Vacuum Brazing of Copper Tubes Using Ag-Cu Filler

2013 ◽  
Vol 690-693 ◽  
pp. 2664-2667
Author(s):  
Rui Feng Li ◽  
Zhong Xing Shi ◽  
Kai Qi ◽  
Ming Fang Wu

Joining of copper tubes using Ag-Cu filler has been carried out by vacuum brazing technology. The microstructure and mechanical property of brazed joints were studied by means of metallography, optical microscope (OM) and universal tensile test machine. Experimental results show that failure occurs in the base metal and the tensile strength can reach 179 MPa. The optimal vacuum brazing parameters are: brazing temperature 820 °C, vacuum level 10-3Pa and holding time 5 min.

2006 ◽  
Vol 532-533 ◽  
pp. 564-567
Author(s):  
Jun Min Li ◽  
Fu Rong Chen ◽  
Jun Liu ◽  
Rui Jun Xie ◽  
Gang Hu

By means of optical microscope(OM), scanning electron microscope(SEM), X-ray diffraction(XRD) and shear test, the microstructure and mechanical property of 1Cr18Ni9Ti stainless steel brazed joints with BNi-2 filler by electron beam brazing(EBB) and vacuum brazing(VB) are investigated respectively. The results show that, the microstructures of brazed joint with BNi-2 by EBB are mainly solid solutions of Ni. And the microstructures of brazed joint by VB are composed of two parts: one part is a solid solution of Ni, which lies adjacent to base metal; another part is chemical compound structures present in the centre zone of brazing seam. The shear strength of brazed joint by EBB is higher than that of by VB. This is closely related with the microstructures of brazed joint.


2004 ◽  
Vol 449-452 ◽  
pp. 305-308
Author(s):  
Lei Wang ◽  
Toshiro Kobayashi ◽  
Chun Ming Liu

Tensile test at loading velocities up to 10 m·s-1(strain rate up to 3.2x102s-1) was carried out forr SiCp/AC4CH composite and AC4CH alloy. The microstructure of the composite before and after tensile deformation was carefully examined with both optical microscope and SEM. The experimental results demonstrated that the ultimate tensile strength (UTS) and yield strength (YS) increase with increasing loading velocity up to 10 m·s-1. Comparing with AC4CH alloy, the fracture elongation of the composite is sensitivity with the increasing strain rate. The YS of both the composite and AC4CH alloy shows more sensitive than that of the UTS with the increasing strain rate, especially in the range of strain rate higher than 102s-1.


2005 ◽  
Vol 488-489 ◽  
pp. 161-164
Author(s):  
Honghui Zou ◽  
Xiao Qing Zeng ◽  
Chun Quan Zhai ◽  
Wen Jiang Ding

Microstructure and mechanical property changes brought by the addition of Nd element in Mg-5wt%Zn-2wt%Al alloy are investigated, results show Al element takes a priority to react with Nd element over Mg and Zn, forming binary phases Al2Nd or Al11Nd3, tensile test showed that the total elongation is improved by the addition of Nd, and the UTS is also elevated when the Nd content surpass 1wt%. With a larger Nd addition, the phase dominating grain boundary is Al11Nd3 phase.


Author(s):  
Sijing Fu ◽  
Binghua Jiang ◽  
Jing Wang ◽  
Hong Cheng

In this paper, near net shape casting technology was used to manufacture Cr12MoV steel die modified using RE-Ti. The samples with different RE(rare earth)-Ti content were fabricated by using the induction furnace. The microstructure of the samples was analyzed by using optical microscope and scanning electron microscope. Electronic universal tensile test machine, pendulum impact tester and rockwell apparatus were utilized to test the mechanical properties of the samples. The results show that after RE-Ti compound modification, the distribution and morphology of carbide are improved, and with the Ti increase, the impact toughness significantly increases, and tensile strength has a slight increase, but hardness is almost unchanged. When Ti content is 0.6%, the impact toughness and tensile strength are 14.9 J/cm2 and 634 MPa, respectively, reaching or approaching to the mechanical properties of the forged Cr12MoV steel.


2013 ◽  
Vol 423-426 ◽  
pp. 693-698 ◽  
Author(s):  
Qun Qin ◽  
Guang Xia Chen

The objective of the research was that analyzed the microstructure and mechanical properties of metal part built by SLM in this paper. The tensile samples were made by SLM, the rupture gotten with tensile experiment was scan by SEM, and the rupture property was analyzed. The results of experiment showed: the parts formed by optimized parameters have a density above 96%, a tensile strength of 635MPa, an extension of 55.679% and an average micro hardness of HV307 for stainless steel powder. It is interesting to find that the phase of the built parts is also austenite by XRD, which is the same as that of the starting material.


2019 ◽  
Vol 805 ◽  
pp. 59-64
Author(s):  
Achmad Chafidz ◽  
Cholila Tamzysi ◽  
Lilis Kistriyani ◽  
Ratna Dewi Kusumaningtyas ◽  
Dhoni Hartanto

PP/clay nanocomposites samples of 1st and 2nd cycles (recycle) and different nanoclay loadings (i.e. 0, 5, 10, 15 wt%) samples were made by utilizing twin-screw extruder and injection molding machine. The samples were then characterized using a tensile test machine. The tensile tests results showed that modulus of elasticity and tensile strength of the nanocomposites samples for both 1st and 2nd cycles were all higher than the neat PP, and increased with increasing nanoclay loadings. The enhancements of modulus of elasticity (as compared to the neat PP) for 1st cycle of the nanocomposites were about 38.08%, 49.33%, and 78.65% for NC-5-I, NC-10-I, and NC-15-I, respectively. Whereas, for the 2nd cycle of the nanocomposites were about 44.33%, 59.59%, and 84.69% for NC-5-II, NC-10-II, and NC-15-I, respectively. This indicated that the incorporation of nanoclay in the PP matrix significantly increased mechanical properties, especially modulus of elasticity and tensile strength of the nanocomposites. Additionally, values of modulus of elasticity and tensile strength of 1st cycle and 2nd cycle of PP/clay nanocomposites were compared by plotting them in two graphs. The plots revealed that reprocessing of the nanocomposites did not significantly influence the mechanical properties of the nancomposites.


2009 ◽  
Vol 24 (3) ◽  
pp. 636-640
Author(s):  
Ling-Yan ZHANG ◽  
Ming-Li QIN ◽  
Xuan-Hui QU ◽  
Yan-Jie LU ◽  
Xiao-Yong ZHANG

2006 ◽  
Vol 519-521 ◽  
pp. 425-430 ◽  
Author(s):  
Keiyu Nakagawa ◽  
Teruto Kanadani ◽  
Kenich Nakayama ◽  
Akira Sakakibara

In this study, we investigated the effects of a small addition of Cu (0.1%) or Ge (0.1%) on the microstructure and mechanical property of Al-Si alloys. The results are as follows. The size of precipitates in the Cu-added or Ge-added alloys is smaller than that in the binary alloy. The size of the precipitates at the grain boundary in the Cu-added or Ge-added alloys is larger than the size of the precipitates in the binary alloy. However, the number of the precipitates at the grain boundary in the Cu-added and Ge-added alloys is smaller than that in the binary alloy. It was found that a small addition of Cu or Ge has the effect of raising the fatigue strength under repeated tensile loading as well as the tensile strength.


2016 ◽  
Vol 701 ◽  
pp. 154-158
Author(s):  
Nurul Hidayah Othman ◽  
Norsyahfiana Abdul Razak ◽  
Luqman Hakim Ahmad Shah ◽  
Mahadzir Ishak

This study focuses on the effect of pin taper tool ratio on friction stir welding of aluminum AA7075. Two pieces of AA7075 alloy with thickness of 6 mm were friction stir welded by using conventional milling machine. The shoulder diameter used in this experiment is fix 18mm. The taper pin ratio used are varied at 6:6, 6:5, 6:4, 6:3, 6:2,and 6:1. The rotational speeds that were used in this study were 1000 rpm, 1200 rpm and 1400 rpm, respectively. The welding speeds used are 60 mm/min, 80 mm/min and 100 mm/min. Microstructure observation of welded area was studied by using optical microscope. To evaluate the mechanical properties of this specimen, tensile test was used in this study. Welded specimens using taper pin ratio 6:2 shows higher tensile strength compared to other taper pin ratio up to 197 MPa. Moreover, taper pin ratio 6:1 showed better tensile test compared to taper pin ratio above 6:3. The optimum parameters were found to be taper pin ratio 6:2 with 1000 rpm of rotational speed and 60mm/min welding speed.


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