姜文标
,
刘友鹏
,
舒光冀
金属学报
<正> 铝-石墨复合材料制造中的突出问题是铝液与石墨的润湿能力很差,为此大多在工艺上采取措施,如石墨表面喷涂Ti-B,Ni或Cu涂层,或采用流变铸造等。然而这些措施使得工艺复杂、成本提高,因而推广应用受到限制。为改善铝液与石墨的润湿能力,有必要深入研究铝液对石墨的润湿过程。国内外这方面报道甚少,而且所报道的结果差别较大。我们通过长时间的保温试验,仔细地研究了不同温度下铝液对石墨的润湿过程,发现了一些新的现象。
关键词:
铝—石墨复合材料
,
wetting
,
contact angle
,
interface
,
reaction
Ruihua HU
,
Montasser M.Dewidar
,
Hyo-Jin KIM
,
Jae-Kyoo LIM
,
null
材料科学技术（英文）
In order to improve the wear resistance of Ti-6Al-4V, different amounts of Si3N4 powder were added into the alloy powder and sintered at 1250℃. Porous titanium alloy with higher wear resistance was successfully fabricated. At sintering temperature, reaction took place and a new hard phase of Ti5Si3 formed. The mechanical properties of the fabricated alloys with different amounts of Si3N4 addition were investigated. The hardness of Ti-6Al-4V, which is the index of wear resistance, was increased by the addition of Si3N4. Amounts of Si3N4 addition have very significant influences on hardness and compressive strength. In present study, titanium alloy with 5 wt pct Si3N4 addition has 62% microhardness and 45% overall bulk hardness increase, respectively. In contrast, it has a 16.4% strength reduction. Wear resistance was evaluated by the weight loss during wear test. A new phase of Ti5Si3 was detected by electron probe microanalyzer (EPMA) and X-ray diffraction (XRD) method. The original Si3N4 decomposed during sintering and transformed into titanium silicide. Porous structure was achieved due to the sintering reaction.
关键词:
Ti-6Al-4V
,
alloy
,
Wear
,
Sintering
,
reaction
Kaijin HUANG
材料科学技术（英文）
The microstructure and wear behaviour of the thermite reaction coating produced by the hybrid laser cladding-remelting on AA7075 aluminum alloy for the systems of Al-CuO-SiO2, Al-Cr2O3-SiO2, Al-Fe2O3-SiO2, and Al-TiO2-SiO2 were studied. The results of the X-ray diffraction (XRD) analysis show that in all the four reaction coatings, α-Al2O3 and γ-Al2O3 phases were present at the top surface, together with various intermetallic phases, the corresponding reduced metal and Al phase in the fusion zone. Under the dry sliding condition, the wear resistance, in terms of weight loss, of the laser-clad specimens was considerably higher than that of the untreated specimen. The predominant wear mechanism of the former specimens was abrasive wear, while for the latter, it was the adhesive wear that prevailed.
关键词:
Laser cladding
,
cladding
,
thermite
,
reaction
,
aluminu
B.W. Zhang
,
B.W. Li
金属学报(英文版)
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.
关键词:
inclusion
,
null
,
null
,
null
刘贵民
,
李斌
,
闫涛
,
郑晓辉
,
丁华东
机械工程材料
以铜铝合金粉为原料,利用反应球磨并结合放电等离子烧结工艺制备了Al2O3/Cu复合材料,研究了球磨不同时间后合金粉的形貌、物相以及铝含量对复合材料组织与性能的影响.结果表明:铜铝合金粉球磨20 h后,生成了粒径为2～5 μm的类球状颗粒,Cu相衍射峰发生明显的宽化,在铜基体中原位生成了纳米α-Al2O3颗粒相;Al2O3颗粒的尺寸及其在基体中的分布与铝含量有关,随着铝含量增加,Al2O3颗粒逐渐长大、富集甚至团聚;复合材料的相对密度和导电率均随着铝含量的增加逐渐降低,显微硬度则逐渐升高;当铝的质量分数为0.7％时,复合材料具有最佳的综合性能.
关键词:
反应球磨
,
Al2O3/Cu复合材料
,
显微硬度
,
导电率
郭超峰
,
陈俊芳
,
符斯列
,
薛永奇
,
王燕
,
邵士运
,
赵益冉
材料导报
采用ECR等离子体辅助技术,融合化学气相沉积法,在450℃的相对低温条下于Si(100)衬底上生长出GaN薄膜.对样品进行了XRD、FT-IR和AFM表征,并在制备过程中采集到反应室中N_2-(CH_3)_3Ga等离子体的发射光谱.结果表明,所制备的多晶体GaN薄膜是由N_2-(CH_3)_3Ga等离子体中的活性成分通过复杂的反应生成的,其生长过程符合岛状生长机制.
关键词:
等离子体
,
化学气相沉积
,
GaN
,
反应
,
生长机制
许小静
,
曲选辉
,
罗远辉
稀有金属材料与工程
Li-B合金是一种性能优良的热电池用阳极材料,由于合成制备困难制约了它的应用.通过对合成过程中气氛、搅拌、温度控制、后处理等工艺进行有效改进,获得了300g/炉的制备规模,得出了本实验条件下制备Li-B合金的最佳工艺,所制备的合金均匀致密,放电性能达到国内先进水平.
关键词:
热电池
,
Li-B合金
,
阳极材料
,
制备工艺
