scholarly journals Micro-Brazing of Stainless Steel Using Ni-P Alloy Plating

2019 ◽  
Vol 9 (6) ◽  
pp. 1094
Author(s):  
Shubin Liu ◽  
Ikuo Shohji ◽  
Makoto Iioka ◽  
Anna Hashimoto ◽  
Junichiro Hirohashi ◽  
...  

A Ni-P plated layer of 20 μm thickness containing 11 wt.% P was formed on the surface of a stainless steel (SUS304) plate by electroplating. The microstructure and joint strength of the brazed joint with the electroplated Ni-11P layer were investigated. The results indicated that the filler metal was homogeneously distributed between the SUS304 plates and no voids or flaws formed in the brazed filler zone. Fe-Ni-Cr solid solutions were formed at the brazed interface. Moreover, P was mainly concentrated in such brazed filler zone to form P-containing phases. The average shear strength of the brazed joints was determined to be 47.3 MPa. The results demonstrated that the brazing of SUS304 plates using the electroplated Ni-11P layer as the filler metal was successfully realized.

2021 ◽  
Vol 2083 (2) ◽  
pp. 022086
Author(s):  
Xiupeng Li ◽  
Yunyue Li ◽  
Sujuan Zhong ◽  
Yuanxun Shen ◽  
Weimin Long ◽  
...  

Abstract In this paper, a new type of AlSiMgCuNiAg filler metal was developed. The solidus temperature of the filler metal is 509.1°C and the liquidus temperature is 531.3°C. The filler metal has a good wetting and spreading effect on the surface of 6061 aluminum alloy. The CuAl2 phase in the brazing seam was greatly aggregated after brazed, while the CuAl2 phase was reduced and Mg2Si strengthening phase was formed when the brazed joints with heat treatment. The average shear strength of the brazed joint without heat treatment was 47.1MPa, and the average shear strength of the brazed joint with heat treatment reached to 108.7Mpa. The strength of the brazed joint with heat treatment was increased by about 131% relative to the strength of the brazed joint without heat treatment.


2015 ◽  
Vol 1101 ◽  
pp. 99-103
Author(s):  
Cheng Yen Wang ◽  
Ren Kae Shiue

The purpose of this research is focused on vacuum furnace brazing Incoloy 800 (IN-800) using the copper filler foil. Microstructural evolution and shear strength of brazed joints for various brazing conditions has been evaluated in the experiment. The Cu-rich matrix dominates entire brazed joint. The width of Cu-rich matrix is decreased with increasing the brazing temperature and/or time. Average shear strength of the joint is approximately 215 MPa. Dimple dominated fracture is widely observed for the specimen brazed below 1160oC. However, cleavage dominated fracture is found for the specimen brazed at 1200oC. It is advised that copper brazing IN-800 alloy should be confined below 1160oC.


Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 198 ◽  
Author(s):  
Peng Xue ◽  
Yang Zou ◽  
Peng He ◽  
Yinyin Pei ◽  
Huawei Sun ◽  
...  

The microstructure and properties of a Cu/304 stainless steel dissimilar metal joint brazed with a low silver Ag16.5CuZnSn-xGa-yCe braze filler after aging treatment were investigated. The results indicated that the addition of Ce could reduce the intergranular penetration depth of the filler metal into the stainless steel during the aging process. The minimum penetration depth in the Ag16.5CuZnSn-0.15Ce brazed joint was decreased by 48.8% compared with the Ag16.5CuZnSn brazed joint. Moreover, the shear strength of the brazed joint decreased with aging time while the shear strength of the AgCuZnSn-xGa-yCe joint was still obviously higher than the Ag16.5CuZnSn joint after a 600 h aging treatment. The fracture type of the Ag16.5CuZnSn-xGa-yCe brazed joints before aging begins ductile and turns slightly brittle during the aging process. Compared to all the results, the Ag16.5CuZnSn-2Ga-0.15Ce brazed joints show the best performance and could satisfy the requirements for cost reduction and long-term use.


2021 ◽  
Vol 1016 ◽  
pp. 522-527
Author(s):  
Anna Hashimoto ◽  
Shu Bin Liu ◽  
Ikuo Shohji ◽  
Tatsuya Kobayashi ◽  
Junichiro Hirohashi ◽  
...  

Electrodeposited Ni-11 mass%P alloy plating film was fabricated on the surface of stainless steel SUS304 to conduct brazing of SUS304 plates for a heat exchanger. Brazing of SUS304 plates with electrodeposited Ni-11P layers was carried out using a hydrogen reducing furnace. The microstructure and joint strength of the brazed joint were also investigated. From the result of the microstructural observation of the cross section of the joint, it was found that the brazing filler metal is homogeneously distributed without defects such as voids between the SUS304 plates. The results of electrochemical measurements showed that the P-concentrated phase in the Ni-11P alloy is preferentially dissolved in NaCl aqueous solution.


Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 283 ◽  
Author(s):  
Chieh Lin ◽  
Ren-Kae Shiue ◽  
Shyi-Kaan Wu ◽  
Huai-Li Huang

Infrared vacuum brazing of CoCrFeMnNi high entropy alloy (HEA) using BNi-2 and MBF601 fillers has been investigated. Both brazes show poor wettability at temperatures only 20 °C above their liquidus temperatures. However, the wettability of BNi-2 and MBF601 fillers on CoCrFeMnNi HEA is greatly improved with increasing the test temperatures, 50 °C above their liquidus temperatures. The BNi-2 brazed joints are dominated by Ni-rich matrix with huge CrB and a few tiny boride precipitates. Average shear strengths of joints increase with increasing brazing temperature and/or time, and fracture location changes from blocky CrB in the brazed zone to grain boundary boride in the substrate. The MBF601 brazed joints are composed of CoCrFeMnNi-based matrix, particles of B/Co/Cr/Fe/Mn/Ni/P compounds, and some phosphides form along the grain boundaries of the substrate. The specimen brazed with MBF601 filler foil at 1050 °C for 600 s has the highest average shear strength of 321 MPa, while that brazed at 1080 °C for 600 s has a lower average shear strength of 271 MPa due to the presence of solidification shrinkage voids.


1996 ◽  
Vol 458 ◽  
Author(s):  
Y. Morizono ◽  
M. Nishida ◽  
A. Chiba

ABSTRACTBonding characteristics and interfacial microstructures in explosively welded Ti/stainless steel clad of the as-welded and annealed states were investigated. In case of Ti/SUS430 ferritic stainless steel combination, the average shear strength of an as-welded clad was 555 MPa, and metastable phases such as amorphous and fine crystalline phases were observed at the interface. These were considered to be the trace of melting and subsequently rapid solidification at the contact surface of both the parent materials. By annealing below 1173 K, the strength gradually decreased with increasing holding time. The average shear strength of the clad annealed at 1073 K for 360 ks was 242 MPa, while that of the clad annealed at 1273 K abruptly decreased down to 107 MPa with increasing holding time up to 360 ks. The reaction layer formed at the interface consisted only of TiC in the former. On the other hand, the coexistence of TiC, TiFe, TiFe2 and χ was observed at the interface in the latter. The TiC in the former was considered to serve as a barrier for diffusion of Ti, Fe and Cr across the interface and to suppress the formation of intermetallic compounds. As a result, the growth of reaction layer was inhibited and high bonding strength was preserved even after prolonged annealing. The results of the Combination of Ti and SUS304 austenitic stainless steel were also discussed.


2005 ◽  
Vol 297-300 ◽  
pp. 2767-2771
Author(s):  
Ikuo Shohji ◽  
Satoshi Takayama ◽  
Takanori Nakazawa ◽  
Ken Matsumoto ◽  
Masanori Hikita

In the brazed joint of stainless steel with BNi-2 filler, brittle Cr-B compounds form in the vicinity of the centerline of the brazed joint. These compounds cause a decrease in joint strength. In this study, BNi-2 filler supplemented with Cr powder has been used in brazing stainless steel in orde r to disperse brittle Cr-B compounds uniformly in the brazed joint and improve joint strength. The mechanical properties and microstructures of the brazed joints were investigated. Moreover, a comp arison of the brazed joint with that using the BNi-2 filler was conducted.


2011 ◽  
Vol 418-420 ◽  
pp. 1242-1245
Author(s):  
Zhuo Jun Chen ◽  
Chang Jin Yang ◽  
Xiao Long Gu ◽  
Cheng Dong Wu ◽  
Long Long Feng

Vacuum brazing of 316L stainless steel with BNi-2 brazing filler metal.The effects of brazing temperature and brazing clearance on microstructure and mechanical properties of vacuum brazed joints of 316L stainless steel were studied. The results show that: As brazing temperature being 1 070 °C, with the increasing of the brazing clearance, the joint shear strength value become lower and lower. Brazing clearance compounds mainly contain intermetallic and solid solutions.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4216
Author(s):  
Shubin Liu ◽  
Ikuo Shohji ◽  
Tatsuya Kobayashi ◽  
Katsuharu Osanai ◽  
Tetsuya Ando ◽  
...  

In this study, an amorphous Ni-13.4Cr-11.6P (mass%) alloy coating with a thickness of 30 μm was deposited on the surface of SUS304 stainless steel as a brazing filler metal to conduct brazing. The differential thermal analysis measurements indicate that the electrodeposited Ni-13.4Cr-11.6P alloy has a melting point of approximately 892 °C, which is almost consistent with that of the commercial BNi-7 filler metal. The microstructure, shear strength, and fracture mode of the brazed joint were investigated using an electron probe X-ray microanalyzer, a scanning electron microscope, an optical microscope, and a universal testing machine. The results showed that the brazed filler metal is filled between the SUS304 stainless steel plates without any flaws in the brazed seam. The P-containing phases, i.e., the Cr-P rich phase and the (Ni,Fe)3P phase, were formed in the brazed seam. The shear strength of the brazed joint obtained in this study is 59.0 MPa. The fracture occurs in the brazed filler zone, where the brittle P-containing phases are present. Galvanic current measurement results showed that the brazed Ni-13.4Cr-11.6P alloy coating has a better corrosion resistance than that of the brazed Ni-11P alloy coating, which can be attributed to the formation of a large amount of Ni-Fe solid solution and Cr-P rich phase in the top layer of the brazed Ni-13.4Cr-11.6P alloy coating.


2016 ◽  
Vol 850 ◽  
pp. 700-705 ◽  
Author(s):  
Qian Qian Sun ◽  
Sheng Lu

The effects of brazing time on elements diffusion and bonding strength of vacuum brazed joints of 15-5PH stainless steel using filler metal BNi-2 were investigated. The results showed that the brazing time determined the content of diffused elements. If holding time is short the distribution of melting point depressants (MPD) concentrated on the middle zone of the joint, and the generation of brittle phases in the joint was unavoidable. With increasing time, MPD can diffuse to base metal adequately and full solid solution of nickel formed in the brazing joint. Joint strength firstly increased and then decreased with prolonging holding time.


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