X-Ray Observations on Side-Bands of a Cu-4wt%Ti Alloy

Abstract

The nature of side-bands from a Cu-4wt% Ti alloy aged at 250∼600°C have been examined in detail by using a Guinier type X-ray camera. The side-bands become more intense and sharper with progress of aging. During aging below 450°C, side-bands (termed the early stage side-bands) approach a main reflection line which remains at the same position as in the as-quenched state. Upon aging above 500°C, however, side-bands (the later stage side-bands) do not move any longer, but a main line shifts to a high angle side with increase of aging time t.
The features of the early stage side-bands are as follows: The quantity Q, which can be calculated from the angle distance Δθ between side-band and main line by using the formula Q=htanθ⁄(h²+k²+l²)·Δθ, increases proportionally to logt. The intensity of side-bands I increases with logt, and the halfwidth of side-bands W decreases. The relationships Q_h>Q_l, I_h>I_l and W_h<W_l are obtained. Here, the subscript h or l refers to the value for high or low angle side-bands, respectively. The ratio of Q_h⁄Q_l increases linearly with an increase in Q, and the W_h⁄W_l decreases, irrespectively of aging temperature. The ration of I_h⁄I_l increases linearly with Q at a rate which is higher at a lower temperature.