烧结气氛对17Ni/(10NiO-NiFe_2O_4)金属陶瓷物相组成及力学性能的影响

Effect of sintering atmosphere on phase composition and mechanical properties of 17Ni/(10NiO-NiFe_2O_4) cermet

采用冷压-烧结法在不同的烧结气氛下制备17Ni/(10NiO-NiFe2O4)金属陶瓷,并研究材料的物相组成、显微结构及力学性能。研究结果表明:在低真空及氧体积分数分别为2×10-5,2×10-4,2×10-3和1×10-2的气氛中均可获得17Ni/(10NiO-NiFe2O4)金属陶瓷,但气氛中氧体积分数对各组成物相的质量分数影响较大,在低氧体积分数时NiO含量相对较高,高氧质量分数时金属相质量分数相对较高;当烧结气氛中氧体积分数为2×10-4时,可获得晶粒尺寸为2.477μm的17Ni/(10NiO-NiFe2O4)金属陶瓷,其抗弯强度可达116.55 MPa,在960℃下抗热震循环数可达7次,具有较好的力学性能。

17Ni/（10NiO-NiFe2O4） cermet materials were fabricated by cold pressing sintering method in different atmospheres,and their phase composition,microstructure and mechanical properties were also studied.The results show that 17Ni/（10NiO-NiFe2O4） cermet can be obtained by sintering in low vacuum or atmosphere with oxygen content（volume fraction） of 2×10-5,2×10-4,2×10-3 and 1×10-2,and the oxygen content affects on the phase composition of materials greatly.Cermet tends to have a high content of NiO sintered in atmosphere with low oxygen content,and a high content of metallic phase sintered in atmosphere with high content of oxygen.When the oxygen content of atmosphere amounts is 2×10-4,the grain size of 17Ni/（10NiO-NiFe2O4） cermet is 2.477 μm,and bending strength is 116.55 MPa,which can withstand 7 times of thermal shock tests at 960 ℃.