田艳红杨世华王春青王学林林鹏荣
金属学报
doi:DOI:10.3724/SP.J.1037.2009.00688
采用直径范围为200-600 μm的Sn3.0Ag0.5Cu无铅钎料球在Cu焊盘上制作热风重熔焊点, 将重熔焊点在150 ℃下进行老化, 并对重熔和老化焊点进行剪切测试. 结果表明: 重熔和老化后焊点的剪切强度都随体积的增大而减小, 表现出显著的体积效应. SEM断面观察显示: 较小体积焊点剪切断裂发生在钎料块体内部, 表现出较好韧性; 较大体积焊点则发生在近焊盘的界面处, 呈现脆性断裂特征. 焊盘界面处和钎料内部微观组织SEM观察表明: 小体积焊点内部Ag3Sn化合物以小颗粒状弥散分布, 起到强化作用; 而大体积焊点内部Ag3Sn化合物为树枝网状分布, 表现出硬脆性. 金属间化合物(如Ag3Sn和Cu6Sn5)的形貌和分布对焊点的断裂行为有显著的影响, 是焊点剪切断裂行为体积效应的内在原因.
关键词:
无铅焊点
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shear fracture
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volume effect
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intermetallic compound
殷为民
,
郭建亭
,
胡壮麒
金属学报
研究了Mg在Fe_3Al合金中的分布及其对力学性能的影响适量的Mg(0.002wt-％)明显改善Fe_3Al的室温和高温力学性能Auger分析表明,Mg偏聚在晶界TEM观察发现,适量Mg增加晶界协调晶内变形的能力,使位错易于穿过晶界继续滑移变形SEM观察表明,Fe_3Al合金室温下均呈穿晶解理特征,裂纹源在晶界上
关键词:
Fe_3Al,Mg
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intermetallic compound
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microalloying
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mechanical property
沈华清
,
曾潮流
,
吴维
,
郭建亭
金属学报
用涂盐法并借助扫描电镜、光谱分析,金相,电子探针及X射线衍射等技术研究了Ni_3Al金属间化合物在O_2/SO_2/SO_3气氛中600-800℃温度范围内(Na,K)_2SO_4引起的低温热腐蚀行为结果表明,Ni_3/Al发生了低温热腐蚀,其腐蚀速度在750℃呈现一最大值热腐蚀的发生主要归因于多元共晶盐的形成盐沉积加速了材料在空气中的氧化CoCrAlY涂层能改善合金的耐蚀性能
关键词:
热腐蚀
,
Ni_3Al
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intermetallic compound
,
sulphate
林栋梁
,
陈达
金属学报
通过SEM动态拉伸形变试验,研究了具有各种化学成分和不同热处理态Ni_3Al合金的形变滑移特征,并用TEM观察了晶界区域的位错组态。研究结果表明,在含硼Ni_3Al合金的晶界附近存在一个过渡滑移区,该区域中滑移线重新取向或其它滑移系开动,从而产生了局部应变调节并使晶界应力集中松弛。硼降低了开动晶界位错源所需的应力并可能同时增加了位错源本身的数目。硼对Ni_3Al的韧化作用强烈受到基体Al含量、合金元素及热处理等因素的影响。
关键词:
Ni_3Al
,
intermetallic compound
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deformation
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slip
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dislocation
褚武扬
,
肖纪美
,
A.W.THOMPSON
金属学报
对解理开裂,对氢致解理,氢能促进位错的增殖和运动,从而σ_0(H)<σ_0,k>1,即σ_F(H)<σ_F,K_(IH)
关键词:
Ti_3Al
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intermetallic compound
,
hydrogen induced crack
王理明
,
祝东
,
姚枚
,
蔡其巩
,
邹敦叙
金属学报
采用系列温度及不同应变速率条件下的压缩试验研究TiAl,TiAl-V的塑性形变行为结果表明,在不同温度区间,Peierls—Nabarro机制,交滑移机制和蠕变为塑性形变的主要控制机制,TiAl-V合金在600—700K形变时出现反常应变速率效应,而且塑性应变量越大.反常效应越明显,利用位错交滑移的热激活特性理论对此反常效应进行初步解释,温度和应变速率对加工硬化指数的影响及不同塑性应变量对应变速率敏感性的影响在本文中也进行了探讨。
关键词:
TiAl金属间化合物
,
intermetallic compound
,
strain rate
SUN Chao GUO Jianting TAN Minghui LI Hui WANG Shuhe Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The effects of Cr and Nb on tensile properties at room and elevated temperatures and also on the microstructure have been investigated.An improvement in ductiliy plasicity and the cleavage strength of Fe_3AI may result from adding Cr;the improvement is more pronounced at over 400℃.The formation of Fe_2Nb containing A1 precipitates in the Fe_3AI+Nb alloy provide significant strengthening effect.Additions of Cr and Nb in Fe_3AI can cause a signifi- cant improvement in the yield strength at 550℃.
关键词:
intermetallic compound
,
null
,
null
,
null
,
null
GUO Jianting SUN Chao TAN Minghui LI Hui LAI Wanhui Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The effect of alloying element such as Mo,Si or B and its stoichoimetric composition on the tensile properties at room and elevated temperatures,and also on the microstructure of Fe_3Al and FeAl alloys has been investigated.Two Fe aluminides were found to be obviously strengthened by all of three elements,but seriously embrittled by Mo and Si.An improvemen over the plasicity of FeAl may be made by adding B,and the fracture surface is variedfrom intergranular to transgranular cleavage type.The room temperature plasticity of the Fe-rich Fe_3Al or Al-rich FeAl is much better than that of the stoichoimetric aluminides.An anoma- lous temperature dependence on the yield strength of Fe_3Al in range of 400 to 500℃ or of FeAl in range of 400 to 500℃ was found.Discussion has been carried out by the aspect of microstructure.
关键词:
intermetallic compound
,
null
,
null
,
null
,
null
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null
