Abstract: The invention provides a copper alloy strip, wherein the copper alloy comprises the following components in percentage by mass: 0.1 wt %-1.0 wt % of Cr, 0.01 wt %-0.2 wt % of Si, 0.01 wt %-1.0 wt % of X and the balance of Cu and inevitable impurities, wherein X is at least one of Fe, Ti, 5 Zr, Ag, Zn and Sn; on a section of the copper alloy strip perpendicular to a rolling direction, the number of second-phase particles having a particle size of 5 nm or below 5 nm is A, the number of second-phase particles having a particle size of 100 nm or above 100 nm is B, and A/B is greater than or equal to 3.

Abstract: A method includes simplifying flowing of airflow at root of a rotor blade into flowing of free jet, and determining an airflow expansion angle according to Mach number of incoming flow at root of a stator vane; calculating a radial height difference between a first end point on a leading edge of a stator platform and a trailing edge of an adjacent rotor platform by using an axial distance thereof, the angle and a deviation coefficient; determining position of the first end point with radial height difference; determining intersection point of the leading edge and the stator platform as position of a second end point on the leading edge; and determining a profile line between the points by bridging spline curves, so that the tail end thereof is tangent to the intersection line, and the starting end thereof is kept on same plane as side wall of the leading edge.

Abstract: A blade platform, comprising a pair of side edges and a pair of bottom edges, wherein the side edge comprises a linear portion and a curved portion, wherein the linear portion comprises a first linear portion and a second linear portion, and the curved portion comprises a first curved portion and a second curved portion; wherein the first linear portion and the second linear portion are connected to two ends of the curved portion and are tangent to the curved portion, slopes of the first curved portion and the second curved portion are in the same direction and the first curved portion and the second curved portion are circumscribed. The benefits of the blade platform are that the problems of platforms pushing against each other and get stuck during the working state as in the prior art or lack of accuracy in the test results of the blade circumferential clearance test and the dynamic balance test can be avoided.