Brazing Temperature Research Articles

Development of a new Mg–25Al–5Zn filler metal containing trace Y for brazing AZ91D magnesium alloy

In this work, the investigation focused on the effects of trace Y on the microstructure and characteristics of the Mg–25Al–5Zn filler metal, and then the optimal Mg–25Al–5Zn-0.5Y was used to braze the AZ91D magnesium alloy. Five kinds of filler metals showed good wettability on AZ91D magnesium alloy. Compared with Mg–25Al–5Zn filler metal, the wetting area of Mg–25Al–5Zn-0.5Y filler metal was increased by 134 % and the wetting angle was decreased by 58 %. This was mainly due to the spontaneous segregation of the active element Y at the interface. Thus, the surface tension was reduced and the wettability of the solder was improved. Different from the precipitation of α-Mg near the interface at different brazing temperatures, the distribution of α-Mg in brazing seam was more homogenous as the holding time increased. The microhardness of the brazing seam gradually increased from AZ91D side to the center of the brazing seam due to a lot of β-Mg17Al12 with high microhardness in joint. However, with the increase of brazing temperature and holding time, a large number of α-Mg solid solutions with low microhardness were precipitated in the brazing seam. As a result, the microhardness of the brazed joint gradually decreased. The shear strength of the brazed joint reached the maximum value (42 MPa) at 520 °C for 60 s. After calculation, the contribution of grain boundary strengthening and solid solution strengthening to shear strength was 67.98 % and 28.96 %, respectively.

Study on microstructure and mechanical properties of vacuum brazing TC4 titanium alloy with Ti-37.5Zr-15Cu-10Ni amorphous filler metal

Ti-37.5Zr-15Cu-10Ni amorphous brazing filler metal was employed to join TC4 titanium alloy by vacuum brazing. This work investigated the effect of brazing temperature and holding time on the interfacial microstructure and mechanical properties of TC4/Ti-Zr-Cu-Ni/TC4 joints. Results indicate that the increasing brazing temperature above 900 ℃ and prolonging the holding time both promoted the formation of α-Ti + (Ti, Zr)2(Cu, Ni) eutectoid phases and acicular Widmanstätten. The shear strength of joints increased with elevating brazing temperature and the maximum value was 223.9 MPa obtained at 940 °C. When prolonging the holding time at the brazing temperature of 900 ℃, the shear strength increased firstly and then dropped. When the brazing temperature was 900 °C, the microhardness in the reaction layer was highest, reaching 572 HV0.1, which was caused by the formation of (Ti, Zr)2(Cu, Ni) intermetallic compounds. As the brazing temperature rose to 940 °C, the microhardness in the reaction layer decreased to 427.5 HV0.1.

A novel method for reducing the brazing temperature of C/C composite with TiZrHfTa/Ni composite interlayers

C/C composite was successfully brazed with TiZrHfTa/Ni composite interlayers at lower temperature far below the melting point of TiZrHfTa refractory high entropy alloy. The influence of brazing parameters on the joint morphology, indentation fraction toughness of the reaction layer, shear strength at room temperature and at 1000 °C, and fracture behavior was investigated. The results show that all of the C/C composite joints contained two main phases: an equimolar (Ti-Zr-Hf-Ta)C hard phase and a near-pure Ni binder phase. The maximum indentation fracture toughness of the obtained joint reaction layer material was 15.52 ± 0.64 MPa·m1/2. This was proved to be beneficial to improve the strength and toughness of the joint. Meanwhile, the maximum shear strengths of C/C-TiZrHfTa/Ni-C/C joint at room temperature and at 1000 °C reached 33.24 ± 1.85 MPa and 21.70 ± 2.12 MPa, respectively. Abundant slip lines, in-situ dimples, and tearing ridges resulting from Ni plastic deformation suggest a predominantly ductile fracture mode in the joint. This work introduces an innovative method, which can not only ensure the service of C/C composite in high temperature environment, but also effectively reduce the joining temperature.

Interfacial microstructure and mechanical properties of CBN brazed in a continuous tunnel furnace with low-temperature Sn-Cu-Ti filler alloy

Currently, the most common process for manufacturing brazed cubic boron nitride (CBN) tools is vacuum brazing using Cu-based active filler alloys. However, the high brazing temperature of Cu-based alloys and the long heating time in a vacuum furnace inevitably cause severe thermal damage, thereby compromising the mechanical properties of the brazed CBN abrasives. In this study, CBN abrasives were brazed using low-temperature Sn-Cu-Ti filler alloys in a continuous tunnel furnace. The final contact angles of the Sn-Cu-Ti filler alloys on the surfaces of the brazed CBN abrasives were determined at 650 °C. When the Ti content in the alloy was 4 %, the final contact angle was 37.2° and the CBN maintained a good exposure height and achieved a firm holding force. The interfacial microstructure was analysed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). It was found that a layer of needle-like compounds, primarily comprising TiB2 and TiN, with an approximate thickness of 5 μm, was formed at the interface, indicating the formation of a chemical–metallurgical bond between the Sn-Cu-Ti alloy and CBN abrasive. The residual stresses and mechanical properties of brazed CBN abrasives with Sn-Cu-Ti and traditional Cu-based alloys were measured and compared. The results showed that compared to the brazed CBN with the Cu-based alloy, the average residual stress of the brazed CBN with the Sn-Cu-Ti alloy was reduced by 25.2 %, while the compressive strength and impact toughness increased by 25.3 % and 13.8 %, respectively. The experimental results provide new insights into reducing thermal damage to CBN for improving the processing performance of brazed CBN tools.

Effect of brazing temperature on microstructure and tensile strength of γ-TiAl joint vacuum brazed with micro-nano Ti−Cu−Ni−Nb−Al−Hf filler

A novel micro-nano Ti−10Cu−10Ni−8Al−8Nb−4Zr−1.5Hf filler was used to vacuum braze Ti−47Al− 2Nb−2Cr−0.15B alloy at 1160−1220 °C for 30 min. The interfacial microstructure and formation mechanism of TiAl joints and the relationships among brazing temperature, interfacial microstructure and joint strength were emphatically investigated. Results show that the TiAl joints brazed at 1160 and 1180 °C possess three interfacial layers and mainly consist of α2-Ti3Al, τ3-Al3NiTi2 and Ti2Ni, but the brazing seams are no longer layered and Ti2Ni is completely replaced by the uniformly distributed τ3-Al3NiTi2 at 1200 and 1220 °C due to the destruction of α2-Ti3Al barrier layer. This transformation at 1200 °C obviously improves the tensile strength of the joint and obtains a maximum of 343 MPa. Notably, the outward diffusion of Al atoms from the dissolution of TiAl substrate dominates the microstructure evolution and tensile strength of the TiAl joint at different brazing temperatures.

Effect of different joining temperatures on IN600/SiC brazed joints

IN600 superalloy and SiC ceramics has been conducted using an active AgCuTi filler, and the composite joints were characterized using scanning electron microscopy coupled with energy-dispersive x-ray spectrometry (SEM–EDS). The results demonstrate successful joining by carefully selecting brazing temperatures and holding times to produce high-integrity joints. The interfacial microanalysis revealed the formation of TiC and Ti5Si3 near the SiC side due to the reaction between titanium, carbon, and silicon. On the IN600 superalloy side, a Ti-Ni compound (TiNi3) was formed as a result of titanium reacting with nickel. The typical microstructure of the brazing joint interface includes: TiC+TiNi3, TiC, Cu(s,s)+Ag(s,s) and TiC+Ti5Si3. Furthermore, the shear strength evaluation of the joints was also conducted at ambient temperatures using a shear test. The experimental findings showed that the sample exhibited the highest shear strength (38 MPa) when subjected to brazing at 910 °C for 10 min. Fracture occurred at the interface between the base material and AgCuTi filler at higher brazing temperature (930 °C).

Strengthening Ti3SiC2/Cu brazed joint assisted with cold spray additive manufacturing: Lower brazing temperature through interdiffusion and graded reinforcement for stress relaxation

Graded composite fillers exhibit unique advantages in alleviating residual stress in ceramic/metal brazed joints. However, traditional methods for preparing graded composite fillers are often complex and may deplete their strengthening phases. In this study, cold spray additive manufacturing was employed to fabricate yttria-stabilized zirconia (YSZ)-Ti25Zr25Ni25Cu25-Ag graded composite coatings on Cu substrates to serve as fillers. The graded composite coatings and the resultant Ti3SiC2/Cu brazed joints were systematically characterized to elucidate the deposition mechanism of the coatings and its residual stress-relaxed mechanism. The bondings between particles in the coatings, based on their plastic deformation ability, were classified into noncrystalline weak bonds and homogeneous strong bonds. Both bondings facilitated the elemental interdiffusion between filler and Cu substrate during the heating process, which contributed to the formation of Ag-Cu eutectic. This significantly reduced the required brazing temperature and its induced residual stress. Furthermore, the solid phase transformation of graded-distributed YSZ within the brazing seam from tetragonal to monoclinic achieved a smooth thermal transition and releasing residual stress at the same time. Consequently, the shear strength of the brazed joint reached to the highest value of 110.23 ± 3.45 MPa, which was Much higher than the previously reported values. This study introduces a novel method for residual stress relaxation assisted with cold spray technology and broadens its application in the brazing field.

Brazing of Copper Foam Using Cu-4.0Sn-9.9Ni-7.8P Filler Foil: Effect of Brazing Temperature and Copper Foam Pore Density

Copper (Cu) foam is a promising material that owns a high surface area that can be utilized in a thermal application. In this research, the brazing of Cu substrate to Cu foam in the sandwich configuration using Cu alloy filler foil was carried out. The foam at different pore per inch (PPI) of 15, 25 and 50 are brazed at different brazing temperatures. Mechanical and microstructure analysis were conducted to investigate a suitable brazing temperature and the best pore density of foam. The compressive strength of brazed 50 PPI foam has yielded the highest due to the highly dense interconnected branches. While the highest shear strength of brazed interface using 15 PPI foam has been recorded. The large branch size of 15 PPI foam has contributed to the sound joint between the brazed joint interface of Cu substrate and foam. Both mechanicals analysis above exhibits a highest strength at 660 °C as a brazing temperature The shear stress-strain curve of Cu substrate and foam brazed joint interface shows a brittle behaviour which accordance with the discoverable brittle phases of Cu3P and Ni3P using X-ray diffraction (XRD). Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX) have presented the formation of Cu3P and Ni3P at the brazed joint interface of Cu substrate and foam.

Numerical investigation of deformation and residual stress in vacuum brazing of titanium alloy plate-fin structure

Various high-end equipment relies on titanium alloy plate-fin structure (PFS) as core components, owing to their remarkable advantages in terms of low density, superior mechanical strength and enhanced corrosion resistance. Brazing assumes a pivotal function in PFS connections, whereby the localized concentrated heat during the welding procedure can precipitate intricate structural deformation and generate residual stresses. A thermo-mechanical coupling model was developed, taking into account the service performance criteria of PFS. The effects of process parameters and clamping methods on the post-welding residual stress and deformation of PFS were investigated. The analytical expressions for the relationship between the process parameters and the stress/deformation were obtained by using the simulation outcomes. The constraint on the partition in the vacuum brazing process determines the extent of deformation and residual stress of PFS, with higher constraint leading to lower values. PFS generates z-directional displacement and y-directional warping deformation, and the weld seam between the fin and the partition is prone to stress concentration. As the brazing temperature and holding time increase, the PFS induces more deformation, while the residual stress value decreases. However, the deformation amount reaches a plateau when the holding time exceeds 30 min.

Optimization of brazing parameters for 316L stainless steel with AgCuZn filler metal under argon atmosphere

This research studies the optimal parameters for brazing 316L stainless steel using AgCuZn as filler metal under an argon gas atmosphere. The brazing parameters included temperature, brazing time, and argon gas flow rate. The study employed Box-Behnken design for experimental design and desirability function as the optimization tool. Mechanical properties study included the measurements of shear force, microhardness, microstructure, and fracture of brazing joints through a scanning electron microscope (SEM) as well as the chemical composition using an energy dispersive x-ray spectroscopy (EDS). As a result, the temperature and the brazing time significantly affected the shear force of the brazed joint at a 95 percent confidence interval. The optimal condition of the study was 800°C of temperature and a 20-minutes brazing time which caused the maximum shear force at 5,909.1 N. The brazing joint strength was increased when the temperature and time of brazing were increased and reached the optimal point. Microstructure showed a formation of an Ag-rich phase, a Cu-rich equiaxed dendrite phase, and a eutectic Ag-rich phase, which completely combined as the network structure and evenly small fine grains. Moreover, the shear force of the brazed joint was decreased when the temperature and time of brazing exceeded the optimal point due to the grain growth of the interface layer.

Brazing of high-nitrogen steel to Al0·3CoCrFeNi using a BNi-2 filler: Microstructure, mechanical properties, and corrosion resistance

Studies that focus on brazing high-nitrogen steel (HNS) to high-entropy alloys (HEAs) are currently limited. In this study, the HEA Al0·3CoCrFeNi was successfully brazed to HNS using a commercial BNi-2 filler at 1080–1140 °C. The microstructure and shear strength of the Al0·3CoCrFeNi/HNS brazed joints were observed and evaluated. The typical microstructure of the brazed joint was HNS/infiltration layer/reaction layer/Ni(s,s) (containing NiAl3)/reaction layer/infiltration layer/Al0·3CoCrFeNi. The higher brazing temperature and longer holding time promoted the diffusion of B as a brazing seam with homogeneous Ni(s,s), and more intergranular Cr-rich borides formed in the base materials. The optimized shear strength attained 549.2 MPa after the joint brazed at 1120 °C for 15 min, and ductile fracture occurred in the reaction zone. The insufficient and excessive diffusion of B resulted in residual Cr–B compounds in the brazing seam and excess borides in the HNS, respectively, which negatively affected shear strength. All the joints showed poor corrosion resistance following immersion in a 3.5 wt% NaCl solution because the excess Cr-rich compounds resulted in decreased Cr content in the surrounding matrix. Therefore, Ni-based fillers without B were more suitable for obtaining Al0·3CoCrFeNi/HNS joints with a favorable corrosion resistance.

Microstructure evolution and mechanical properties of SiC and Nb joint brazed with AgCuTi/(Sr0.2Ba0.8)TiO3–Cu/AgCuTi composite fillers

In this study, robust silicon carbide (SiC)-niobium (Nb) joints were obtained using a composite filler consisting of a novel type of negative thermal expansion (Sr0.2Ba0.8)TiO3 particle–reinforced Cu composites (SBT-Cu) and an AgCuTi active filler. A systematic investigation was conducted to analyze the brazing temperatures and SBT-Cu thickness affect the microstructure and mechanical properties of brazed joints. The results indicated that the shear strength of SiC–Nb joints brazed with AgCuTi +80 μm SBT-Cu composite filler increased to 64 MPa at 900 °C for 15 min, which was an improvement of 146 % over the strength of joints brazed without SBT-Cu. The addition of the SBT-Cu interlayer relieved the coefficient of thermal expansion mismatch among SiC, AgCuTi and Nb. Meanwhile, the calculation results verified that the residual stresses in the joints were substantially reduced and that the coefficient of thermal expansion of the composite filler was reduced.

Ag-based filler metal wetting behavior and brazed joint performance on SLMed Ti/TiB2 substrate

PurposeThis study aims to investigate the wetting behavior of AgCuTi and AgCu filler metals on selective laser melting (SLMed) Ti/TiB2, and to analyze the microstructure and fracture characteristics of SLMed Ti/TiB2/AgCuTi or AgCu alloy/SLMed Ti/TiB2 brazed joints. The wetting behavior of AgCuTi and AgCu filler metals on the selective laser melted (SLMed) Ti/TiB2 has been studied. The analysis of microstructures and fracture characteristics in vacuum-brazed SLMed Ti/TiB2 substrate, using AgCuTi and AgCu filler metals, has been conducted to elucidate the influence of brazing temperature and alloy composition on the shear strength of the brazed joints.Design/methodology/approachBrazing SLMed-Ti/TiB2 in a vacuum using AgCuTi and AgCu filler metals, this study aims to explore the optimal parameters for brazed joints at various brazing temperatures (800°C−950°C).FindingsThe findings suggest that elevated brazing temperatures lead to a more extensive diffusion region in the joint as a result of the partial melting of the filler metal. The joint composition changes from distinct Ti2Cu layer/TiCu layer/filler metal to a-Ti (ss) + ß-Ti (ss)/TiCu. As the brazing temperature increases, the fracture mode shifts from brittle cleavage to ductile fracture, mainly attributed to a decrease in the CuTi within the brazed joint. This change in fracture behavior indicates an improvement in the ductility and toughness of the joint.Originality/valueThe originality of this study lies in the comprehensive analysis of the microstructure and shear strength of vacuum brazing SLMed Ti/TiB2 using AgCuTi and AgCu filler metals.

Achieving ultrafine grain strengthening Cf/SiC-GH3536 joints brazed with Cu-Ti-WC composite interlayer via cold spray additive manufacturing

Cold spray additive manufacturing (CSAM), as a solid-phase additive manufacturing technology, exhibits enormous potential in the fabrication of metal matrix composite. The conventional preparation methods of composite filler often have some problems, such as agglomeration of reinforcements and poor fluidity, which have limited the further application of composite filler. In this study, we proposed a novel method to prepare the Cu-Ti-WC composite interlayer for brazing Cf/SiC and GH3536 using CSAM. The synergistic deposition mechanism of matrix particles and reinforcing particles in the composite interlayer was revealed. The deformation and recrystallisation of Cu and Ti particles and the crushing and tamping of WC particles achieved the deposition of the cold sprayed Cu-Ti-WC interlayer. The CSAM achieved a tight bonding of the composite filler, generating the initial TiC before reaching the brazing temperature. And the Fe-W-Ni-Cr-Cu multi-principal element alloys (MPEA) generated from the reaction between WC and Cr(s,s), and formed ultrafine grain regions (∼200 nm) with [2–1 −1 0]HCP-MPEA // [0 0 1]TiC and [-1 1 1]FCC-MPEA // [1 1 3]TiC orientation due to the hindering effect of the increased TiC. The shear strength of Cf/SiC-GH3536 joint brazed with cold sprayed Cu-Ti-WC interlayer was improved to 112.0 MPa, which is 1.5 times higher than that of Cu-Ti-WC powder filler. This study shows the great potential of CSAM in fabricating metal-based composite interlayers for brazing and aids in composite-metal joining for higher performance.

Microstructure and properties of C/C and C/SiC composites brazed by reactive infiltration of Si[sbnd]Zr filler alloy

The joint between C/C composites and liquid silicon infiltrated-C/SiC composites was achieved using a Si10Zr (at. %) eutectic filler. The microstructure and mechanical properties of joints at different brazing temperature and holding time were characterized. The results showed that the melting filler infiltrated along the carbon fiber bundle gaps and formed SiC reaction layers at both interfaces. On the side of C/SiC composites, the residual silicon in the original base material dissolved into the molten Si10Zr alloy during the brazing procedure. The phenomenon resulted in intense infiltration of the liquid filler into C/SiC composites, which formed a unique C/SiC-Si-ZrSi2 multiphase-ceramic gradient structure. Excessive filler was squeezed out around the joint seam to form a fillet. The shear strength of the joint reached up to 37 MPa, with fracture occurrence in both substrates and the joint seam. Reliable bonding between C/C and C/SiC dissimilar composites was finally achieved.

Interface bonding characteristics and thermal damage behavior of brazed diamond with Nb-added Ni[sbnd]Cr filler alloys

NiCr alloy is one of the important filler for brazed diamond tools because of its high hardness, high wear resistance and good wettability to diamond. However, the high brazing temperature and catalytic action of Ni element contained in alloy tend to cause the thermal damage of diamond and interface failure of brazed samples. In this work, the noval NiCr filler alloys added with different contents of Nb are prepared, and the microstructures, mechanical and wear resistance properties of brazed layers used these alloys are investigated. On this basis, the interfacial bonding characteristics and thermal damage behaviors of diamond brazed with Nb-added NiCr filler alloys are further studied. The results show that the addition of Nb element improves the hardness and wear resistance of NiCr filler layer, and the filler alloys exhibit good wettability and climbing effect to diamond. The refined Cr3C2 and Cr7C3 carbides are formed on the surface of diamond, which effectively enhances the interface bonding strength between filler alloy and diamond. Meanwhile, the addition of Nb element consumes some Ni and generates NbNi compound, which weakens, to some extent, the graphitization catalysis and chemical erosion of Ni to diamond. When the addition amounts of Nb are 1–1.2 wt%, the brazed diamond samples present excellent interfacial bonding strength and mechanical properties.

Wettability and joining of reaction-bonded silicon carbide (RBSC) by Ti–Si eutectic alloy

The high-strength joining of reaction-bonded silicon carbide (RBSC) is pivotal for its application in the semiconductor field. In this paper, the wetting and joining mechanism of Ti–Si eutectic alloy on RBSC were investigated. The contact angles observed between Ti–Si eutectic alloy and RBSC were approximately 1.9°, indicating the favorable wettability and demonstrating the feasibility of bonding RBSC joints. The temperature bending strength of the joints initially increased and then decreased as the brazing temperature increased. Moreover, the shear strength of approximately 107.38 ± 5.56 MPa was achieved at 1350 °C for 30 min. Notably, the diffusion and amalgamation of atoms, lead to the establishment of stronger bonds between adjacent particles. Thus, the Ti–Si eutectic alloy brazing filler formed a direct connection with the RBSC matrix, with Si2Ti infiltrating into the base metal on both sides. The utilization of Ti–Si eutectic alloy brazing filler in RBSC joints exhibits promising prospects.

Varying interfacial reaction patterns in (VNbTaMoW)C ceramic joints brazed with Ti-Zr-Ni-Cu filler alloy

The brazing of (VNbTaMoW)C ceramic with TiZrNiCu active filler is systematically studied. The metallurgical connection relies on two temperature-dependent patterns of interfacial reactions. At a low brazing temperature of 900°C, active Zr dominates interfacial reactions by seizing C atoms in HETMC lattice, generating a continuous (Zr, Ti, Nb)C layer and leading to the transformation of HETMC into a non-stoichiometric HETMC'. The continuous reaction layer is the weak area of joints, resulting in a shear strength of only 83 MPa. The interfacial reaction pattern becomes dominated by active Ti as the brazing temperature is increased. The continuous (Zr, Ti, Nb)C layer is transformed into a flocculent (Zr, Ti, Nb)C′ and partial HETMC' is decomposed into high-entropy intermetallic and (Ti, Nb, Ta, Zr)C particles. The improved interfacial structure enhanced the load-bearing capacity of joints, enabling the joint obtained at 980°C for 10 min to deliver the highest shear strength of 193 MPa.

Brazing Temperature Effects on the Microstructure and Mechanical Properties of Ti-45Al-8Nb Joints Using TiZrCuNi Amorphous Interlayer

Ti-45Al-8Nb alloy is widely utilized in the lightweight design of the aerospace field because of its excellent properties. In order to make full use of this alloy, it is important to carry out relevant research, such as into the joining process of Ti-45Al-8Nb alloy. In this work, Ti-45Al-8Nb alloys were successfully connected by a TiZrCuNi amorphous interlayer, which was fabricated using the rapid solidification method. Ti-45Al-8Nb joints were composed of two zones. The typical microstructure of a Ti-45Al-8Nb joint was Ti-45Al-8Nb/AlCuTi + Ti3Al/(Ti, Zr)(Cu, Ni) + (Ti, Zr)2(Cu, Ni)/Ti3Al + AlCuTi/Ti-45Al-8Nb. The diffusion of elements between the interlayer and the substrate was enhanced by increasing the brazing temperature, which resulted in an increase in the thickness of the interfacial reaction layer. The maximum shear strength was 171.2 MPa, which was obtained at 930 °C. The typical cleavage fracture was found in all of the Ti-45Al-8Nb joints. The mechanical properties of the joint were compromised at high brazing temperature due to the presence of excessive (Ti, Zr)2(Cu, Ni) phase and coarse Ti3Al phase, both of which are inherently brittle and harmful to the shear strength of the obtained joint.

Brazing of Copper Pipes for Heat Pump and Refrigeration Applications

In heat pumps and refrigeration systems, copper parts play a crucial role. Since heat pumps for space and water heating work under high pressure and are susceptible to vibrations, it is crucial to perfectly weld the copper pipes and heat exchangers to avoid system failures and prevent the leakage of the circulating refrigerants, which are harmful to the environment. The welding of the copper pipes is usually performed by the brazing process in a furnace. The components are subjected to a period of approximately 50 min inside a continuously open oven, varying the temperature from 710 °C to 830 °C. The oven inlets and outlets are protected by nitrogen curtains to guarantee a suitable internal environment and prevent the contamination of the gas inside the oven. This work analyses which welding methods are most suitable for welding copper, the best joint shape, process time, brazing specimens of a copper alloy, tightness tests, and mechanical properties and composition of the welding samples. From the tests carried out, the appearance of small and large defects is reduced by using a 1 mm thick external ring of filler material and a brazing temperature of 820 °C.