溶液燃烧法制备Mo–La_(2)O_(3)纳米粉体及烧结性能的研究

Study on the sintering properties of Mo-La_(2)O_(3) nano-powders prepared by solution combustion method

利用溶液燃烧法制备氧化镧(La_(2)O_(3))掺杂Mo粉前驱体,对前驱体粉末还原、烧结,研究La_(2)O_(3)掺杂量(质量分数)对Mo–La_(2)O_(3)合金性能的影响。结果表明,前驱体粉末在700℃下氢气气氛中还原,得到平均晶粒尺寸在100~220 nm的La_(2)O_(3)掺杂Mo粉。Mo–La_(2)O_(3)粉末经过1600℃放电等离子烧结后相对密度达95%以上,但随着La_(2)O_(3)掺杂量的提升,其相对密度逐渐降低。随着La_(2)O_(3)掺杂量的增加(质量分数在0~1.0%范围内),显微硬度先上升后下降。在La_(2)O_(3)掺杂量为0.7%时,Mo晶粒尺寸为500 nm左右,材料显微硬度最高,达到了HV_(0.2)564。

Molybdenum(Mo)precursor powders doped by lanthanum oxides(La_(2)O_(3))were prepared by the ultra-rapid solution combustion synthesis method using the low-cost and non-toxic starting materials,and the precursor powders were reduced and sintered.The effect of La_(2)O_(3) doping content(mass fraction)on the properties of Mo–La_(2)O_(3) alloys was studied.The results show that,the La_(2)O_(3) doped molybdenum powders with the average particle size of 100~220 nm are obtained by the reduction of the combustion precursor in the hydrogen atmosphere at 700℃.The relative density of La_(2)O_(3) doped molybdenum alloys sintered at 1600℃is over 95%.With the increase of La_(2)O_(3) doping content(mass fraction in the range of 0~1.0%),the microhardness increases firstly and then decreases.When the La_(2)O_(3) doping content is 0.7%,the grain size of Mo is about 500 nm,and the microhardness of the materials reaches the highest as HV_(0.2)564.