共查询到20条相似文献,搜索用时 187 毫秒
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《中国有色金属学报》2016,(1)
铝及铝合金以其优良的特性,在当代工业材料中占有越来越重要的地位。钎焊作为一种可靠连接铝及铝合金结构件的连接方法而被广泛应用。铝及铝合金钎焊用硬钎料的开发一直是国内外学者争相研究的热点,然而,钎料合金熔化温度高、加工成形性差、钎焊接头强度低等因素严重制约着钎料合金的开发应用,实现商业化的钎料甚少。添加合金元素能够降低钎料熔化温度,改善钎料显微组织和性能,这对铝钎焊用硬钎料的发展是一个行之有效的方法。结合国内外对铝及铝合金钎焊用硬钎料的最新研究成果,全面阐述合金元素的添加对钎料熔化温度、加工成形性及钎焊接头组织性能的影响,指明铝及其合金钎焊用硬钎料目前研究中存在的问题及今后的研究方向。 相似文献
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《中国有色金属学会会刊》2019,(4)
采用非晶和晶态Ti-25Zr-12.5Cu-12.5Ni-3.0Co-2.0Mo(质量分数,%)钎料对Ti-47Al-2Nb-2Cr-0.15B(摩尔分数,%)合金进行真空钎焊连接,对两种钎料的熔化行为、润湿铺展性、填缝隙能力以及由钎焊TiAl基合金所得的钎焊接头进行详细的研究。结果表明:与晶态钎料相比,非晶钎料具有更窄的熔化温度区间、更低的液相线温度和熔化激活能;同时,非晶钎料在Ti-47Al-2Nb-2Cr-0.15B合金表面上具有更优异的钎焊性。非晶和晶态两种钎料的钎焊接头均由两侧的界面反应层和中心钎焊层组成,非晶钎料钎焊接头的抗拉强度均高于相同钎焊工艺参数下的晶态钎料钎焊接头的抗拉强度,且在钎焊温度1273K下获得的钎焊接头的抗拉强度达到最大值254 MPa。 相似文献
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为了降低Cu-P钎料的熔化温度和改善其脆性,该研究在Cu-P钎料内复合一定质量分数的Ag,In和Sb,利用金相显微镜、扫描电镜、差热分析仪等研究了添加组元对钎料显微组织、熔化温度、铺展性、力学性能和钎焊性能的影响.结果表明,各添加组元在钎料内分布均匀,实现了预期的目标;添加3种组元后钎料的熔化温度为697 ~711℃,与传统的Cu-P钎料相比已大为降低;相同的钎焊温度下,添加Ag,In和Sb的Cu-P钎料的铺展面积明显大于Cu-P钎料;拉伸试验表明,五元系钎料的抗拉强度达到了718.1 MPa.此外,采用该钎料钎焊黄铜与紫铜得到的接头内母材/钎料界面处形成了致密的连接,无缺陷存在;钎缝组织内各相分布均匀,无气孔夹渣存在,满足使用要求. 相似文献
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研究了Sn元素对Ag-Cu-In合金钎料加工及钎焊性能的影响。结果表明:Ag-Cu-In合金钎料中加入一定量的可以有效降低钎料的熔化温度,当8%Sn元素加入Ag-Cu-In合金中,其熔化温度降低为575~620℃,可以加工为0.10 mm厚的带材,钎焊性能良好;随着合金中Sn元素含量的增加,合金钎料中的脆性相增多、变大,导致合金的加工性能变差,不能成型。 相似文献
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以BAg50CuZn钎料为研究对象,在其表面电镀锡,借助扫描电镜(SEM)观察锡镀层的表面形貌,采用差热分析仪(differential scanning calorimetry,DSC)和润湿试验炉分析锡镀层对合金钎料熔化温度和润湿性能的影响,并对镀覆锡后合金钎料的成分进行了讨论.结果表明,随着钎料表面镀覆Sn元素含量增加,合金钎料的DSC吸热峰向左偏移、熔化温度降低,钎料的润湿铺展性能呈上升趋势.在镀覆Sn元素含量为4.8%(质量分数)时,合金钎料表面锡镀层平整、致密,钎料的铺展面积最大,为236 mm2.镀覆元素Sn后的钎料中,Ag,Cu,Zn元素含量均减少,元素含量降低幅度大小顺序依次为Cu,Ag,Zn. 相似文献
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《Science & Technology of Welding & Joining》2013,18(6):502-508
AbstractThis study was carried out to develop cadmium free silver based brazing filler metals that meet the following requirements. First, they have to have a melting point lower than that of BAg-1 brazing filler metal. Second, they have to have not only good wetting characteristics and the ability to produce a sound joint with excellent mechanical properties but also plastic formability. Using the calculated phase diagrams on Ag–Cu–Zn–Sn quaternary system alloys, the authors selected several alloys with a possibility of meeting the above requirements. The melting point and other properties, such as hardness and brazeability of the selected alloys, were evaluated. As a result, the authors successfully developed silver based brazing filler metals that have a low melting point below ~600°C and meet the above requirements by adding a small amount of indium as an alloying element into the Ag–Cu–Zn–Sn quaternary system alloy. The newly developed brazing filler metals are slightly inferior in wetting characteristics to BAg-1; however, the brazing filler metal containing ~3 mass-% indium element showed wetting characteristics comparable to those of BAg-1. Furthermore, the new brazing filler metals could produce joints with a high tensile strength equivalent to ~83% of that of a joint brazed using BAg-1. 相似文献
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金首饰用无镉K金钎料的研究与发展 总被引:1,自引:0,他引:1
概述了金属镉在金首饰合金钎料中的作用和无镉K金钎料的合金化原理,给出了近年开发的9K~22K颜色和白色无镉K金合金钎料的成分和熔化温度范围,指出:在K金首饰应用领域,开发适合分级钎焊的高性能无镉K金钎料系列以及无镉K金钎料的标准化和商业化,依然是无镉K金钎料的发展方向。 相似文献
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《Science & Technology of Welding & Joining》2013,18(5):423-429
AbstractA suitable selection of the filler metal is vital for producing satisfactory brazed joints. The wettability of brazing alloys with base metals depends on physical properties such as surface tension, density, melting point, and viscosity. Thermal conductivity and electrical resistivity are also important since the filler metal is frequently required to have similar values to those of the base metal. In the present paper, the physical properties of liquid alloys relevant to brazing have been evaluated. Six different filler metal systems were analysed, comprising alloys based on Ag, Al, Au, Cu, Ni, and Ti. Results show that the viscosity values for most binary brazing filler alloys are of the order of 2–8 mPa s, with Cu and Al alloys exhibiting the lowest viscosities. The surface tensions of brazing alloys vary from 800 to 1800 mN m-1, with the lowest surface tension values corresponding to the Ag and Al alloys. Thermal conductivity and electrical resistivity values fall in the range 10–200 W m-1 K-1 and 17–300 μΩ cm, respectively. 相似文献
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以BAg50CuZn钎料为基材,采用电镀热扩散组合工艺制备了镀锡AgCuZnSn钎料。为了揭示镀锡银钎料的热力学特性,借助差示扫描量热仪(DSC)测定了镀锡银钎料的熔化温度,运用热分析动力学中的非等温微分法和积分法分析了镀锡银钎料的相变热力学特性,并利用金相显微镜和X射线衍射仪(XRD)对钎料熔化后润湿界面的显微组织和物相进行了分析。研究表明,随着Sn含量升高,在吸热峰镀锡银钎料由固态向液态转变的温度区间变窄,非等温微分法和积分法得到的钎料相变活化能均逐渐增大。在Sn含量为7.2%时,镀锡银钎料的相变活化能和指前因子最大,分别为555.56kJ/mol、1.41×10~(32),此时镀锡银钎料相变速率方程的表达式为:k=1.41×10~(32)exp(-5.56×10~5/RT)。7.2%Sn含量的镀锡银钎料在304不锈钢表面熔化后,润湿界面组织主要由Ag相、Cu相、CuZn相、Cu_5Zn_8相、Cu_(41)Sn_(11)相、Ag_3Sn相组成。 相似文献
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本文提出一种不含Si的镍基Ni-Cr-Co-B高温钎料.对一系列Ni-Cr-Co-B钎料的熔化特性、钎焊工艺性能、钎料组织以及钎焊接头的室温和高温强度、接头韧性进行了研究,并与标准镍基钎料BNi-1a和BNi-5进行了比较研究结果表明,Ni-Cr-Co-B钎料钎焊的高温合金接头的高温性能和韧性均超过标准镍基钎料. 相似文献
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用感应熔炼方法制备了一系列InAg钎料,考察银添加量对铟基钎料性能的影响。采用化学分析和X射线衍射(XRD)对钎料的成分和物相进行了对比分析;采用示差扫描量热仪(DSC)测试了不同成分钎料的熔点;利用扫描电镜(SEM)对In-7Ag焊料与基体的界面反应进行了研究,并测试了不同成分钎料的润湿性及接头剪切强度。结果表明,In-7Ag具有较大的剪切强度以及良好的润湿性,是月球样品返回装置密封材料的不错选择。焊料与密封材料剧烈反应可能弱化焊接组织的一致性,不利于金属密封,因此,寻求合适的焊接温度和时间是未来研究的重点。 相似文献
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Three groups of brazing alloys were compared in brazing chemical-vapor-deposited (CVD) diamond, including two nickel-based
alloys (Ni-3Fe-7Cr-3B-0.5Si-0.02C and Ni-14Cr-10P-0.02C), one copper-based alloy (Cu-10Sn-15Ti), and two silver-based alloys
(Ag-5Cu-1Al-1.25Ti and Ag-34.25Cu-1In-1.75Ti). The nickel-based alloys catalytically transformed the sp3-bonded diamond into sp2-bonded carbon during high-temperature brazing operation though with the existence of Cr as the active metal. The bonding
strength was very low and the fracture primarily propagated through the sp2-bonded carbon. For Cu-10Sn-15Ti brazing alloy, the transformation of the sp3-bonded diamond into sp2-bonded carbon during high-temperature brazing operation was marginal. The bond strength was adequate and fracture took place
primarily through the brazing alloy bulk, due to the high concentrations of Sn and Ti that caused the precipitation of abundant
intermetallic compounds in the brazing alloy bulk. For Ag-based alloys having very low concentrations of Ti, no visible degradation
of diamond was observed and the bonding strength was very high. Crack primarily propagated through the brazed interface or
even the CVD diamond bulk. 相似文献
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The melting point, microstructure, phase, and electrochemical behavior of Ti-21Ni-15Cu alloy, together with two-, three-,
and four-component low-melting-point titanium-base brazing alloys, are presented in this paper. Five filler metals were selected
for the study, in which melting points were measured by differential thermal analysis, phases identified by x-ray diffractometry,
and corrosion behaviors tested by potentiodynamic polarization. The experimental results show that the three-component Ti-15Cu-15Ni
and the newly developed Ti-21Ni-14Cu alloys exhibit the combination of lower melting point and superior corrosion resistance
compared to the two-and four-component titanium alloys, 316L stainless steel, and a Co-Cr-Mo alloy in Hank’s solution at 37
°C. On a short time basis, the presence of Ti2Ni and Ti2Cu intermetallics in the Ti-15Cu-15Ni and Ti-21Ni-14Cu alloys should not be preferentially dissolved in galvanic corrosion
with respect to the dissimilar Ti-6Al-4V alloy. 相似文献