Composite sheet metal article

Claim 1

A COMPOSITE SHEET METAL ARTICLE COMPRISING: (A) A FIRST AND SECOND COMPONENT SHEET HAVING A PATTERN OF STOP WELD MAERIAL THEREBETWEEN, SAID SHEETS BEING INTEGRALLY UNIFIED EXCEPT IN THE AREA OF THE STOP WELD MATERIAL; (B) SAID FIRST COMPONENT SHEET CONSISTING ESSENTIALLY OF AN ALUMINUM BASE ALLOY WITH FE+SI 1.0% MAXIMUM AND AL 99.00% TO 99.75%, SAID SHEET HAVING A COARSE PARTICLE SIZE DISPERSION OF A-ALFESI AS AN ISOLUBLE INTERMETALLIC COMPOUND PRESENT THEREIN; (C) SAID SECOND COMPONENT SHEET CONSISTING ESSENTIALLY OF SUBSTANTIALLY THE SAME ALUMINUM BASE ALLOY AS THE FIRST COMPONENT SHEET AND HAVING A FINE PARTICLE SIZE DISPERSION OF SAID INSOLUBLE INTERMEDIATE COMPOUND PRESENT THEREIN; (D) SAID FIRST COMPONENT SHEET BEING RELATIVELY SOFT WITH YIELD STRENGTH VALUES IN THE ORDER OF 5,000 P.S.I. MINIMUM AND SAID SECOND OMPONENT SHEET BEING RELATIVELY HARD WITH YIELD STRENGTH VALUES IN THE ORDER OF 18,000 P.S.I. MAXIMUM, WITH DISTENSIONS RAISED FROM THE FIRST COMPONENT SHEET CORRESPONDING TO THE PATTERN OF STOP WELD MATERIALL.