomechanical Fatigue Crack Propagation . . . Anisotropic Superalloy" STP 612 ASTM (1977).
Wright et al., "The Influence of Orientation on Fatigue . . . " Materials Technology, pp. 31-35, (Spring 1981).
Dierberger James A.
Gemma Anthony E.
Dean R.
Nessler C. G.
United Technologies Corporation
LandOfFree
Single crystal articles having controlled secondary crystallogra does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Single crystal articles having controlled secondary crystallogra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Single crystal articles having controlled secondary crystallogra will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1934510