纯钛等温加热过程中再结晶晶粒生长行为

Grain growth behavior of recrystallization of pure titanium during isothermal heating

在650℃、保温10～50 min下对纯钛进行再结晶等温加热处理。保温开始阶段,晶粒尺寸增长速率较慢,由于热轧态下纯钛不同晶粒间晶格畸变能的较大差异,出现了晶粒竞争生长现象,保温初期晶粒尺寸差异明显,一些大晶粒内出现孪晶;在随后的加热过程中,由于晶体内高晶格畸变能,并伴孪生切变,晶粒生长过程中原子扩散速率逐步提高,晶粒增长速率增加,晶粒尺寸趋于均匀。进一步研究更长时间的再结晶加热过程发现:由于晶粒晶格畸变能及孪晶的消失,晶粒增长速率将会逐步降低。

Isothermal recrystallization heating at 650 ℃ for 10-50 min was applied to pure titanium.The results show that grain size grow slowly at intial stage of recrystallization.The apparent difference of lattice distortion energy among grains of the as-hot rolled titanium causes competitive growth of grains.There is an apparent difference of grain size.Twins appear in large grains.During subsequent heating,due to high lattice distortion energy together with twinning shear,diffusion rate of atoms increases and then leads to increase of grain growth rate,and then grain sizes are gradually uniform.For the longer-time recrystallization heating,the grain growth rate decreases.