STP1172: Use of the Chevron-Notched Short Bar Test to Guarantee Fracture Toughness for Lot Release in Aluminum Alloys

    Bray, JW
    Supervisor, Reynolds Metals Company, Metallurgy Laboratory, Richmond, VA

    Pages: 13    Published: Jan 1992


    Abstract

    Chevron-notched short bar fracture toughness (KIvM per ASTM E 1304) has been correlated with plane strain fracture toughness (KIc or KQ per ASTM E 399 or ASTM B 645) for commercial 2124-T851, 7050-T7451, 7050-T7651, and 7475-T7351 plate.

    It was found that the chevron-notched and KIc(KQ) test methods correlated regardless of alloy, orientation, or temper. However, larger scatter in the higher toughness materials resulted in expected retest rate advantages (% of time the correlative test would fail and the referee test would pass lot release) when separating the results into “low” and “high” toughness databases. An A value minimum approach, via computation of derived properties (as defined in paragraphs 9.2.10 and 9.2.11 of Military Handbook 5E), was used to calculate the lot release correlations between KIvM and KIc(KQ). In addition, statistical correlations were performed on the entire database in order to utilize the chevron-notched short bar test more effectively for research and development programs.

    Keywords:

    fracture toughness, chevron-notch short bar, fracture test invalidity, aluminum alloys, correlations, A, minimums, K, Ic, KQ, K, IvM, K, Iv, 2124, 7050, 7475, lot release


    Paper ID: STP24715S

    Committee/Subcommittee: E08.04

    DOI: 10.1520/STP24715S


    CrossRef ASTM International is a member of CrossRef.