Copper Filler Research Articles

Study on the Microstructure and Mechanical Properties of Butt GMAW Al/Fe Dissimilar Joints using Pure Copper Filler Metal

The automobile industry is required to reduce the automotive exhaust emissions and enhance fuel efficiency by reducing the weight of the vehicle body (lightweight body) and increasing the strength of the vehicle. To manufacture a lightweight body, there have been numerous studies on Al/Fe dissimilar joining globally. However, the biggest problem of those studies was the formation of the Al-Fe intermetallic compound (IMC) layer, which broke the weld metal on the Al-Fe IMC layer. Therefore, in this study, Al/Fe dissimilar joining using gas metal arc welding using pure copper (Cu) filler metal was proposed to solve the aforementioned issues. As the travel speed increased 5 to 9 mm/s, the temperature gradient and crystal cooling rate increased. This made the Al-Cu Eutectic and Hypereutectic Zone to be narrow and dendrite α-Al Zone to be wide in the Al-based weld zone (Weld Zone Ⅱ). From the travel speed of 8 mm/s, the hardness at the Weld Zone Ⅱ is lower than the under the travel of 7 mm/s. The tensile test results for fracture was observed in the Al base metal.

Mechanical And Metallurgical Investigation Of Tig Welded-Brazed Aluminum And Stainless Steel Disimilar Joint By Using Copper Filler Rod

Automobile bodies made by mix of steel and aluminum composites are getting famous in present days to decrease weight. Present work means to exhibit the strength of Aluminum and steel welded joint. Primary measures centered in this work are strength forecast, streamlining of welding measure boundaries and investigation of intermetallics. Base materials utilized are AA6061 aluminum alloys and SS304 hardened steel alloy. BCuP-4 copper filler bar is utilized for TIG welding/brazing of base metals. Taguchi L27 symmetrical exhibit with three elements is taken for plan of analyses. Analysis of Variance (ANOVA) a tool used to determine a remarkable effect of welding parameters and their performance significantly. In addition, experimental Tensile strength is compared to predicted values based on ANN. The results were found to be satisfactory. Formation Of IMCs were studied by doing SEM analysis.

Effects of copper fillers on mechanical and electrical properties of selective laser sintered PA 12-Cu composites

ABSTRACT Selective Laser Sintering (SLS) is a widely used additive manufacturing (AM) technique for creating 3D geometries by adding materials in layers. Although neat polymer is mainly used in powder forms for production, organic or inorganic fillers can be added to produce polymer composites by SLS method. In this study, Polyamide 12 (PA 12) matrix composite parts filled with two different copper particles, dendritic and spherical shaped, were produced, and their mechanical, structural and electrical properties were investigated. The present study outlined that by increasing incident energy densities during sample fabrication, changes in mechanical and electrical characteristics were examined. The findings were analysed in terms of filler type and energy input, which were discovered to have a slight change in the bending behaviour of SLS components. Furthermore, the impact strength was shown to increase constantly with increasing energy density. Furthermore, whereas the electrical conductivity of spherical Cu-filled parts rose considerably, no significant change was seen in dendritic-shaped Cu-filled parts.

Silicon solar cells and modules with front contact paste containing copper‐based component

AbstractIn this article, we present the results of aging tests of silicon photovoltaic modules with a copper‐containing electrode deposited in one‐step screen printing method. For front metallization, a mixture of commercial silver paste with copper filler was used, where copper constituted 30% of total paste volume. The filler is based on copper particles about 1 μm of diameter covered with a protective coating layer based on nickel (CCu1) or nickel–silver (CCu2). For the first time, Si solar cells with screen‐printed front electrode containing massive copper with efficiency over 20% are reported. Aging tests included 2000 h of damp heat (DH) and 400 times of thermal cycling (TC) tests. TC results are very promising and provide slight deterioration of the electrical parameters of the modules with both CCu1 and CCu2. Greater decreases were found when performed DH tests, but it is worth pointing out that mainly fill factor (FF) and η have fallen while Voc and Isc did not change by more than 5% for both pastes. After 2000 h of the test, FF decreased by 28% for CCu1 and 37.4% for CCu2, whereas the efficiency deteriorated by 32% and 42.6% for CCu1 and CCu2. The electroluminescence (EL) and X‐ray photoelectron spectroscopy (XPS) measurements suggest that decrease in electrical parameters is a consequence of Cu corrosion caused by harmful products of the decomposed EVA laminating film.

Microstructural Evaluation of Copper Brazed Joints Using Silver-Based Filler Metal

The oxy-acetylene torch brazing of copper tubes using silver-based filler metals (Ag-Cu-Zn-Cd) was investigated in this study. Filler metals containing silver content of 15% and 35%, designated by BR15 and BR35, were used to assess the influence of the silver content in the microstructure and mechanical performance of brazed joints. The brazed joints microstructure was analyzed by means of optical microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The microstructures of the BR15 and BR35 samples were composed mainly of Ag–Cd-rich phase, solid solution of Cu–Zn, and a eutectic structure of Ag and Cu. The increase in the Ag content changed the solidification mode from cellular to dendritic and caused an increase in the eutectic phase volume fraction. The tensile strength of the Ag–Cu–Zn–Cd filler and the phos–copper filler metals was compared. The tensile strength of silver-based filler metal was slightly higher than the phos–copper filler metal brazed joints.

Thermal-Transient Analysis for Cooling Time on New Formulation of Metal Epoxy Composite (MEC) as Mold Inserts

In injection molding process (IMP), the cooling phase is greatly affected by thermal conductivity as the main factor for conductive heat transfer which represents about 70–80% of the cycle time. Recently, most researchers focus on overcoming the limitation with regard to poor thermal conductivity by developing a new formulation of metal epoxy composite materials as mold inserts for rapid tooling (RT) in IMP. Thus, this research investigates the performance of the cooling efficiency of mold inserts fabricated using epoxy resin mixed with filler particles consisting of aluminum, brass and copper. The transient thermal analysis carried out using the ANSYS simulation software was used to evaluate cooling performance of mold inserts made from various types of filler particles mixed with epoxy. The results obtained will be compared with the results of using P20 mold steel, which is the common material used as mold insert for RT. The simulation results showed that inserting a copper filler particle in the epoxy mold inserts was able to improve the efficiency of cooling time and definitely improve the cycle time of IMP. It is expected that a better mold insert in terms of cooling efficiency could be produced using RT technologies, thus, offering more profit to the molding industries without compromising the quality of molded parts produced.

About the Features of Electric Conductivity Models for Polymer Composite Nanomaterials Based on Cu(Cu2O)-LDPE

Polymer nanocomposites based on Cu(Cu2O)-LDPE with a volume fraction of 0.1–0.4 copper filler in the form of spherical nanoparticles with sizes from 10 to 25 nm were synthesized. The electrical conductivity of such composite nanomaterials was measured, which is 4.5–5 times higher than the electrical conductivity of a polyethylene matrix. To predict the electrical conductivity of such materials, an analysis of well-known mathematical models is carried out and models for predicting the electrical conductivity of such materials are selected that are adequate to the experimental data.

Strength of resistance spot welding of aluminum alloy AA6061 to carbon steel using different filler materials

Resistance spot welding is a process in where contacting metal surfaces for similar or dissimilar materials are joined by heat generated from resistance to electric current. Carbon steel and aluminum alloy A6061 sheets were welded by using resistance spot welding method in two stages with and without filler materials where copper and zinc were implemented as fillers, where those two materials, particularly the former, has acceptable affinity, therefor better wettability, to both welded metals. The characteristics of weld joint were investigated by measuring the effect of welding current and time on the nugget size and tensile shear strength of the weldment. The results showed that the welding current has an incremental influence on both the nugget size and tensile shear strength for the two cases studied. Also, the results revealed that the copper filler increases the strength of the weldments more than the zinc filler, which is attributed of higher affinity of the copper to both metals. The joint with the maximum tensile shear strength of 47 kN/m2 is obtained at the condition of 15 kA welding current for copper filler and 40 kN/m2 is obtained at the condition of 13 kA. The thickness of interfacial reaction layer decreased from central joints region to the surrounding area.

Electroless nickel underlayer deposited between copper filler and silicon substrate: effect of bath pH

ABSTRACT This research proposed intermediate materials between Cu filler and Si wafer to reduce the coefficient of thermal expansion (CTE) mismatch in the through silicon via (TSV) structure. The proposed material is Ni underlayer because it has CTE value between Cu and SiO2 which is 13 ppm/°C (Cu = 17 ppm/°C, SiO2 = 0.6 ppm/°C). The deposition process of nickel underlayer was conducted using electroless deposition process at various pH value (4.5, 5.5 and 6.5) of plating bath and deposition time (20, 40 and 60 minutes). The deposition behaviour was studied through surface and cross-sectional analysis under scanning electron microscopy (SEM). The Ni thickness was measured using cross-sectional analysis under SEM. The chemical composition of Ni deposits was measured using energy dispersive spectroscopy equipped on SEM. The performance test analysis was conducted using Standard ASTM D3359 (Cross Hatch Tape-Test) for coating adhesion test and 4-Point Probe Test for resistivity measurement. It was found that the optimum pH of the Ni bath is 6.5 due to high stability of plating bath to form uniform Ni deposited on silicon wafer. These optimum coating parameters showed homogeneous and uniform distribution of Nickel deposited on the surface of silicon with excellent adhesion properties for all pH value.

The Effect of Temperature on Nickel Deposited as an Underlayer Between Copper Filler and Silicon Wafer

Through silicon via (TSV) has garnered a lot of interest in the semiconductor industry due to its ability to provide the shortest interconnect path. The coefficient of thermal expansion (CTE) mismatch between the copper (Cu) interconnection filler and the silicon (Si) wafer result in reliability issues of the TSV system. This research proposed the introduction of an underlayer between the Cu filler and Si wafer in order to reduce the CTE mismatch in the TSV. The chosen underlayer is nickel (Ni) as it has a CTE value placed in between Cu and Si at 13 ppm/°C (Cu = 17 ppm/°C, Si = 2.8 ppm/°C). The Ni layer was deposited using the electroless deposition process at different temperature of plating bath (75 °C, 85 °C, and 95 °C) and deposition time (20, 40, and 60 minutes). The analysis of the microstructure of the Ni layer deposited on the Si wafer was characterized. The adhesion test was conducted using the ATM D3359 (Measuring Adhesion by Tape Test) Standard for coating adhesion test and the 4-Point Probe Test for the resistivity measurement. It was found that the optimum Ni plating temperature was at 85 °C based on its adhesion and high stability of plating bath. The resistivity test showed that the increased of Nickel underlayer thickness deposited between copper and Si wafer has slightly increased the resistivity.

Qualification of brazing procedure for furnace brazing of austenitic steel according to requirements of the ASME BPVC section IX

The article presents the procedure for qualifying brazing technology in a vacuum furnace on the example of stainless steel elements joined with copper filler material from the F-No group. 105, in accordance with the ASME Sec. IX, part QB (ASME Boiler and Pressure Vessel Code. Qualification Standard for Welding, Brazing and Fusing; Procedures; Welders; Brazers; and Welding, Brazing and Fusing Operators). The essential variables of the furnace brazing process are discussed in relation to the requirements of the protocol of qualified PQR (Procedure Qualification Record) and BPS (Brazing Procedure Specification) in accordance with the ASME Sec. IX. The requirements for joints by the calculation code ASME Sec. VIII div.1 (Rules of Construction of Pressure Vessels), related to the working temperature of the designed device have also been taken into account. The paper presents examples of brazed joints made and their properties (strength, fill level of the clearance) obtained on the basis of the carried out tests. Attention was paid to the technological aspects during the performance of brazed joints using vacuum furnaces.

Electrical Property Improvement of Copper Filler Conductive Adhesive with Low-Melting Point Metal Bridge

Electrical Property Improvement of Copper Filler Conductive Adhesive with Low-Melting Point Metal Bridge

The Joining Behavior of Titanium and Q235 Steel Joined by Cold Metal Transfer Joining Technology.

Cold metal transfer process is applied to join titanium and Q235 steel with copper filler metal. Scanning electron microscope (SEM), energy dispersive spectrometer (EDS) analysis, micro-hardness tests, and tensile strength test were performed to investigate the joining mechanism and strength of joints. The results show that the stacking order of two base metals affected the joining modes and strength. For top Q235 steel to bottom Ti-TA2 lapped joint, there was no distinct interface reaction layer between the steel base metal and the weld metal; dispersed TiFe2 intermetalics (IMCs) IMCs between the steel base metal and the Ti base metal greatly improved the strength of joint; the tensile force of the joint could reach up to 93% that of steel-steel joint using the same welding parameters. Additionally, the joints were fractured in dimple mode at the steel base metal. For top Ti-TA2 to bottom Q235 steel lapped joint, the increasing volume fraction of Ti-Cu IMCs at the Ti-Cu weld metal interface contributed to the strength of joint degradation. The joints under tensile loading are initiated at the Ti-Cu weld metal interface between the weld metal and Ti base metal, then propagated to weld metal, finally fractured with brittle mode.

Interfacial microstructure evolution and mechanical properties of TC4 alloy/304 stainless steel joints with different joining modes

TC4 alloy(Ti)/304 stainless steel (SS) plates were butt joined using MIG-TIG double-sided arc welding(DSAW) with copper filler metal. Different joining modes, i.e., brazing mode, welding-brazing mode (Ti welding-SS brazing, SS welding-Ti brazing) and fusion welding mode, were achieved by regulating the welding parameters. The interfacial microstructures and mechanical properties of the joints were investigated. The results show that the interfacial microstructures and mechanical properties are strongly affected by the joining mode.For the joints with brazing mode and Ti welding-SS brazing mode, a straight Intermetallic compound(IMC) layer of Fe-Cu-Si and Ti-Fe-Cu-Si phases was respectively formed at the SS side brazing interface, resulting in the fracture at lower stress; the Ti side brazing and fusion interfaces both mainly consisted of Ti-Cu IMC layer. The joints with SS welding-Ti brazing mode and fusion welding mode led to the curved melted zone containing two phases of Fe(s,s) and Cu(s,s) at the SS side fusion interface. The tensile resistance of the interface was significantly enhanced attributed to the curved morphology and the suppression of the brittle IMCs. The fractures occurred at the Ti side interface, and the tensile strength was determined by the thickness of the reaction layer consisted of the Ti-Cu and Ti-Cu-Fe IMCs. Therefore, the SS welding-Ti brazing joint with a thinner reaction layer shows the maximum tensile strength, which is up to 319 MPa.

Butt brazing of titanium alloys/stainless steel plates by MIG-TIG double-sided arc welding process with copper filler metal

Butt brazing of titanium alloys with stainless steel by MIG-TIG double-sided arc welding (DSAW) process with copper filler metal has been performed. The microstructures and mechanical properties of the joint were investigated. The results show that a butt brazing joint with sound double-sided appearance was achieved. With low heat input of brazing mode and rapid cooling rate of arc welding process, the joint is free of brittle Ti-Fe intermetallic compounds (IMCs). The phase compositions in the joint are TC4/Ti2Cu+TiCu/TiCu+Ti5Si3/Cu+(Ti5Si3+Cu+βTiCu4)/Fe5Si3+(Cu)+FeSi/Fe(s,s)/304ss orderly from Ti6Al4V to 304ss. The average tensile strength of the butt joint reaches 278MPa. Compared with the fusion welding joint, the tensile strength of the arc-brazing joint is significantly increased because of the elimination of Ti-Fe IMCs.

Selective laser sintering of copper filled polyamide 12: Characterization of powder properties and process behavior

Commercially available materials for selective laser sintering (SLS) include mainly semicrystalline polymers and only a few composites like polyamide 12 filled with glass beads or aluminum. Powder composites can be used for setting tailored properties. Exemplarily, mechanical properties as well as thermal or electrical conductivity can be improved. Thermally conductive SLS parts filled with copper particles have not been under investigation before. This study contains the characterization of polyamide 12 filled with copper acting as a metal filler with a high thermal conductivity. Two composites differing in the filler shapes are investigated concerning powder properties and the resulting processability. The thermal conductivity in dependence on the filler content and anisotropy is of major interest. Isotropic, spherically shaped copper fillers are compared with strongly anisotropic flakes leading to the result that a much lower content of anisotropic filler is needed to reach an increased thermal conductivity. However, the powder flowability and processability is also highly influenced by the filler shape and content. Fillers with a similar shape like the matrix powder lead to a better flowability allowing higher filler contents. POLYM. COMPOS., 40:1801–1809, 2019. © 2018 The Authors Polymer Composites published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers

Thermal and Electrical Conductivity of Unsaturated Polyester Resin Filled with Copper Filler Composites

Thermal and electrical conductivity of unsaturated polyester resin with copper filler composite material are investigated both theoretically and experimentally. In the experiments, polyester matrix is combined with dendrite-shape copper to determine the effects of both filler size and content on thermal and electrical conductivity, respectively. It is observed that the increase in the concentration causes the thermal and electrical conductivity of composite mixture to grow up. It has also been observed that the both thermal and electrical conductivity increase with increasing filler particle size.

Influence of polyphenyl ester and nanosized copper filler on the tribological properties of carbon fibre–reinforced ultra-high-molecular-weight polyethylene composites

Ultra-high-molecular-weight polyethylene (UHMWPE) reinforced with carbon fibre (CF) and filled with polyphenyl ester (POB) and nanosized copper (Cu) fillers was prepared by compression moulding. The tribological behaviours and the synergism of the incorporation of fibre and particulates were studied. The proportions of the reinforcement material ranged from 5 wt% to 25 wt%, the filler material of POB varied from 5 wt% to 25 wt% and the nanosized filler was from 4 wt% to 12 wt%. In the sample with CF only, the lowest wear rate was observed for the UHMWPE + 15% CF composite. The particulate filler further reduced the composite wear rate, and the lowest wear rate was found for the hybrid with CF, POB and nanosize Cu particles, that is, for the UHMWPE + 15% CF + 15% POB + 12% Cu composite. The particulate filler was added, and the coefficient of friction slightly increased. The transfer film formed on the metal counterface was studied using optical microscopy, and the topography of the transfer film was investigated using atomic force microscopy. Results showed that the transfer films were thin, compact and uniform on the metal counterfaces of the UHMWPE + 15% CF + 15% POB + 12% Cu composite. Worn surface morphologies of composites were studied using scanning electron microscopy. Results showed that the worn surface of the UHMWPE + 15% CF + 15% POB + 12% Cu composite was smoother and had better wear resistance than that of other composites.

Effects of Metal Fillers on Properties of Epoxy for Rapid Tooling Inserts

Metal filled epoxy has been recognised as an alternative material used in rapid tooling application such as core and cavity for injection moulding. The addition of fillers into the metal filled epoxy has proven to increase the epoxy’s mechanical performance such as wear, strength, improved machinability and thermal properties. Physical and thermal properties such as density, thermal diffusivity , thermal conductivity and compressive strength were analysed to evaluate the effects of inclusion of metal fillers such as copper and brass particles into the blended epoxy matrix. Brass and copper powders were added separately ranging from 10%, 20% and 30% of its weight into the aluminium filled epoxy mix ratio. Increased density, thermal diffusivity and thermal conductivity values were evident with a linear trend when both filler compositions were increased from 10% to 30%. Brass and copper density values of 2.22 g/cm 3 and 2.08 g/cm 3 respectively were recorded at the highest filler composition. Copper fillers with 30% composition in epoxy matrix exhibited the highest average value of thermal diffusivity of 1.12 mm 2 /s and thermal conductivity of 1.87 W/mK, while inclusion of brass showed no significant improvement on the properties. Compressive strength increased from 76.8 MPa to 93.2 MPa with 20% of brass fillers and 80.8 MPa with 10% of copper fillers composition. The addition of more metal fillers resulted in a decrease in compressive strength due to the presence of porosity. This study validated previous researchers that fillers enhance mechanical, thermal properties and density of aluminium filled epoxy.

Investigation of interfacial structure and mechanical properties of titanium clad steel sheets prepared by a brazing-rolling process

Three types of titanium clad steel sheets were fabricated by a hot-roll bonding process at different rolling reductions (40%, 55%, and 65%). The specimens with stacking sequences of TA1/steel/TA1, TA1/T2/steel/T2/TA1 and TA1/BAg-8/steel/BAg-8/TA1, corresponding to Ti/steel clad composites bonded without a filler, with a red copper filler, and with a BAg-8 filler, are referred to here as Ti-steel, Ti-T2-steel, and Ti-Ag-steel, respectively. The Ti-steel specimen was prepared by direct hot-roll bonding with its four sides welded by arc welding, while the Ti-T2-steel and Ti-Ag-steel specimens were prepared by a combined brazing and hot-roll bonding process, named as a brazing-rolling process. These three types of as-roll bonded specimens were subjected to heat treatments, under 65% rolling reduction. The bonding quality, interface structure evolution, and mechanical properties of the clad composites were systemically studied. The results showed that the reduction in the shear strength of Ti-T2-steel under 65% rolling reduction was due to the poor interface components. The presence of brittle intermetallic compounds (IMCs) and the rapid increase of α-β Ti at the interface of Ti-T2-steel with increasing temperature were regarded as the key factors influencing interfacial failure. The formation of the TiFe2 phase at 800°C for Ti-Ag-steel provided major sites for the nucleation and propagation of cracks during the tensile tests, leading to interfacial delamination. The experimental elongation values of these three types of clad composites were enhanced significantly at all heat-treatment temperatures compared with the calculated elongation values using the rule of mixture (ROM). In addition, the experimental values of yield strength (YS) decreased while those of the ultimate tensile strength (UTS) increased for Ti-Ag-steel, in contrast with the corresponding values by ROM, suggesting the favourable formability of the clad composite by lamination owing to low yield ratio.