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1.
陈渭臣 《铸造》1998,(3):33-35,41
系统对比了加Te及加Sr或三元钠盐对ZL104处理后所浇注金属型试棒(经T6处理)的力学性能,结果表明,Te的合金力学性能略低于Sr自理的,而略高于三元钠变质的;Te处理的合金具有长效性,熔体保温8h或3次重熔、每次保持6h,其效果不变,长效性超过Sr变质;Te处理的合金的伸长率较Sr处理的高40-50%,较三元钠盐处理的高1倍。  相似文献   

2.
Al—Sr中间合金变质效果的遗传效应   总被引:15,自引:0,他引:15  
通过不同铸工艺制取的相同成要不同形貌的变质用Al-8.62%Sr中间合金,具有明显的变质效果差异。在砂型条件下,用Al-8.62%Sr中间合金对共晶Al-Sr合金进行变质处理,加入使Al-Sr合金含0.1%Sr的锭料和加入使Al-Sr合金含0.05%Sr的激冷薄片,二者的变质效果相当,都为5级。在金属型条件下,加入使Al-Sr合金含0.06%Sr锭料和加入使Al-Si合金含0.03%Sr的激冷薄片  相似文献   

3.
李德成  张照文 《铸造》1994,(11):18-20
用0.03~0.08%Sr对ZAlSi7Mg1A合金进行变质,其变质工艺为:先用C2Cl6除气,静置扒渣后加Sr,并同时通氩气,其流量为3~6L/min,直至出炉浇注。该工艺可保证合金变质良好、无气,合金的综合性能较Na变质有提高。  相似文献   

4.
锶-稀土长效变质剂的应用   总被引:1,自引:0,他引:1  
研究了铝-锶-稀土合金对铝硅合金中的共晶硅及亚共晶硅的细化变质作用,该变质剂变质时间可保持4小时以上不衰退,同时还具有除气和净化铝液的功能,克服了单独用锶变质时吸气及不能同时用氯化物精炼等问题,并发现了Sr与RE在变质过程中有协同效应。  相似文献   

5.
锶—稀土长效变质剂的应用   总被引:1,自引:0,他引:1  
张淑芬  蒙进 《铸造》1994,(11):33-35
研究了铝-锶-稀土合金对铝硅合金中的共晶硅及亚共晶硅的细化变质作用,该变质剂变质时间可保持4小时以上下衰退,同时还具有除气和净化铝液的功能,克服了单独用锶变质时吸气及不能同时用氯化物精炼等问题,并发现了Sr与RE在变质过程中有协同效应。  相似文献   

6.
合金元素对Zr-Sn-Fe-Cr-Nb合金性能的影响   总被引:1,自引:0,他引:1  
介绍了几种新锆合金400℃,10.3MPa静态高压釜试验结果和室温及高温(375℃)的拉伸试验结果,分析了新合金中合金元素Nb.Sn.Fe.Cr对抗伸强度及耐蚀性能的影响。结果表明:通过控制合金元素的含量,在经历与Zr-4相同的生产工艺条件下、可以得到强度和耐蚀性能更为优异的新铝合金。试验表明:这种新型的Zr-Sn-Fe-Cr-Nb中加入Nb量应在0.1wt%-0.3wt%之间;在含1wt%Nb的新合金中,Sn的含量不应低于0.5wt%:在新合金研制时,适当提高Fe+Cr的含量是有益的,但Fe/Cr比不应太高。  相似文献   

7.
镁对锑变质激化作用的研究   总被引:6,自引:2,他引:4  
研究了铸造铝硅合金中镁对锑变质作用的影响。结果表明,在一定范围内,加入锑后再加入镁,其变质能力激剧增强。文中所示锑、镁含量与力学性能关系表明,对于共晶合金,含(质量分数)02%Sb、06%Mg时合金的综合力学性能最高。还就镁对锑的激化机制做了初步分析。  相似文献   

8.
快速凝固Al-Sr中间合金及其变质效果   总被引:3,自引:0,他引:3  
快速凝固使Al-Sr合金产生了微观组织细化、缺陷密度增加、成分均匀化以及固溶体过饱和化等变化。在Al-Sr合金快速凝固条带(以下称激冷带)横截面上出现“双区”组织。冷却速度达到106K/s激冷带的激冷侧晶粒达到纳米级。变质实验结果表明:不同冷却速度下形成的Al-Sr中间合金具有不同的变质效果,快速凝固的Al-Sr中间合金达到与常规Al-Sr中间合金相同的变质度,其用量减少50%~60%,潜伏期缩短50%左右。  相似文献   

9.
介绍了几种新锆合金400℃,10.3MPa静态高压釜试验结果和室温及高温(375℃)的拉伸试验结果,分析了新合金中合金元素Nb.Sn.Fe.Cr对抗伸强度及耐蚀性能的影响。结果表明:通过控制合金元素的含量,在经历与Zr-4相同的生产工艺条件下、可以得到强度和耐蚀性能更为优异的新铝合金。试验表明:这种新型的Zr-Sn-Fe-Cr-Nb中加入Nb量应在0.1wt%-0.3wt%之间;在含1wt%Nb的新合金中,Sn的含量不应低于0.5wt%:在新合金研制时,适当提高Fe+Cr的含量是有益的,但Fe/Cr比不应  相似文献   

10.
应用电镜及X线衍射技术,研究了高温下Ni_(75)Al_(16.6)Cr_(7.84)Zr_(0.45)B_(0.1)Mg_(0.01)合金晶界失效行为。经1180℃保温,由于偏聚晶界区Mg含量(at.-%)达15-19。同时Zr含量(at,-%)明显增大可达28-33;并观察到局部晶界共晶熔化现象。通过1000℃固溶及变温热循环处理,合金中晶内出现CrN相沉淀,沿晶界有Cr2(C,N)相析出。  相似文献   

11.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

12.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

13.
The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.  相似文献   

14.
On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes' collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.  相似文献   

15.
An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.  相似文献   

16.
A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.  相似文献   

17.
吴玉梅  熊晓云  靳蓉  孙敬民  杨林  罗晓星 《金属学报》2005,10(10):1100-1103
目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。  相似文献   

18.
On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.  相似文献   

19.
During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality of the slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, thereby controlling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle and partly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structure and angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower than that without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at the top surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial to the growth of equiaxed crystal and decreased element segregation.  相似文献   

20.
The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).  相似文献   

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