Development of high precision joints in particle accelerator components performed by vacuum brazing

Sánchez, Laura; Carrillo, D.; Rodríguez, Enrique Páez; Aragón, F.; Sotelo, Jose; Toral, Fernando

doi:10.1016/j.jmatprotec.2011.03.009

Cited by 22 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It resulted in substantial intergranular in ltration, which signi cantly reduced the toughness of the joints. Sanchez et al [23] studied the effect of stainless steel surface nickel plating thickness on vacuum-brazed joints between stainless steel and bronze. The study showed that the brazed joints with 20-30 µm thick nickel plating had a multilayer microstructure and high Ni element content due to the thick nickel layer.…”

Section: Introductionmentioning

confidence: 99%

Effects of nickel layer on interfacial micro-structure distribution and macro-mechanical properties for vacuum-brazed dissimilar steel joints

Wang

Wei

et al. 2023

Weld World

View full text Add to dashboard Cite

In this paper, nickel-plated Q235 carbon steel and 304 stainless steel were vacuum brazed together using pure copper foil as the ller metal. The effects of nickel plating at the carbon steel surface on the shear strength of the brazed joints were investigated and veri ed by the nite element analysis method. The microstructure and shear strength of the brazed dissimilar steel joints were characterized by SEM and tensile experiments. The results found that the pure copper brazing material exhibited excellent wettability to the base metal. With the increase of heat treatment temperature and holding time, the plated Ni particles fuse with each other and the boundary of the Ni particles gradually disappears, which increases the diffusion distance of Fe, Ni, and P elements and the width of the interface transition zone.The maximum shear strength of the brazed dissimilar steel joint without the nickel layer is 265.9 MPa for the optimized brazing parameters with 0.06 mm thickness of pure copper foil. After nickel plating on the carbon steel surface with heat treatment of 500 ℃ for 1 h, the shear strength of the brazed dissimilar steel joint reduces to 213.4 MPa, which may be due to the formation of brittle intermetallic compounds by Ni and P elements on the surface of the layer at high temperatures.

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of nickel layer on interfacial micro-structure distribution and macro-mechanical properties for vacuum-brazed dissimilar steel joints

Wang

Wei

et al. 2023

Weld World

View full text Add to dashboard Cite

show abstract

“…Unfortunately, the joining of copper to stainless steel is challenging because of the differences in melting point, thermal expansion coefficient, wettability and thermal conductivity between stainless steel and copper [4,5]. Many studies on the connection of copper and stainless steel have been carried out to obtain defect-free joints by laser welding, tungsten/metal gas-suspended arc welding, diffusion bonding and vacuum brazing [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Li Xiangbin et al performed vacuum brazing on 100 mm SS and CuCrZr pipe with foil-shaped BAg-6 filler at 690 • C and a pressure of 8 × 10 −3 Pa, and the shear strength of the as-brazed joint was higher than 90 MPa [15].…”

Section: Introductionmentioning

confidence: 99%

Vacuum Brazing and Performance Evaluation of T2 Copper Block and 316L Stainless Steel Tube

Wang

Shang

Zeng

et al. 2023

Metals

View full text Add to dashboard Cite

The International Thermonuclear Experiment Reactor (ITER) Thermal shield (TS) serves as a cryogenic heat exchanger to maintain the thermal stability of the ITER superconducting magnet coil, which is critical to the control of the plasma during the operation of the ITER device. The TS is composed of long-length 316L stainless steel (SS) and copper as brazed joints. In this case, a feasible fabrication design for the CCS TS is presented, accomplished by three kinds of joining processes (vacuum brazing, friction stir weld, and TIG weld). In the reliable fabrication design, the brazing quality of the as-brazed long-distance 316L SS and copper joints plays a critical role in the thermal conductivity performance of the ITER thermal shield. Therefore, a high-quality vacuum brazing process of long-length SS/Cu joints applied in a low-temperature superconductor magnet system was first studied. The macro metallography analysis demonstrates the braze ratio of the samples is 100%, and no crack or defect is observed in the samples. The microstructural characterization reveals the brazing seams are composed of silver-based Ag-rich eutectic. The micro-shear test indicates that the shear strength of the 316L tube and copper joint is 205 MPa, with the fracture position located on the copper side; this zone will be the most vulnerable zone of the joints. In addition, the SEM results illustrated that the shear fracture morphology displayed a ductile fracture feature. The test results demonstrated that the highly precise depth drilling employed in this paper ensured a good control of the brazing clearance, resulting in a 100% braze ratio for the long-length SS/Cu joints. Therefore, it can be concluded that the brazing process can be applied in the ITER TS for the good thermal conductivity performance of long-length SS/Cu-brazing joints.

show abstract

“…Joining of ceramics is often an essential part of the fabrication process for ceramic components. Vacuum brazing is the universally accepted joining process for ceramics [11,12]. The requirement of obtaining acceptable ceramic brazed joints is met through either by metallizing mating ceramic surfaces [13][14][15][16] or by using active brazes filler.…”

Section: Introductionmentioning

confidence: 99%

An Experimental Study on Electroless Nickel Plating on Alumina Ceramic

Gupta¹,

Nihore²,

Sankar³

et al. 2021

cme

View full text Add to dashboard Cite

In this paper a low temperature metallization i.e. standardization of electroless Ni plating on alumina ceramic is summarized. It includes three main steps (i) pre-treatment, (ii) activation and (iii) Ni plating. Pre-treatment includes degreasing with non-silicate soap solution followed by ultrasonic cleaning in acetone and etching the alumina surface to generate roughness for making it suitable for adhesion. Etching has been obtained by immersion in 10% NaOH at 50°C for 10 minutes and 50% HF for 15 minutes at room temperature. Activation of the surface is the most important step before electroless plating on alumina ceramic. Activation has been achieved with Ginplate 442 (commercial chemical) by immersing the alumina specimen for 5 minutes at room temperature. Activated alumina samples have been used for electroless Ni plating in Ginplate 418 bath at 88°C.Uniform, densely compact coating has been achieved as revealed by SEM image. XRD plot confirms the presence of metallic nickel together with phases of Ni 2 P, NiP, Ni 3 P confirming the nickel phosphite based plating. Subsequently, tube to tube joining of these metallized alumina ceramic tubes has been conducted through vacuum brazing process with copper silver eutectic alloy (28Cu-72Ag) whose cross section showed good joint with excellent wettability of Cu-Ag with Ni plating.

show abstract

Development of high precision joints in particle accelerator components performed by vacuum brazing

Cited by 22 publications

References 6 publications

Effects of nickel layer on interfacial micro-structure distribution and macro-mechanical properties for vacuum-brazed dissimilar steel joints

Effects of nickel layer on interfacial micro-structure distribution and macro-mechanical properties for vacuum-brazed dissimilar steel joints

Vacuum Brazing and Performance Evaluation of T2 Copper Block and 316L Stainless Steel Tube

An Experimental Study on Electroless Nickel Plating on Alumina Ceramic

Contact Info

Product

Resources

About