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Analysis of Forging Cracks during Hot Compression of Powder Metallurgy Nickel‐Based Superalloy on Simulation and Experiment
Author(s) -
He Guoai,
Liu Feng,
Huang Lan,
Jiang Liang
Publication year - 2016
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201600270
Subject(s) - superalloy , materials science , forging , metallurgy , powder metallurgy , nickel , compression (physics) , microstructure , composite material
Hot compression tests on a newly designed hot extrusion Nickel‐based powder metallurgy superalloy are conducted at various deformation conditions. The contact friction coefficient ( f ) between the die and forged part is determined as 0.30–0.40 by analyzing the results of simulation and the real experiment. A new coefficient B is introduced to evaluate the bulging levels and relate the value of f . The critical strains to prevent peripheral cracks are found to relate closely to the processing parameters. Thermally induced porosity and MC type carbides of grain boundaries are the primary mechanism for inducing cracks. Examinations on microstructure of cracking demonstrate that the cracks propagate along grain boundaries. A model is proposed to illustrate the formation of fractures during hot forging.