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I am seeking expert explanation to a recent observation.  A crack was observed in a Cu-Zn brass part of roughly 60/40 with lead addition.  Crack was parallel to the rolling direction of the bar which the part is made of. The crack surface has the brittle fibrous appearance and some elongated but fragmented red color constituents were observed.  They are not copper rich as one expected in case of dezincification.  Rather they are Zn rich, some even is close to the chemistry of Gamma phase per Cu-Zn phase diagram.  Normally, this alloy should be alpha base with small quantity beta phase.  I would like to know what the color of gamma phase is in a Cu-Zn alloy.  Is what I see really gamma phase and why it is present.  I would appreciate any help hints and insights.

@Derek Tyler might be able to help. I will also report this to the FAS online community to see if you get a response there.

I am seeking expert explanation to a recent observation.  A crack was observed in a Cu-Zn brass part of roughly 60/40 with lead addition.  Crack was parallel to the rolling direction of the bar which the part is made of. The crack surface has the brittle fibrous appearance and some elongated but fragmented red color constituents were observed.  They are not copper rich as one expected in case of dezincification.  Rather they are Zn rich, some even is close to the chemistry of Gamma phase per Cu-Zn phase diagram.  Normally, this alloy should be alpha base with small quantity beta phase.  I would like to know what the color of gamma phase is in a Cu-Zn alloy.  Is what I see really gamma phase and why it is present.  I would appreciate any help hints and insights.

@Derek Tyler might be able to help. I will also report this to the FAS online community to see if you get a response there.

I am seeking expert explanation to a recent observation.  A crack was observed in a Cu-Zn brass part of roughly 60/40 with lead addition.  Crack was parallel to the rolling direction of the bar which the part is made of. The crack surface has the brittle fibrous appearance and some elongated but fragmented red color constituents were observed.  They are not copper rich as one expected in case of dezincification.  Rather they are Zn rich, some even is close to the chemistry of Gamma phase per Cu-Zn phase diagram.  Normally, this alloy should be alpha base with small quantity beta phase.  I would like to know what the color of gamma phase is in a Cu-Zn alloy.  Is what I see really gamma phase and why it is present.  I would appreciate any help hints and insights.