抄録
Special observations on Al_2O_3 seeded P/M Rene95 superalloy were conducted at SEM in-situ tension loading stage to study the inclusion effect on crack initiation, propagation and fracture behavior of P/M nickel-base superalloy. Experimental results show that, during SEM in-situ tensile process cracks easily initiate at the ceramic inclusions even at very low stress level(lower than yield stress of P/M Rene95). Generally, the cracks nucleate at inclusion/matrix interfaces and easily propagate along the interfaces to the matrix. Sometimes cracks can also directly initiate inside inclusions and propagate in the inclusions till to break the cracked inclusions. Stress concentration field nearby inclusion and the effect of inclusion size and distribution on stress fields were calculated. A proposed model of the inclusion effect on crack and fracture behavior has been discussed in this paper.
