共查询到19条相似文献,搜索用时 187 毫秒
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用能谱、X射线衍射、X射线荧光光谱和金相等分析手段,研究了九连墩楚墓出土的战国青铜文物的铅锡焊料的基体和锈蚀产物、发现产物致密、均匀,主要由PbCO3、Pb和SnO2组成,整个埋藏环境相对密闭,总体呈中性,HCO3-浓度较高。这些因素共同作用,减缓了铅锡焊料的腐蚀,使用大部分青铜器完好地保存了下来。 相似文献
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在电子组装早期用得最多的焊料主要是锡和铅两种元素,尤其是质量百分比为w(Sn)63%和w(Pb)37%的共晶铅锡合金为多数电子产品所采用.大量使用的Sn/Pb合金焊料正是造成污染的重要来源之一.在制造和使用Sn/Pb焊料的过程中,由于熔化温度较高,有大量的铅蒸气逸出,将严重影响操作人员的身体健康.同时焊接互联的常见热疲劳失效与富铅相有关,期望在设计锡基无铅焊料中不含有铅相,从而改善力学性能,强化焊料.介绍了无铅焊料的基本要求、无铅焊料的研究现状、无铅焊料面临的问题:指出无铅焊料及焊接可靠性仍是工业界和学术界研究的热点问题. 相似文献
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以Ti、Ag金属粉末压坯做焊料,采用热压反应烧结连接工艺连接再结晶SiC陶瓷.当焊接温度为1030℃,接头抗弯强度最高达116.8 MPa,为母材强度的73.4%.显微分析表明:在焊料产物层与SiC陶瓷母材之间形成一个反应层,焊接温度的变化对反应层的厚度有明显影响;反应层主要由TiC、Ti5Si3和Ti3SiC2组成,且Ti3SiC2紧邻母材SiC,而TiC则靠近焊料产物层一侧.SEM分析表明:焊料产物层为黑白相间的复相区,白色相主要是AgTi,黑色相主要由Ti和AgTi3组成. 相似文献
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研究了Sn-3.5Ag-0.75Cu和Sn-0.75Cu焊料合金在NaCl-Na_2SO_4-Na_2CO_3模拟土壤溶液中的腐蚀浸出行为,并与Sn-37Pb焊料合金的腐蚀浸出行为对比分析。研究表明,这3种焊料合金中Sn的浸出量随时间的延长趋于平缓,且Sn-0.75Cu焊料合金中Sn的浸出量最高,添加Ag元素后明显抑制了Sn-3·5Ag-0·75Cu焊料合金中Sn的浸出;Ag,Cu,Pb的浸出量随时间的延长呈线性增加,且Ag,Cu的浸出量较少。3种焊料合金浸出后表面产物层较厚,主要由Sn_4(OH)_6Cl_2和SnO组成,其中Sn-0.75Cu焊料合金的表面产物层有裂纹和孔洞,Sn-3.5Ag-0.75Cu焊料合金的表面产物相对致密,而Sn-37Pb焊料合金的表面产物局部出现剥落现象。这3种焊料合金浸出动力学行为存在差异,主要与表面产物的相组成和形貌有关。 相似文献
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碳纳米管铅锡复合减摩镀层的内应力研究 总被引:1,自引:0,他引:1
采用复合电沉积方法在紫铜片上制备碳纳米管铅锡合金复合减摩镀层;用阴极弯曲法研究了电流密度和镀液温度对碳纳米管铅锡复合镀层内应力的影响;在不同碳纳米管浓度的镀液中制备了复合镀层的试样,用X射线衍射法测定了各复合镀层的内应力.结果表明,碳纳米管铅锡合金复合镀层的内应力随电流密度的增加而升高,但随镀液温度的升高而降低.保证电流密度和镀液温度不变,碳纳米管的含量为2g/L,复合镀层的内应力降至最低;碳纳米管在镀层中的弥散分布起到了应力传递作用,减少了应力集中而产生的微裂纹. 相似文献
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本文采用Ni-Cr合金钎料,在Ar气保护条件下,对金刚石磨粒进行了激光钎焊试验研究。采用扫描电镜(SEM)和能谱仪(EDS)及X射线衍射仪(XRD)分析金刚石磨粒与Ni-Cr钎料结合界面的组织结构与物相组成,并研究了钎料与金刚石界面处碳化物的形成机理。测试结果表明,激光钎焊过程中在金刚石表面附近形成的富Cr层与金刚石表面的C元素反应生成碳化物Cr3C2,通过反应热力学与动力学分析显示界面反应产物可以依靠置换反应形成,使金刚石磨粒与钎料实现了牢固结合。 相似文献
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This paper presents the result of scientific examinations carried out on the soil-buried archaeological bronzes Ding from Yin Ruins of China. Eight of typical fragments from different bronze Ding were selected as researched samples according to their deterioration characteristics. Optical microscopy (OM), scanning electron microscopy coupled with energy (SEM-EDX), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to understand the corrosive morphological characteristics, to clear the nature of patina and to analyze the elementary composition of bronze Ding. The results indicated that it is not possible to distinguish the original lustrous metallic surface in most samples because of the corrosive crust. The substrate of bronze Ding contains74-86% Cu, 1.1-4.6% Pb, and 10-18% Sn, which is in agreement with the historical investigation in the ritual vessels of Shang time. Copper-containing compounds were the main constituents of natural patina: Cu2(OH)3Cl existed as corrosion product in all the powdery or crack surface; Cu2(OH)2CO3 was the main corrosive product in a compact and hard corrosive surface. This study provides useful information for the restoration and protection of bronze Ding in Yin Ruins. 相似文献
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LI Wen-sheng WANG Zhi-ping LU Yang YUAN Li-hua XIAO Rong-zhen ZHAO Xu-dong 《中国有色金属学会会刊》2009,19(2):311-318
Steady-state corrosion and wear behaviors of two Al-bronzes, Cu-14Al-X and QAl9-4, in 5.0% H2SO4 solution were investigated. It is found that wear loss of bronzes in 5.0% H2SO4 solution is lower than that in water or in air, namely, it exhibits negative synergy between corrosion and wear. Further analysis shows that corrosive solution plays an important role in cooling of specimen during the sliding wear to prevent the reduction of the surface hardness of specimen, induced by frictional heat. On the other hand, the bronzes suffer a de-alloying corrosion, and a noble copper subsurface and patina form on the specimen surface in corrosive solution, which has a passive function for further corrosion. The noble copper subsurface experiences strain hardening during the corrosion and wear, resulting in the increase of the surface hardness thus the increase in wear resistance. 相似文献
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M. A. Dudek R. S. Sidhu N. Chawla 《JOM Journal of the Minerals, Metals and Materials Society》2006,58(6):57-62
Severallead-free material systems are availableas replacements for traditional lead-based solders in microelectronic packaging,
including near-eutectic combinations oftin-rich alloys. Although these materials have superior mechanical properties as compared
to the Pb-Sn system, much work remains in developing these materials for electronic packaging. Small additions of rare-earth
elements have been shown to refine the microstructure of several lead-free solder systems, thus improving their mechanical
properties. This study investigated the effect of the addition of lanthanum on the melting behavior, microstructure, and shear
strength of an Sn-3.9Ag-0.7Cu alloy. The influence of LaSn3 intermetallics on microstructural refinement and damage evolution in these novel solders is discussed. 相似文献
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W. S. Li Z. P. Wang Y. Lu L. H. Yuan 《Journal of Materials Engineering and Performance》2006,15(1):102-110
The corrosion wear behaviors of two aluminum bronzes, Cu-14Al-X and QAl9-4, in 3.5% NaCl solution were investigated on a pin-on-block
reciprocating tester. It was found that the wear loss of the bronzes in 3.5% NaCl solution was lower than that in water and
in air, i.e., it exhibited “negative” synergy between corrosion and wear. To understand the corrosion wear mechanism of the
bronzes, the corrosion rate and polarization curves of Cu-14Al-X and QAl9-4 in 3.5% NaCl solution were determined. The worn
surfaces of the specimens were examined, and the wear tracks were measured using scanning electron microscopy. The corrosion
patinas formed on the specimen surfaces were studied with x-ray photoelectron spectroscopy and electron probe microanalysis.
The corrosive solution was shown to play an important role in cooling of the specimen surfaces during the wear, thus preventing
the specimen’s surface hardness from being reducing, induced by frictional heat during the sliding wear. On the other hand,
the bronzes suffered from dealloying corrosion; a noble copper subsurface and patina formed on the specimen surface in the
corrosive solution, which had a passive function for further corrosion. The noble copper subsurface experienced strain hardening
during the corrosion wear, resulting in an increase of the surface hardness and thus an increase in wear resistance. 相似文献
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LN2—3井油管腐蚀行为 总被引:1,自引:1,他引:0
采用一种实用的评价油管腐蚀状况的挂片装置,通过扫描电镜和X射线衍射仪对腐蚀产物分析,结合仿真模拟试验,研究了LN2-3井油管的腐蚀现状,结果表明,LN2-3井油管的腐蚀中度腐蚀. 相似文献
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对转炉煤气柜内腐蚀介质与腐蚀产物进行分析,探讨了柜内钢结构腐蚀的原因与机理。结果表明:柜内碳钢表面腐蚀产物主要由FeCO_3及少量铁氧化物和CaCO_3组成,煤气冷凝水中含有大量的HCO_3~-及Cl-等腐蚀性离子,因此气柜内钢结构腐蚀主要是由CO_2引起的,CO_2溶于冷凝水后,在碳钢表面形成一层弱酸性腐蚀液膜,使得钢结构表面发生了CO_2均匀腐蚀。由于柜内煤气温度较低,形成的腐蚀产物疏松,使得氧气、Cl~-等能渗透到碳钢表面,加速局部腐蚀,使得气柜侧壁及底板表面出现许多腐蚀孔洞。 相似文献