Insert Metal Research Articles

Ultrasonic Welding Mild Steel Sheet to Al-Mg Alloy Sheet

Ultrasonic welding between SS400 mild steel sheet and aluminum alloy A5052 sheet containing magnesium was conducted. In this study, authors investigated the influence of ultrasonic welding condition on the mechanical properties and the interface microstructure of a joint, and examined the effect of an insert metal to improve the joint strength. The main results obtained in this study are as follows. It was possible to ultrasonically weld SS400 mild steel sheet and A5052 sheet. When the clamping force was varied keeping the welding time constant for 1s, the joint strength showed the maximum at the clamping force of 588N and it decreased with increasing the clamping force because the frictional action at the interface decreased with it. When the clamping force was kept constant at 588N and the welding time was varied, the joint strength reached the maximum at the welding time of 2.5s, followed by decreasing in the joint strength welded at 3s welding time due to the formation of Fe2Al5 intermetallic compound at the interface. Using insert metal of commercially pure aluminum successfully improved the joint strength and the strength of the joint welded at 3s welding time was about three times larger than that without the insert metal.

Effect of Weld Tip Geometry on Ultrasonic Welding between Steel and Aluminum Alloy

In this study, authors investigated the effect of horn tip geometry on the mechanical properties of a joint ultrasonically welded between a mild steel sheet and an aluminum alloy sheet. Two types of weld tips with the different contact face geometries were employed. One type of a tip has a cylindrical contact face without knurl. The other type of a tip has flat contact face with knurl. The main results obtained in this study are as follows. Authors successfully welded the mild steel sheet to the aluminum alloy sheet using both of the weld tips. However, the strength of the joint welded by the tip with cylindrical geometry was higher than that welded by the flat tip with knurl under the same welding condition, and the strength of the joint by the tip with cylindrical geometry was twice larger than that by the flat tip with knurl under the optimal welding condition. The strength of the joint increased with increasing the welding time and the clamping force, and showed the maximum under the reasonable welding condition. Excessively long welding time and large clamping force damaged the workpiece surface contacted the horn side tip, resulting in the decrease of the joint strength. It was possible to improve the joint strength using commercially pure aluminum foil with suitable thickness as insert metal.

431 ステンレス鋼ろう付圧接継手における鋭敏化の評価(溶接・接合のプロセスと評価(2,加工・検査のロボット・知能化,ものづくりにおける基礎研究と先端技術の融合)

It was investigated that effect of the thermal history during the braze-pressure-welding process for the austenitic stainless steel to its sensitization property. The SUS304 austenitic stainless steel pipes were joined using the braze-pressure-welding method with the induction heating. The cleaning metal, or insert metal, was the Fe-base alloy (Fe(Bal.)-20Cr-l0Ni-3Si- 2.5B-1Mo). For the cross section samples of the pipe wall with various distance from the joint interface, the degree of the sensitization was measured using the EPR method. The grain size of the samples was also measured to modify the degree of the sensitization. The value of the sensitization was high at the vicinity of the joint interface, but it dropped with the distance. It was shown that the severe sensitization did not occur by the BPW process.

レジスト薄膜インサート金属粉末射出成形によるマイクロ構造体の作製と粉末粒径の影響

The manufacturing method of resist film insert metal powder injection molding (MIM) namely Resist/μ-SpiMIM process has been proposed. The resist film made of PMMA polymer with numerous micro-holes was used as micro sacrificial plastic mold (SP-mold). A novel molding machine which could achieve to mold without pelletizing was also used to produce the green compacts with a high efficiency in experiment by using a small amount of feedstock. The feedstock prepared by pure copper powders with various particle sizes was injection-molded into the SP-mold and the sintered parts with micro-pillar structure were produced after debinding and sintering process. The effects of particle size on density, shape-transcription and surface roughness of those sintered parts were discussed. The decreasing of particle size results in a marked improvements of surface roughness, transcription and dimensional variation of sintered parts.

Ultrasonic welding between mild steel sheet and Al–Mg alloy sheet

Ultrasonic welding between SS400 mild steel sheet and aluminum alloy sheet containing magnesium (A5052) was conducted. In this study, authors investigated the influence of ultrasonic welding conditions on the mechanical properties and the interface microstructure of a joint, and the effect of insert metal was examined to improve the joint strength. The main results obtained in this study are as follows. It was possible to weld ultrasonically SS400 mild steel sheet to A5052 aluminum alloy sheet containing magnesium. The strength of the joints welded using various clamping forces and constant welding time of 1.0 s showed the maximum value at the clamping force of 588 N and decreased with the clamping force over 588 N because the excessively large clamping force reduced the frictional action at the interface. The strength of the joints welded using the constant clamping force of 588 N and various welding times showed the maximum value at the welding time of 2.5 s. However, the strength of the joint welded using the welding time of 3.0 s decreased due to the formation of Fe 2Al 5 intermetallic compound at the interface. Using the insert metal of commercially pure aluminum, the joint strength was successfully improved and the strength of the welded using 3.0 s welding time was about three times as large as that of the joint without the insert metal.

Multi-component microinjection moulding-trends and developments

With standard microinjection moulding becoming more and more established in practical manufacturing, special variants are attracting increasing attention. Especially, the approaches on multi-component microinjection moulding are worth mentioning: As handling and assembly are difficult procedures especially in microtechnology, methods to reduce mounting efforts are of high economic importance. By merging of shaping and mounting procedures in one step, economic progress as well as new material combinations can be obtained. An interesting approach for the fabrication of metal (or in principal, ceramic) microcomponents is the combination of insert injection moulding and metal deposition by electroforming. First, an electrically conductive base plate is produced by injection moulding of conductively filled polymers. In a second injection moulding step, microstructures consisting of insulating plastics are mounted on these plates. The quasi-infinite conductivity gradient allows controlled electroplating starting at the base plate only so that defect-free metal microcomponents can be achieved. As a further variant of microinjection moulding, the development of the so-called MicroPIM process facilitates a large-scale series fabrication technology for metal and ceramic microcomponents. Combined with multi-component technology, an interesting new approach for micromanufacturing is obtained, i.e. the realisation of magnetic/non-magnetic or conductive/non-conductive material combinations by two-component MicroPIM. But, also the combination of different mechanical properties like hard/tough pairings is possible.

軟鋼とマグネシウム合金の抵抗スポット溶接

Authors tried to weld a steel plate to Mg alloy plate using a resistance spot welding method. In welding of the dissimilar materials, the authors employed SUS304 insert metal and investigated the effect of the insert metal and the electrode tip geometry on the strength of the welds. The following results were obtained.When the steel plate was directly welded to Mg alloy plate without the insert metal, the temperature around the welded area and the strength of the weld increased with increasing welding current. The reason seems to be that the bonded area increases due to the increase in nugget diameter of Mg alloy and that the oxide film on the faying surface of the steel is easily reduced by the molten magnesium.The insert metal of SUS304 with optimal thickness significantly improved the strength of the weld, however, the excessively thick insert metal increased the amount of magnesium expulsion and resulted in decreasing the weld strength.The electrode tip with flat geometry attached a steel washer improved the strength of welds because the plunging depth of the electrode tip into the Mg alloy plate was decreased, resulting in the decrease of the molten magnesium expulsion.

LIGA犠牲樹脂型インサート金属粉末射出成形によるマイクロ構造体の製造

The manufacturing method of micro sacrificial plastic mold (SP-mold) insert metal injection molding (MIM) combined LIGA process, namely LIGA/μ-SPiMIM process has been proposed to solve specific problems involving the miniaturization of MIM. Two types of SP-molds with fine structures were used: 1) PMMA resist, 2) PMMA mold injected into Ni-electroform, which is a typical LIGA process. Stainless steel 316L feedstock was injection-molded into the SP-molds with multi-pillar structures. To reduce the defects in plastic injection molding such as weld-line and short filling, which were developed around micro pillar structures of molded parts, the molding conditions for producing the SP-molds were optimized. This study also focused on the effects of metal particle size and processing conditions on the shrinkage, transcription and surface roughness of sintered parts.

A case of insert fracture and metal shell penetration by the inner head after ceramic-on-ceramic THA

We report a case of insert fracture and metal shell penetration by the inner head after ceramic-on-ceramic THA. A 67-year-old female underwent ceramic-on-ceramic THA (Osteonics Secur-Fit HA, Ceramic-on ceramic Bearing System, Stryker) in another hospital. However, she noticed pain and crepitation and first visited our hospital due to aggravation of pain. Radiograph showed insert fracture and metal shell penetration by the inner head, and she was admitted for revision. During the operation, the intra-articular area showed marked metallosis. In the anterior area of the metal shell, there was a hole due to penetration by the inner head. The metal shell was removed and the acetabulum was reconstructed by filling with reinforcement granules, followed by implantation of a KT plate.

분말 혼합 공정으로 만들어진 은계 삽입금속의 특성

Ag계 분말 삽입금속을 볼 밀링법으로 제조하였다. 밀링공정의 변수들은 밀링시간을 제외하고는 일정하게 하였고 밀링 시간은 24, 48, 72시간들로 정하였다. 밀링에 의해 제조된 삽입금속들은 SEM관찰, DSC분석, 퍼짐성, 젖음성 시험을 통해 평가하였다. 삽입금속들의 브레이징부 특성은 상용금속에 비하여 우수하였다. 48시간 동안 밀링한 삽입금속이 퍼짐성과 젖음 특성이 가장 우수한 조건임을 나타냈다. 또한 브레이징부는 작은 양의 기공을 포함하고 있지만 안정적인 미세조직을 보였고 미세경도는 138VHN으로 나타났다. 【Powder type Ag system insert metals were manufactured by ball milling process. The variables of milling process were constant except the milling time. The milling times were selected for 24, 48 and 72 hours. The insert metals made by milling process were evaluated by performing scanning electron microscope, DSC(differential scanning calorimetry) analyses, spreading test and further in terms of wettability test. The selected insert metals that have the good characteristics compared to commercial insert metals were applied to make the brazed joints. The characterizations of those brazed joints were also conducted by microstructural observations. The results indicated that milling time of 48 hours for making powder type insert metals was the best condition showing the good spreadibility, low wetting angle. The brazed joints that applied the 48 hours milled insert metal were very sound condition indicating the stable microstructure in spite of containing small amount of porosity and the microhardness value of the joint was about 138VHN.】

은계(BAg) 삽입금속으로 접합된 초경합금 입자와 탄소강 브레이징부의 특성

초경합금입자와 탄소강사이의 브레이징 접합부 특성을 평가하였다 선택된 두 종류의 삽입금속은 기계적 합금 공정으로 만들어졌다. 한 가지는 Cu, Zn, Ag (MIM-1) 그리고 다른 한 가지는 Cu, Zn, Ag과 Cd(MIM-2)로 구성하였다. 삽입금속들의 화학조성은 AWS BAg-20계와 BAg-2a계의 성분과 유사하였다. 그리고 상용삽입금속들(CIM-1, CIM-2) 역시 비교 평가하였다. 삽입금속들의 특성은 젖음성 시험, 전단강도 시험, 그리고 미세조직 관찰로서 나타내었다. 젖음성 시험에서 MIM-1과 CIM-1 삽입금속의 젖음각이 MIM-2와 CIM-2보다 크게 나타났고, MIM-1의 젖음각이 CIM-1보다 더 큰 값을 나타났지만 모든 경우 젖음각이 <TEX>$25^{\circ}$</TEX>보다 작았다. 삽입금속, MIM-1이 가장 높은 전단강도를 나타냈고, 그 값은 <TEX>$2.29{\times}10^2MPa$</TEX>로 측정되었다. 이 값은 상용 삽입금속의 값과 같거나 높은 것으로 나타났다. 삽입금속의 미세조직은 Cu-rich 초정영역과 Ag-rich 공정영역으로 구성되었다. MIM-1계로 만들어진 초경합금과 탄소강의 접합부는 일부 접합부 계면에 기공을 포함하지만 초정을 기지로 하는 안정적인 미세조직을 나타냈다. This study was carried out to evaluate brazing characteristics of the braze joint between superhard alloy particles and carbon steel. Two types of insert metals that made by mechanical alloying process were selected for this study. One is composed of Cu, Zn and Ag(MIM-1) and the other one is composed of Cu, Zn, Ag and Cd.(MIM-2) The chemical compositions of these insert metals were similar to AWS BAg-20 and BAg-2a system. And the commercial insert metals(CIM-1, CIM-2) were also evaluated for the comparative study. The characterization of the insert metals were conducted by wettability tests, shear tensile test and microstructural analyses. The results indicated that wettability tests displayed that MIM-1 and CIM-1 insert metals had the larger wetting angle than MIM-2 and CIM-2 and the wetting angle of the MIM-1 showed higher value than that of CIM-1. However these values are less than <TEX>$25^{\circ}$</TEX> that is recommended for standard value for usual insert metals. The highest value of shear tensile tests was obtained from the brazed joint that made by MIN-1 and the value was <TEX>$2.29{\times}10^2MPa$</TEX>. This value is appeared to be higher or same as the commercial insert metals. The microstructures of the inserts metals were composed of Cu-rich proeutectic structure for matrix and Ag-rich eutectic structure. The braze joint between superhard alloy particles and carbon steel produced by the MIM-1(Ag-Cu-Zn) system showed sound joint showing stable microstructures. However there was also some porosities at the interface.

Solid State Bonding of Carbon Material to Copper with Nickel Insert

Carbon material/nickel/copper system was heated under a compressive stress of 13 MPa in a vacuum at 1073 K for different keeping times, and the bending strength of the joint, the microstructure, hardness and carbon concentration near the joining interface were examined. Thermal stress induced in the joint was estimated by a finite element method. In carbon material/copper system solid state bonding is difficult. However, good solid state bonding becomes feasible when nickel is used as an insert metal. Axisymmetric thermoelastic finite element analysis reveals that the maximum tensile thermal stress is induced on the surface of carbon material near the joining interface, and it decreases with increasing nickel thickness. The maximum residual tensile thermal stress in practical joints is less than the maximum tensile thermal stress calculated by finite element method because the thermal stress is released. [doi:10.2320/matertrans.H-MRA2008819]

Quality Improvement in Micro Sacrificial Plastic Mold Insert Metal Injection Molding

Quality Improvement in Micro Sacrificial Plastic Mold Insert Metal Injection Molding

Effect of brazing conditions on the microstructure and mechanical properties of duplex stainless steels to Cr−Cu alloy with Cu−base insert metal

The brazing of a copper-chromium alloy and DSS (Duplex stainless steel) was conducted under various conditions to investigate the bonding phenomena, microstructures and mechanical properties. The reactions of liquid insert metal with dissimilar base metals, a Cu−Cr alloy and DSS produced various phases in the bond zone. The chemical composition and the volume fraction of the phases varied as a function of the brazing conditions. The Cu phase for the DSS and piece of stainless steel separated from the DSS was produced from the reaction of the insert metal and the SSS. In addition, the Cr−Mn phase, Mn−Fe phase and Fe−Cr phase were formed by the reaction between the insert metal and each base metal. As the brazing temperature and time increased; the amounts of the Cu phase and the number of stainless steel pieces increased. In addition, the Mn−Fe phase varied compared to the Fe−Cr phase after brazing at 1273 K at 0 min. The Cr−Mn phase initially increased but eventually decreased after holding times of 15 min at 1273 K and 7 min at 1303 K.

일방향 초내열합금 GTD-111DS에서 삽입금속 분말에 따른 천이액상확산접합부의 접합강도 특성

The Ni-base superalloy GTD111 DS is used in the first stage blade of high power land-based gas turbines. Advanced repair technologies of the blade have been introduced to the gas turbine industry over recent years. The effect of the filler metal powder on Transient Liquid Phase bonding phenomenon and tensile mechanical properties was investigated on the GTD111 DS superalloy. At the filler metal powder N series, the base metal powders fully melted at the initial time and a large amount of the base metal near the bonded interlayer was dissolved by liquid inter metal. Liquid filler metal powder was eliminated by isothermal solidification which was controlled by the diffusion of B into the base metal. The solids in the bonded interlayer grew from the base metal near the bonded interlayer inward the insert metal during the isothermal solidification. The bond strength of N series filler metal powder was over 1000 MPa. and <TEX>${\gamma}'$</TEX> phase size of N series TLP bonded region was similar with base metal by influence of Ti, Al elements. At the insert metal powder M series, the Si element fluidity of the filler metal was good but microstructure irregularity on bonded region because of excessive Si element. Nuclear of solids formed not only from the base metal near the bonded interlayer but also from the remained filler metal powder in the bonded interlayer. When the isothermal solidification was finished, the content of the elements in the boned interlayer was approximately equal to that of the base metal. But boride and silicide formed in the base metal near the bonded interlayer. And these boride decreased with the increasing of holding time. The bond strength of M series filler metal powder was about 400 MPa.

Joining of superalloy Inconel 600 by diffusion induced isothermal solidification of a liquated insert metal

The effect of process variables on the microstructure of transient liquid phase bonded IN 600 using a commercial filler alloy was studied. Microstructural examination of bonded specimens showed that isothermal solidification of the liquated insert occurred during holding at the joining temperatures. In cases where the holding time was insufficient for complete isothermal solidification, the residual liquid transformed on cooling into a centerline eutectic product. The width of the eutectic decreased with increased holding time and an increase in initial gap width resulted in thicker eutectic width in specimens bonded at the same temperature and for equivalent holding times. In addition to the centerline eutectic microconstituent, precipitation of boron-rich particles was observed within the base metal region adjacent to the substrate–joint interface. Formation of these particles appeared to have influenced the rate of solidification of the liquated interlayer during bonding. In contrast to the conventional expectation of an increase in the rate of isothermal solidification with an increase in temperature, a decrease in the rate was observed with an increase in temperatures above 1160 °C. This could be related to a decrease in solubility of boron in nickel above the Ni–B eutectic temperature.

유사 조성의 모재분말과 Ni기 삽입금속 혼합분말을 사용한 천이액상확산 접합 시 모재의 용해현상

The dissolution phenomenon of the solid phase powder and base metal by liquid phase insert metal during Transient Liquid Phase bonding using the mixed powder composed of the modified GTD111(base metal) powder and the GNi3 (Ni-l4Cr-9.5Co-3.5Al-2.5B) powder was investigated. In case of the mixed powder contains modified GTD111 powder 50wt%, all of the powder was melted by liquid phase at 1423K. At the temperature between solidus and liquidus of GNi3, liquid phase penetrated into the boundary of the modified GTD111 powder and solid particle separated from powder was melted easily because area of reaction was increased. With increasing mixing ratio of the modified GTD111, it needed the higher temperature to melt all of the modified GTD111 powder. During Transient Liquid Phase bonding using the mixed powder composed of the modified GTD111 50wt% and GNi3 50wt% as insert metal, width of the bonded interlayer was increased with increasing bonding temperature by reaction of the base metal and liquid phase in insert metal. Dissolution of the base metal and modified powder by liquid phase progressed all together and after all of the powder was melted nearly, the dissolution of the base metal occurred quickly.

Effect of bonding temperatures on the transient liquid phase bonding of a directionally solidified Ni-based superalloy, GTD-111

The bonding phenomenon and the mechanism involved in the transient liquid phase bonding (TLP Bonding) of directionally solidified Ni-based superalloy GTD-111 was investigated. At a bonding temperature of 1403 K, the liquid insert metal was eliminated by isothermal solidification, which was controlled by the diffusion of B and Si into the base metal. The solids in the bonded interlayer simultaneously grew epitaxially from the mating base metal inward from the insert metal. The number of grain boundaries formed at the bonded interlayer corresponded with those of the base metal. Liquefaction at the grain boundary and dendrite boundary occurred at a temperature of 1433 K. At a bonding temperature of 1453 K which is higher than the liquefaction temperature of the grain boundary, liquids of the insert metal were connected with liquated grain boundaries; this connection extended as far as the grain boundary, which was approximately 1.5 mm from the interface. The composition of this liquid was a mixture of the insert metal and phase that existed at the grain boundary. At extended holding times, liquid phases gradually decreased, and liquids with a continuous band shape develop into distinct islands. However, the liquid phases did not disappear after a holding period of 7.2 ks at 1453K. The extended isothermal solidification process at the bonding temperature, which is higher than the liquefaction temperature for the grain boundary, was controlled by the diffusion of Ti. This resulted in its preferential liquefaction compared to B or Si in the insert metal.

軟鋼板とAl-Mg合金板の超音波接合

Abstract Ultrasonic welding between SS400 mild steel sheet and aluminum alloy sheet containing magnesium (A5052) was conducted. In this study, authors investigated the influence of ultrasonic welding conditions on the mechanical properties and the interface microstructure of a joint, and the effect of insert metal was examined to improve the joint strength. The main results obtained in this study are as follows. It was possible to weld ultrasonically SS400 mild steel sheet to A5052 aluminum alloy sheet containing magnesium. The strength of the joints welded using various clamping forces and constant welding time of 1.0 s showed the maximum value at the clamping force of 588 N and decreased with the clamping force over 588 N because the excessively large clamping force reduced the frictional action at the interface. The strength of the joints welded using the constant clamping force of 588 N and various welding times showed the maximum value at the welding time of 2.5 s. However, the strength of the joint welded using the welding time of 3.0 s decreased due to the formation of Fe 2 Al 5 intermetallic compound at the interface. Using the insert metal of commercially pure aluminum, the joint strength was successfully improved and the strength of the welded using 3.0 s welding time was about three times as large as that of the joint without the insert metal.

Innovations in Micro Metal Injection Molding Process by Lost Form Technology

The production method of micro sacrificial plastic mold insert metal injection molding, namely μ-SPiMIM process has been proposed to solve specific problems involving the miniaturization of MIM. The sacrificial plastic mold (SP-mold) with fine structures was prepared by injection-molding polymethylmethacrylate (PMMA) into Ni-electroform, which is a typical LIGA (Lithographie-Galvanoformung-Abformung) process. Stainless steel 316L feedstock was injectionmolded into the SP-mold which had micro structures with multi-pillars. The green compact was demolded as one component with the SP-mold, which was decomposed along with binder constituent of feedstock in debinding process. This study focused on the effects of metal particle size and processing conditions on the shrinkage, transcription and surface roughness of sintered parts, which were evaluated by SEM (Scanning Electron Microscope) observation.