共搜索到196条信息,每页显示10条信息,共20页。用时:0小时0分0秒578毫秒
SR1>SR2>SR3>SR4. 关键词:镁合金;相场法;微观偏析;计算机模拟;密排六方结构 中图分类号:TG111.4 文献标志码:A Numerical simulation of microsegregation of magnesium alloys quantitatively using phase-field method YAO... is and the severer the microsegregation is. The relationships are >>>, >>>, δ1< δ2<δ3<δ4 and SR1>SR2>SR3>SR4, respectively. Key words: magnesium alloy; phase-field method; microsegregation; computer......
morphology is cellular or globular. The eutectic transformation L→α-Mg+β-Mg17Al12 and microsegregation in conventionally solidified AZ61A alloy are suppressed to a great extent. The β-Mg17Al12 phases located......
boundaries. The grain refinement effect occurs and it displays a morphological transition of "coarse dendrite-equiaxed grain" with the decrease of droplet diameters, meanwhile, the microsegregation......
Ⅰ,Ⅱ,Ⅲ和Ⅳ)内典型合金的凝固路径 Fig. 1 Nb-Ti-Co phase diagram in Nb-rich region calculated by using microsegregation model coupled with Thermo-Calc and calculated solidification paths for typical alloys in four... software, and then the solidification paths of 58 kinds of alloys were studied by using the uniform microsegregation model. The influences of solid back diffusion coefficient and solidification rate......
BFe10-1-1合金管材连续定向凝固制备工艺及组织力学性能甘春雷1,刘雪峰1,黄海友1,谢建新1(1.北京市北京科技大学材料先进制备技术教育部重点实验室)摘 要:采用真空熔炼,Ar气保护下拉式连续定向凝固方法制备了BFe10-1-1合金管材,确定了可获得表面光洁合金管材的工艺参数范围,并对不同制备工艺下合金管材的组织和力学性能进行了研究.结果表明,当冷却水流量,冷却距离和冷却水温度保持不变(分别为900 L/h,8 mm,25℃)时,在熔体温度1250-1280℃和下拉速度0.15-0.45 mm/s的范围内......
板坯连铸结晶器内钢凝固过程热行为研究 Ⅰ.数学模型蔡兆镇1,朱苗勇1(1.辽宁省沈阳市东北大学材料与冶金学院)摘 要:建立了伴随δ/γ相变的钢凝固过程两相区溶质微观偏析模型,以其所确立的钢凝固过程各相分数与温度之间的关系获得钢的高温物性参数,并根据连铸坯在结晶器内凝固收缩量与结晶器内表面的位移关系,保护渣的液/固状态及厚度分布,铸坯表面和铜板热面的温度分布以及气隙的动态变化等建立了描述坯壳-铜板界面热流的数学模型.在此基础上,运用率相关本构模型,采用顺序耦合法建立了描述板坯连铸结晶器内钢凝固过程热行为的二维瞬态......
] and ZHENG et al [4] studied the morphologies and microsegregation of directionally solidified Mg-4Al alloy and AX44 (Mg-4Al-4Ca, mass fraction, %) alloy using electron probe microanalysis (EPMA) and the Scheil-solidification model. PETTERSEN et al [5] studied dendrite crystallography of directionally solidified AZ91 magnesium alloy. MIRKOVIC et al [6] analyzed the microsegregation......
samples 4 Discussion A dynamic diffusion process is brought during the homogenization, as source of microsegregation on the interdendritic zones. It can produce a short-range order in the aluminium... A8006 alloys, TRC process is beneficial for the less microsegregation, the improvement on the microstructure of as TRC processed A8006 alloy and the formability of the aluminium sheet as well. Hence......
]. As is well known, the microsegregation of main elements is inevitable for 7xxx aluminum alloy during casting, and massive undissolved secondary phases occur in the ingot. The constituent phases, such as η... alloy ingots before plastic processing. It plays a key role in dissolving large soluble non-equilibrium intermetallic phases and eliminating the microsegregation in the matrix [10-12]. Intermetallic......
. 1(b)). The first microsegregation is the flower-like phase (Phase A) within the interdendritic regions. It is the typical γ/γ′ eutectic (γ/γ′-segregation, TaAl-rich, Fig. 2(a)) as is usually observed...). The second microsegregation (Phase B) is a small amount of black regions within the interdendritic regions, surrounded by gray regions consisting of the γ+γ′ microstructure (Fig. 1(b)). The black......