胡本芙
,
李慧英
,
章守华
,
毛健
,
周瑞发
金属学报
在热等静压之前对Rene95合金粉末采用高温预热处理。试验结果表明,预热处理既可使粉末颗粒微观组织更加均匀化,又可使亚稳碳化物MC′发生分解和转变,重新析出二次MC+?和生成M_(23)C_6碳化物。明显改变碳化物的稳定性和分布状态,有效地抑制PPB的形成。
关键词:
高温合金
,
carbide
,
powder metallurgy
,
heat treatment
毛健
,
杨万宏
,
汪武祥
,
邹金文
,
周瑞发
金属学报
研究了Rene95粉末高温合金原始颗粒边界(PPB)析出相的形貌和分布状态,及其对As—HIP合金力学性能、断口形貌和微观断裂特性的影响,原始颗粒边界密集分布的析出相质点会导致颗粒间结合界面的脆化,降低塑性,断裂沿颗粒的球面进行增大析出质点的间距,可改善合金的界面结合强度,提高HIP合金的高温塑性、持久寿命,断裂变为穿颗粒进行
关键词:
Rene95
,
superalloy
,
powder metallurgy
,
particle boundary
,
fracture
陈礼清
,
吕毓雄
,
毕敬
金属学报
研究了粉末冶金法制备的SiCp增强铝基（Al—3．OCu—1．5Mg—0．4Mn）复合板材在热轧和冷轧状态下的力学性能及板材中的晶粒取向分布结果表明，热轧板材抗拉强度及塑性明显高于冷轧态，屈服强度则低于冷轧态.冷轧板织构主要包含微弱的剪切织构{001}<110>和两个常见的面心立方金属织构组分{110}<112>及{3314}<773>；而热轧板织构近乎无规分布.晶粒取向的择优对复合板材的屈服强度有一定影响，与抗拉强度无关.冷轧板抗拉强度的降低是轧制时产生的大量做裂纹所致．
关键词:
金属基复合材料
,
powder metallurgy
,
mechanical property
,
texture
赵占奎
,
姚可夫
,
李建忱
,
蒋青
金属学报
用快速凝固/粉末冶金法, 制备了致密超高强度块体
Al90Mn8Ce2合金, 其尺寸为直径20 mm、长10 mm.
合金的致密度大于99%, 合金抗压强度达到895 MPa, 压延塑性超过6%. 合金获得超高强度主要是由于亚稳态二十面体准晶相在803 K和1.2 GPa条件下仍稳定存在, 对α--Al基体起强化作用.
关键词:
超高强度
,
Al--base alloy
,
powder metallurgy
HU Benfu LI Huiying WU Chengjian ZHANG Shouhua University of Science and Technology Beijing
,
Beijing
,
China Associate Professor
,
Dept.of Material Science and Engineering
,
University of Science and technology Beijing
,
Beijing 100083
,
China.
金属学报(英文版)
The solidification microstructure and phase composition of Ni-base superalloy FGH95 pow- der with different mesh size have been investigated.The structure transition was found from dendrite in major into cellular structure as the powder size reduces and the cooling rate in- creases.The predominant phase was identified as MC-type carbide,with different morphologies,which may be related to their composition and the condition of solidification.Minor phases,such as boride,Laves and primary γ' are also present as ac- companiments of the carbide.
关键词:
powder metallurgy
,
null
,
null
,
null
Q. Li
,
K.C. Chou
,
K.D. Xu
,
null
,
null
,
null
金属学报(英文版)
A new model to study the hydriding/dehydriding (H/D) kinetic mechanism has been applied in the two-phase (α-β) region of the Mg-6mol%LaNi composite at temperature and pressure ranging from 523 to 623K and 0.256 to 0.992MPa H2, respectively. The coincidence of the theoretical calculation with the experimental data indicates that the rate-limiting step is hydrogen diffusion in the β phase for hydriding process and the diffusion of hydrogen in the α solid solution for hydrogen desorption with activation energies 89500 and 87900J/mol H2 for H/D processes, respectively, which were much smaller than those of MgH2 and can be attributed to the La and Ni additions.
关键词:
powder metallurgy
,
null
,
null
F.Y. Cao
,
J.F. Sun
,
C.S. Cui
金属学报(英文版)
A Computational Fluid Dynamics Software was used to calculate the atomizing gasfields generated by a self-designed atomizer and to analyze the effects of key atomizingvariables such as gas pressure and protrusion length of delivery tube on the gas flowstate at the tip of or inside the delivery tube. Increasing the length of delivery tube toa certain extent, the eddy flow region with positive pressure moves away from the tipof delivery tube, which is favorable to achieve the effective atomization of the melt.
关键词:
atomization
,
null
,
null
,
null
MAO Jian YANG Wanhong WANG Wuxiang ZOU Jinwen ZHOU Ruifa Beijing Institute of Aeronautical Materials
,
Beijing
,
China MAO Jian
,
senior engineer
,
Beijing Institute of Aeronautical Materials
,
Beijing 100095
,
China
金属学报(英文版)
Nature of PPB precipitation of P/M Rene'95 and its effects on mechanical properties,frac- ture morphology and microfracture characteristics are discussed.Dense PPB precipitates make the boundaries brittle and lower the plasticity of the alloy.Fracture path is along the boundaries of particles.As PPB parameter increases,the interfaces between particles are strengthened.The fracture mode is changed from interparticle to transparticle.As a result,the plasticity at high temperatures and stress rupture life of the alloy are improved.
关键词:
Rene'95
,
null
,
null
,
null
