In this work, water cooling, air cooling (AC) and furnace cooling (FC) were applied to investigate the effect of cooling rate on microstructure evolution of primary γ′ in a newly designed Ni₃Al-based alloy. The results showed that nucleation rate of primary γ′ increased with increasing cooling rate. In addition, higher cooling rate shortened growth period of primary γ′, which made its morphology close to the initial precipitated γ′. For AC and FC specimens, due to the lower cooling rate, primary γ′ possessed longer growth period and its morphology was mainly due to the evolution of lattice misfit between γ and primary γ′. Meanwhile, growth of primary γ′ depended on lattice misfit distribution between its corner and edge area. Moreover, primary γ′ morphologies of sphere, cube and concave cube with tip corners were illustrated by considering interaction between elemental diffusion and elastic strain energy.

在这项工作中，采用水冷，空冷（AC）和炉冷（FC）来研究冷却速率对新设计的Ni ₃ Al基合金中初生γ '的组织演变的影响。结果表明，随着冷却速率的增加，初生γ ′的成核速率增加。另外，较高的冷却速率缩短了初生γ ′的生长周期，这使其形态接近于初始沉淀的γ ′。对于AC和FC样品，由于冷却速率较低，初生γ ′具有较长的生长期，其形态主要是由于γ和初生γ之间晶格失配的演化所致。'。同时，原生γ ′的生长取决于其角和边缘区域之间的晶格失配分布。此外，通过考虑元素扩散和弹性应变能之间的相互作用，说明了具有尖角的球体，立方和凹立方的主要γ '形态。