焊接间隙对不锈钢钎焊缝性能的影响

文中采用BNi-2钎料（BNi82CrSiB）对1Cr18Ni9Ti不锈钢进行了真空钎焊,钎焊后对样件进行了拉力试验,并使用扫描电镜对接头组织进行了分析,以研究焊接间隙对钎焊缝性能的影响。研究结果表明,接头组织基本由固溶体、金属间化合物及母材近焊缝区域附近的网状组织组成。随着钎缝间隙的增大,钎缝的组织会出现大量的金属间化合物,钎焊接头的综合性能会随之下降,钎缝的强度也随着钎缝间隙的增大呈现明显的下降趋势。     

AOD转炉氧枪喷头国产化研制

国产化的φ168 mm氧枪喷头在试用过程中,完全达到了进口氧枪喷头的使用寿命.通过在实际冶炼过程中的性能比较,国产化氧枪喷头完全可以替代进口.     

钎料成分对陶瓷/钎缝界面结合及组织的影响

采用不同配比的Ag-CuO钎料在空气中对陶瓷进行钎焊试验，通过扫描电镜，能谱分析，X射线衍射等方法对钎焊接头的显微组织、结构、元素分布进行分析。结果表明在钎料中添加适量CuO显著提高了钎料对陶瓷母材的钎焊性能，克服空气中钎焊容易氧化的缺点；ZrO2陶瓷与钎缝界面区产生CuO相和Ag相组成的黑色过渡层；当钎料中CuO的摩尔分数为34％时，界面区的组织和成分最均匀，元素之间的相互扩散和溶解情况最好，Cu，Ag元素向陶瓷中扩散的距离约50μm。     

铝钎焊用锌基合金钎料的制备及钎焊接头的组织和抗剪强度

采用高频感应加热装置制备了锌基合金钎料,并以纯铝为母材进行润湿试验,并采用该钎料分别对2A12铝合金、55%SiCp/Al复合材料进行钎焊,分析了合金钎料的显微组织、成分、熔化温度范围,并对合金钎料及钎焊接头的拉剪强度进行了测试。结果表明:自制锌基合金钎料主要由α-Al固溶体、η-Zn固溶体和共晶组织组成,熔化温度区间为361~398℃;锌基合金钎料在纯铝上具有较好的润湿性;使用锌基合金钎料钎焊铝合金,其钎缝组织为η-Zn相、细小的共晶组织、树枝状及块状的α-Al相;钎焊55%SiCp/Al复合材料,其钎缝组织由铝的共析组织、η-Zn相、条纹状共晶组织及细小的共晶组织组成;钎料、2A12铝合金钎焊接头以及55%SiCp/Al复合材料钎焊接头的抗剪强度分别为237,127,109 MPa。     

硬质合金新型钎焊工艺研究

本文通过针缝组织、元素扩散及接头性能的试验分析，提出了使用银墓钎料时硬质合金的新型针焊工艺，即预先加压钎焊，随后高温高压扩散处理的工艺，在较低的焊接温度下获得了大大高于一般钎焊工艺所得到的接头性能。     

ZK60镁合金的炉中钎焊工艺

采用高纯锌箔钎料对ZK60镁合金在不同条件下进行炉中真空钎焊,并用扫描电镜、硬度仪和X射线衍射仪研究了钎焊接头的显微组织、显微硬度及钎缝的物相组成。结果表明:钎焊温度和保温时间对接头的组织和性能影响较大;当钎焊温度445℃、保温时间45s时,接头质量较好,钎缝无气孔、裂纹,显微硬度较高;钎缝组织细小、均匀,其物相组成为α-Mg及γ-MgZn。     

钎缝间隙对316L不锈钢真空钎焊接头组织和硬度的影响

采用BNi-2+40%BNi-5镍基混合钎料对316L不锈钢进行三种纤缝间隙的真空钎焊,通过光学显微镜、扫描电镜、X射线能谱仪及硬度计等研究了三种钎焊接头的显微组织、钎缝元素分布以及钎缝显微硬度。结果表明:316L不锈钢的钎焊接头主要由固溶体、连续共晶和金属间化合物及网状组织组成;随着钎缝间隙的减小,钎焊接头中金属间化合物的含量逐渐减小,接头元素、硬度分布更加均匀;当钎缝间隙为30μm时,接头组织基本为固溶体,综合性能最好。     

Cr12钢与YG8硬质合金焊接接头组织及性能研究

硬质合金主要用于制造刀具、采掘工具以及整体刀具等双金属结构,切削部分为硬质合金,基体为钢。大部分硬质合金工具是用焊接的办法镶嵌在基体上使用,焊接工艺参数将直接影响焊接接头的组织性能。采用真空钎焊焊接Cr12钢与YG8硬质合金,研究不同钎缝宽度对焊接接头组织及性能的影响。通过试验表明,采用Cu MnCo钎料,在1 070℃温度下真空钎焊,钎缝宽度控制在0.1 mm,所得到的焊接接头抗弯强度最高,组织性能最好。     

铜粉添加量对不锈钢钎焊接头组织和显微硬度的影响

在BNi-7镍基钎料中添加纯铜粉制成组合钎料,然后采用真空方法在板间隙为40μm的条件下钎焊316L不锈钢,研究了铜粉含量对钎焊接头组织和显微硬度的影响。结果表明:在BNi-7钎料中添加纯铜粉能有效改善较大间隙接头的填充性能;添加纯铜粉后,钎缝中的脆性化合物显著减少,并呈岛状、条状、麻点状等镶嵌在镍基固溶体中,导致接头的显微硬度降低,当添加纯铜粉的质量分数为9%时,钎缝中的脆性化合物最少,接头的显微硬度为1 000 MPa。     

5A06铝合金/T2紫铜镶嵌结构件超声波复合钎焊

研究了Zn-5Al-3Cu钎料超声辅助钎焊5A06铝合金和工业纯铜镶嵌结构的工艺。利用金相、SEM等方法研究了钎缝微观组织特征,探究了超声对钎缝形成过程的影响,讨论了接头的力学性能与微观组织的关系。试验结果表明,镶嵌结构各区域钎缝的组织致密无缺陷。钎缝由树枝晶状α-Al、Zn-Al-Cu-Mg四元共晶组织、η-Zn相和Cu-Al_2化合物构成,5A06铝通过Zn-Al过渡层与钎料组织结合,铜侧界面反应层厚度均匀,约2～3μm,主要由CuZn5化合物构成,部分CuZn5和钎料的界面间可观察到CuAl_2和Al_(4.2)Cu_(3.2)Zn_(0.7)化合物。接头的剪切强度为89～100 MPa,主要断裂于CuZn_5化合物和铜基体的界面处。     

Preparation mechanism and grinding performance of single-layer self-lubrication brazed CBN abrasive wheels

In order to fabricate single-layer self-lubrication brazed cubic boron nitride (CBN) abrasive wheels, brazing experiments of graphite particles and AISI 1045 steel were carried out using Ag–Cu–Ti filler alloy. Optical microscope, scanning electron microscope, energy-dispersive spectroscopy, and X-ray diffraction were employed to characterize the microstructure and phase constitution of the brazing interface between graphite particles and Ag–Cu–Ti alloy. The formation mechanism was discussed. The results show that TiC resultants are formed via the diffusion behavior of Ti atoms and C atoms towards the joining interface. The chemical resultants of TiC have the granular shape at the early stage. Then, they grow across the joining interface between the graphite particle and Ag–Cu–Ti alloy. Finally, the continuous lamellar TiC compounds come into being around the graphite particle. Chemical joining of graphite particles and Ag–Cu–Ti filler alloy is accordingly realized. A comparative experiment displayed that the single-layer self-lubrication brazed CBN abrasive wheel has better performance than the conventional brazed counterpart.     

Microstructure and phase constitution near the interface of Cu/3003 torch brazing using Al-Si-La-Sr filler

It has been mainly studied in this paper on brazing of Cu to Al using Al-Si filler metal. The optimized scanning rate of 2.5 mm/s is first obtained through simulating the temperature field of Cu-Al brazing process based on ANSYS software. Then the brazing of Cu-C11000 to Al-3003 using Al-Si-La-Sr filler is carried out by torch brazing technology. It is found that the brazing seam region is mainly consisted of α-Al solid solution and CuAl₂ IMC. Further experimental results also show that the rare earth element La in filler metal can not only refine the grain, but also promote the dispersion of intermetallic compounds into the brazing seam, which significantly improves the brazing seam microstructure and mechanical properties of the joints.     

ZrO2陶瓷与钛合金非晶钎焊

由于陶瓷的线膨胀系数与金属的线膨胀系数相差很大,因此在通过焊接连接陶瓷与金属时,热作用势必会在接头区域会产生幅值较大的残余应力,进而降低接头的力学性能,严重时甚至会导致连接陶瓷接头的断裂。这使得陶瓷与金属的连接是一个广受关注但又未能得到很好解决的科学问题。采用非晶钎料实现ZrO2陶瓷与Ti-6Al-4V合金的钎焊连接,研究焊接工艺参数对接头的组织与性能的影响。结果表明接头界面组织结构为ZrO2陶瓷/Cu2Ti4O+(Ti,Zr)2Cu/TiO+Ti2O/CuTi2+(Ti,Zr)2Cu/ CuTi2/Ti-6Al-4V合金。钎焊温度、保温时间和冷却速度对界面组织结构有最大的影响,主要体现在反应层的厚度和脆性(Ti,Zr)2Cu相的变化。接头的剪切强度随钎焊温度、加热时间和冷却速度的增加而降低。最佳工艺参数为焊温度1 173 K,保温时间10 min,冷却速度5 K/min,其钎焊接头剪切强度可以达到165 MPa。     

TC4合金空心可调叶片的钎焊工艺研究

某机压气机的空心可调节叶片组件是由钛合金材料TC4合金通过钎焊制成的,每个叶片都是由叶片主体和2个叶形板组成,叶片主体与叶形板之间采用钎焊连接。本文针对空心叶片组件的结构特点和使用要求开展了真空钎焊工艺研究,进行了钎料钎焊接头力学性能测试,同时,就钎焊热循环对TC4合金性能的影响、钎焊工艺路线程序、叶片焊后变形校正等工艺问题进行了深入研究,所确定的真空钎焊工艺程序可以钎焊出合格的可调叶片组件,钎焊质量稳定。     

Portholes-equal channel angular pressing: novel technique for extrusion of 6061 aluminum alloy tube by subsize billet

Wrought 6061 Al alloy exhibits the prospective applications in the form of tube extrusions. In this study, billets of 6061 Al alloy were extruded under optimized conditions by a novel technique namely portholes-equal channel angular pressing (P-ECAP) extrusion. This technique is different from the conventional extrusion as the dimension of the product is greater than that of the billet. The extruded tube produced by the method was characterized for their microstructure as well as for their physical and mechanical properties. The tube that was fabricated using P-ECAP die showed significant refinement in microstructure with improved mechanical properties outside the seam joint portion. However, the extrusion loads using porthole die were less compared to that in the conventional method by using columniform billet because of the decrease in billet dimension or extrusion ratio. Furthermore, microstructure at seam joints of 6061 Al alloy extrusion was discussed in detail in this study. Thus, the P-ECAP technique has significant potential for substantial energy saving.     

电触头钎缝组织形态对接头力学性能的影响

提出了触头的钎焊强度不仅与钎着率有关,而且还受钎缝组织形态影响.当钎着率在75%以上时,触头钎焊强度随钎缝中共晶体组织含量的增加而降低.     

中间层厚度对H62 黄铜精密构件瞬时液相连接的影响

瞬时液相( Transient Liquid Phase,TLP) 连接是利用中间层材料与母材的冶金反应产生液相实现的,它可以弥补常规毛细钎焊的某些缺陷。文中采用Ag 作为中间层进行了H62 的瞬时液相连接,得到了性能优良的接头。试验结果表明:中间层厚度对瞬时液相连接质量影响很大。当Ag 中间层厚度为6 滋m 时,液相量合适,形成的少量液相在压力作用下填满钎缝,获得了良好的接头瞬时液相连接组织,同时实现了圆角尺寸的控制,减小了接头变形。     

Study on diamond vacuum brazed with Cu-based filler metal containing Cr

To reduce the thermal damage to the diamond and production cost, Cu-Sn-Ni-Cr and Cu-Sn-Cr were used to braze the diamond. SEM, EDS, and XRD were used to analyze the morphology of the diamond and the microstructure of the interface and the brazing alloy. Graphitization of the brazed diamond was tested by laser Raman, and the static compressive strength and toughness index of the diamond abrasive were measured. The results show that it realizes chemical metallurgical bonding between the diamond and either of these two filler metals, while Cu-Sn-Ni-Cr shows better wettability to the diamond. The brazed diamond has complete morphology and smoothing surface, there is almost no graphite in the diamond, but the static compressive strength and TI decrease slightly. On the surface of the diamond, it generates continuous laminar (Cr, Fe)₇C₃. The bonding strength between the diamond and the filler metal can meet the need of grinding. During the solidification process of the brazing alloy, dendrite α-Cu precipitates out firstly; then there is peritectic transformation and eutectoid transformation to form dendrite α-Cu, Cu_6.5Sn, Cu₉NiSn₃, and eutectoid α-Cu.     

钎焊金刚石薄壁小孔钻研制

以Ni-Cr合金为钎料,分别用真空加热和高频感应加热两种方式进行了金刚石磨粒与0Cr18Ni9不锈钢基体的钎焊,制作了基体外径为3 mm的薄壁小孔钻头。进行了半钢化玻璃钻削试验,用扫描电子显微镜观察钻削试验前后钻头的微观形貌。结果表明:两种钎焊工艺皆实现了金刚石磨粒的高强度连接;加热源不同及金刚石磨料出露高度差异性是影响钻头磨损方式的主要因素;为确保钻头的寿命和高效,磨粒出露高度应控制在其自身高度的50%-60%之间。     

TiAl/40Cr感应钎焊接头界面结构及力学性能分析

以Ag-Cu-Ti为钎料对TiAl与40Cr进行了感应钎焊试验。采用扫描电镜、电子探针和X射线能谱分析仪等分析测试手段对界面组织及生成相进行了分析;测试了接头的抗拉强度及界面生成相的显微硬度。结果表明,钎缝处出现了Ti Al3、Ag[s,s]、Ti(Cu,Al)2三种反应相,当钎焊温度为1 143~1 183 K时, 接头的界面结构为TiAl/ TiAl3 /TiAl3 + Ag[s,s]/ Ti(Cu,Al)2 + Ag[s,s] / Ag[s,s] + Ag-Cu共晶相/ 40Cr;当钎焊温度为1 223 K时,接头的界面结构为TiAl / Ti(Cu,Al)2+少量Ag[s,s]/ Ag[s,s] + Ag-Cu共晶相/ 40Cr。在试验所选的工艺参数范围内,最佳规范为连接温度为1 143 K,保温时间为5 min,此时接头的抗拉强度达到267 Mpa。