Appeal 2007-2359
Application 90/006,951
The Rejections
85. The Examiner finds that Reiso teaches cast aluminum ingots having
all limitations of claims 1–5, 7–13, and 15-20 but for:
(1) the use of Mn in the claimed amount together with excess Si;
(2) homogenizing the ingot to convert β-AlFeSi to α-AlFeSi; and
(3) thermally aging the ingot at a heating rate of 10 to 100°C per hour
(required by claims 9 and 15).
(Answer at 6 and 8.)
86. In particular, the Examiner finds that alloys 6 and 16 are compositions
meeting the Mg, Si, and Fe limitations of Alcan's claims, including the
Mg2Si and excess Si amounts (required by claim 3). (Answer at 5.)
87. The Examiner finds that Reiso teaches that coarse Mg-Si phases may
be avoided and the extrudability improved in the AlMgSi alloys by adding
small amounts of dispersoids such as 0.06% Mn. (Answer at 6.)
88. The Examiner reasons that it would have been obvious to include 0.06
wt% Mn in alloys 6 and 16 to improve the extrudability, as taught by Reiso.
(Answer at 6.)
89. The Examiner finds that EP and WO teach homogenization to convert
β-AlFeSi to α-AlFeSi and thermal aging at the required heating rate to
develop the required strength properties. (Answer at 7.)
90. The Examiner also finds that EP and WO teach that Mn is added to
improve extrusion surface quality, and that it accelerates the β- to α-AlFeSi
transformation. (Answer at 7.)
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