Heat affected zone liquation cracking in electron beam welded third generation nickel base superalloys

Atomic-scale grain boundary engineering to overcome hot-cracking in additively-manufactured superalloys

“…the shrinkage effect, as well as thermal stresses caused by rapid cooling provide the mechanical driving forces for the development of hot cracks [38]. These local thermal stresses combined with segregation-driven grain boundary liquation cause hot cracking [39,40]. The building history of the cracked columnar sample that leads to cracking is summarised in the schematic in Figure 12.…”

An investigation about the effect of annealing conditions on microstructure in a Ni3Al base alloy

“…2, the ␥ − ␥ eutectic in this alloy is a non-equilibrium structure. Non-equilibrium ␥ − ␥ eutectic is seen on some of the Ni base super alloys like Rene-80 [16], IN-738 [17], EP 962 [18], TMS-75 and TMS-75+C [19]. These alloys contain between 3 and 6 wt.% of aluminum.…”

An analytical algorithm to predict weldability of precipitation-strengthened nickel-base superalloys

“…␥ , ı, ␥-NbC, ␥-Laves) can strongly deteriorate the alloy weldability (i.e., resistance to hot cracking). Ojo et al (2008) have presented that Ti and Al in the nickel-based alloys strengthened with ␥ -Ni 3 (Ti,Al) such as Inconel 738, Udimet, Waspaloy and Rene, have high tendency to segregate to the terminal liquid of weld metal or dissolve in the nickel austenite, or to form intermetallic and carbide constituents such as ␥ , ␥-TiC, ␥-␥ eutectics that cause challenges of hot cracking in the weld metal and HAZ. Moreover, increasing in the total amount of Ti + Al promotes the weld to strain-age cracking.…”