(中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 以海綿鈦為原料，采用經(jīng)過氫化破碎、阻止劑包覆、真空脫氫以及阻止劑脫除的方法制備超細(xì)鈦粉。采用TEM、SEM以及激光粒度測試等手段研究制備過程中工藝參數(shù)對鈦粉形貌、粒度及氧含量的影響，探討阻止劑的晶粒長大抑制機(jī)理。結(jié)果表明：海綿鈦在700 ℃、2 h滲氫后經(jīng)過球磨5 h，粉末中位徑(D50)達(dá)到2.61 μm，以NaCl為阻止劑對氫化粉末進(jìn)行包覆，經(jīng)630 ℃、2 h脫氫并脫除阻止劑后，制得的超細(xì)鈦粉呈不規(guī)則形狀，中位徑達(dá)6.16 μm，氧含量為0.89%(質(zhì)量分?jǐn)?shù))；阻止劑的引入造成鈦粉氧含量的微量增加；通過阻止劑包覆，在粉末顆粒表面形成厚度為5~10 nm的隔離層，阻礙了加熱過程中Ti顆粒表面的原子擴(kuò)散，從而阻止加熱脫氫過程中粉末顆粒的長大。
關(guān)鍵字: 超細(xì)鈦粉；氫化脫氫；阻止劑；NaCl；顆粒長大
NaCl coated/hydrogenation-dehydrogenation combined method
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Ultrafine Ti powder was prepared through the process of hydrogenation, mechanical pulverization, inhibitor coated, vacuum dehydrogenation and inhibitor removed with titanium sponge as its raw materials. The effects of technological parameters on the morphology, particle sizes and oxygen content of Ti powders were investigated by transmission electron microscopy, scanning electron microscopy and laser-diffraction diameter tester, etc. The mechanism of NaCl inhibitory action was explored. The results show that the titanium hydride powder with D50 of 2.61 μm is obtained after the hydrogenation at 700 ℃ for 2 h and then mechanical pulverization for 5 h. Using NaCl as inhibitor to coat the titanium hydride powder, dehydrogenizing at 630 ℃ for 2 h and removing NaCl, an irregular Ti powder with D50 of 6.16 μm and oxygen content of 0.89% (mass fraction) is prepared. There is not a noticeable increase of oxygen content in the Ti powder after the addition of NaCl. The growth of Ti particles during the dehydrogenation is effectively inhibited through the coating treatment of NaCl which forms isolation layer of 5−10 nm thickness on the surface of Ti particles to the block surface atomic diffusion.
Key words: ultrafine Ti powder; hydrogenation-dehydrogenation; inhibitor; NaCl; particle growth
