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"ABSTRAKResistance Spot Welding (RSW) merupakan proses menyambung logam dengan menggunakan arus dan sifat physical properties logam. Sehingga diperlukan gabungan analisis Electrical-Themal-Mechanical untuk mempelajari hasil las yang memiliki qualitas yang baik. Untuk memprediksi besar nugget las, simulasi RSW model 2D axissymetric dikembangkan dengan menggunakan sifat dari Electrical Contact Resistace (ECR). Tujuan penelitian ini adalah mempelajari pengaruh initial value ECR dan ketebalan ECR terhadap formasi nugget las. Variasi parameter pada penelitian ini adalah arus, ketebalan permukaan kontak, dan initial value ECR. Pada penelitian ini menunjukan bahwa untuk mendapatkan hasil nugget las yang berbentuk elips dan dapat menyambung antar plat metal yaitu dengan menentukan initial value ECR dan ketebalan ECR pada permukaan kontak antar plat metal (Al-Al) lebih besar dibandingkan dengan permukaan plat metal dan elektroda (Al-Cu). Setelah melakukan perbandingan dengan hasil experimen, simulasi RSW dengan menggunakan arus 8 kA dan initial value ECR dari permukaan kontak antar plat metal (Al-Al) dan plat - elektroda (Al-Cu) yaitu 230-28.75 µΩ memiliki selisih rata-rata 4.8 %. Dengan gaya elektroda 500 N dan expansi thermal yang terjadi pada specimen, stress maksimal yang dihasilkan sebesar 4 GPa.

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ABSTRACTResistance Spot Welding (RSW) is a process of joining metals using current and the physical properties of metals. A coupled of Electrical-Thermal-Mechanical analysis is needed to study welding results that have good quality. To predict the size of the welding nugget, the RSW simulation of the 2D axisymmetric model was developed using the properties of the Electrical Contact Resistance (ECR). The purpose of this study was to investigate the effect of the initial value ECR and ECR thickness on the formation of weld nuggets. The parameter variations in this study were current, contact surface thickness, and initial value of ECR. The results of this study showed that in order to achieve weld nuggets that could join metal sheets with ellipse formation weld nugget, the simulation used initial value ECR and ECR thickness of between metal sheets (Al-Al) greater than the contact surface of metal sheet and electrode (Al-Al). By making comparisons with experimental results, welding simulations by using 8 kA current and the initial ECR value of the contact surface between metal sheets (Al-Al) and the metal sheet-electrode (Al-Cu) with 230-28.75 µΩ, had an average error of 4.8%. By using electrode force 500 N and occurring thermal expansion, the maximum generated stress was 4 GPa."

"Resistance spot welding (RSW) merupakan metode pengelasan yang sudah banyak digunakan dalam dunia industri terutama industri otomotif. RSW menggabungkan dua pelat metal menggunakan panas yang berasal dari arus elektrik. Untuk mengurangi biaya yang digunakan untuk melakukan eksperimen secara langsung, simulasi RSW mulai dikembangkan. Simulasi RSW membutuhkan Initial Value dari electric contact resistance yang terdapat pada RSW. Penelitian ini bertujuan untuk mencari Initial Value tersebut agar simulasi dapat dilaksanakan. Initial value yang ditemukan akan digunakan untuk simulasi selanjutnya. Penelitian dilakukan menggunakan eksperimen dan juga simulasi untuk dapat membandingkan hasil dari dua metode tersebut. Pada eksperimen RSW, parameter yang divariasikan adalah cycle time. Cycle Time divariasikan sebanyak 1, 2, 3, 4, 5, 6, 7, 8, 9, dan 10 . Pada simulasi RSW, parameter yang divariasikan adalah waktu pengelasan yaitu selama 20ms, 40ms, 60ms, 80ms, 100ms, 120ms, 140ms, 160ms, 180ms, dan 200ms. Hasil las berupa ukuran nugget dari dua metode tersebut akan dibandingkan. Perbandingan hasil menunjukkan bahwa simulasi dengan initial value 200 memiliki ukuran nugget yang paling mendekati rata-rata ukuran nugget eksperimen.

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Resistance spot welding (RSW) is a commonly used welding method in industry, especially in automotive industry. RSW joins two metal plates using heat generated from electric current. To reduce the experiment cost, RSW simulation developed. RSW simulation needs Initial Value from electric contact resistance that consists on RSW. This research is conducted to find the initial value needed for RSW simulation. The initial value will be used for the next simulation Both experiments and simulations will be conducted in this research to compare the results. In RSW experiment, the variated parameter is cycle Time. The cycle time is variated as 1, 2, 3, 4, 5, 6, 7, 8, 9, dan 10. In RSW simulation, the variated parameter is welding Time as 20ms, 40ms, 60ms, 80ms, 100ms, 120ms, 140ms, 160ms, 180ms, and 200ms. The welding result of the nugget size of the two methods above will be compared. Comparison results show that simulation with initial value of 200 has the closest nugget diameter result with experiment."

"Resistance spot welding (RSW) is widely used in industries such as the aerospace, automotive, and electrical application industries. RSW is very useful for joining aluminum and its welding parameters lead to good quality joints. This research studied the influence of the welding parameters, such as welding current, welding time, and the electrode force, of micro resistance spot welding (MRSW) on the mechanical properties and fracture of a nugget of aluminum alloy (AA) 1100. AA 1100 plate with a thickness of 0.4 mm was used in this experiment. An alternating current (AC) RSW machine and electrode were used in this study. The welding parameters used in this study are welding current, welding time, and electrode force. Holding time is assumed to be constant. The welding time values of 6 CT, 8 CT, and 10 CT were combined with a welding current of 8 kV, and electrode forces of 32 kg, 42 kg, and 52 kg. The results showed that by increasing the electrode force, the load rate decreases, and the elongation distance tends to decrease, except for the electrode force of 52 Kg. The effect of the electrode force on the diameter and thickness of the weld nugget was not significant."

"ABSTRAKResistance spot welding (RSW) merupakan proses pengelasan yang sering digunakan untuk menyambung pelat logam umumnya pada industri otomotif dan penerbangan. Proses pengelasan RSW (Resistance Spot Welding) melibatkan fenomena kelistrikan, termal-mekanik, metalurgi, dan permukaan yang kompleks. Tidak seperti proses pengelasan lainnya, peristiwa terbentuknya sambungan las pada proses RSW terjadi sangat cepat (dalam mili-detik) dan mengambil tempat diantara benda kerja yang tumpang tindih satu sama lain. Simulasi pengelasan memungkinkan pemeriksaan visual terhadap sambungan las tanpa harus melakukan eksperimen yang mahal. Ukuran nugget las merupakan parameter yang paling penting dalam menentukan perilaku mekanik dari sambungan las RSW karena kualitas dan kekuatan sambungan las RSW secara dominan ditentukan oleh bentuk dan ukuran dari nugget las. Simulasi pemodelan proses pengelasan RSW dilakukan menggunakan modul ANSYS Parametric Design Language (APDL) berbasis metode elemen hingga (finite element method) yang tersedia, dalam ANSYS. Interaksi elektrikal dan termal dikembangkan untuk mempelajari pertumbuhan nugget pada pengelasan pelat aluminium A1100 dengan ketebalan masing-masing 0.4 mm. Dengan menggunakan pendekatan model simulasi ini, ukuran diameter nugget dapat diprediksi dengan baik melalui distribusi temperatur yang terbentuk selama proses pengelasan berlangsung. Pengelasan dilakukan dengan membuat variasi pada pemberian kuat arus (1kA dan 2kA) dan waktu pengelasan untuk masing-masing kuat arus yaitu 0.5, 1.0, dan 1.5 CT (cycle time). Diamater nugget untuk masing-masing parameter pengelasan yang didapat melalui simulasi pemodelan adalah, 4.276 mm, 4.372 mm, 4.668 mm, 5.616 mm, dan 5.896 mm. Pada spesimen dengan kuat arus 2 kA dan waktu pengelasan 1.5 CT, weld expulsion terjadi dan ditandai dengan menurunnya kekuatan tarik-geser dari spesimen tersebut dalam eksperimen.

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ABSTRAKResistance spot welding (RSW), generally which is one of the most often used to joint metal plate in the automotive and aviation industries. RSW welding process involves electrical, thermal-mechanical, metallurgy, and complex surface phenomenon. Unlike the other welding processes, weld joint formation in RSW process occurs very quick (in milli-seconds) and took place between the workpieces overlap each other. Welding simulation allows visual examination of the weld joint without having to perform an expensive experiment. Weld nugget size is the most important parameter in determining the mechanical behavior of welded joints in RSW process. The quality and strength of the weld joint in RSW process is predominantly determined by the shape and size of the weld nugget. Simulation modeling of RSW process performed using ANSYS Parametric Design Language (APDL) module based on the finite element method (FEM), embedded in ANSYS Workbench. Electrical and transient-thermal interaction was developed to study the weld nugget growth on resistance spot welding of aluminum A1100 metal plate with a thickness of 0.4 mm respectively. Weld nugget diameter can be well predicted by using this simulation model from the temperature distribution during the welding process. Welding is performed by varying the weld current (1 kA and 2 kA) and the welding time for each electric current which are start from 0.5, 1.0, and 1.5 cycle time. Nugget diameter for each of the welding parameters from the simulation modelling were 4,276 mm, 4,372 mm, 4,668 mm, 5,616 mm and 5,896 mm. Weld expulsion occurred for the specimen with welding current 2 kA and welding time 1.5 cycle time, characterized by the decreasing of the tensile-shear strength of the specimen."

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Resistance Spot Welding (RSW) adalah salah satu metode pengelasan yang meleburkan metal itu sendiri menggunakan arus listrik serta tekanan pneumatik. RSW sangat sering dijumpai di berbagai industri terutama industri otomotif dan industri dirgantara dimana diperlukan kecepatan untuk las titik serta temperatur yang terpusat. Elektroda dari tembaga biasanya adalah pilihan utama sebagai sumber penyalur arus listrik dan penekan. Bentuk dari elektroda itu sendiri berpengaruh atas ukuran nugget yang tercipta. Investigasi kali ini mencari dampak perubahan sudut elektroda terhadap besar nugget dengan memvariasikan bentuk elektroda dengan sudut kemiringan 30°, 45â?°, 60° terhadap benda kerja, serta bentuk Lab DTM. Nilai dari initial value contact resitance adalah 230 dengan menggunakan simulasi dari perangkat lunak ANSYS. Ditemukan hubungan bahwa semakin besar sudut elektroda terhadap benda kerja (semakin lancip elektroda) maka semakin besar juga diameter nugget yang tercipta. Hal ini dikarenakan ukuran elektroda yang mengecil sehingga current density dapat menjadi lebih terpusat. Hasil ini secara konsisten ditunjukan dengan berbagai variasi initial value. Didapati juga bahwa semakin besar initial value contact resistance, maka semakin besar juga diameter nugget.

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Resistance spot welding (RSW) is one of a few method of welding which melt its own metal using electric current and pneumatic pressure. RSW often found in various industry especially in otomotif industry and aeroplane industry where speed and temperatur distribution is really needed. Electrode made from copper usually is the main option for source of electric conductor and pressure. Shape of electrode itself affect the nugget size of the weld. This investigation will found the effect of changing the angle of attack of electrode for the weld nugget size with varying the angle from 30â?°, 45°, 60â?°, and DTM lab electrode. Value from initial value contact resistance will also be 230 using simulation with ANSYS APDL software. It was found that the bigger the angle (more pointed) electrode will produce a bigger weld nugget diameter. This is because of the electrode size getting smaller therefore creating a more focused current density resulting in bigger nugget weld. This result is consistent eventhough the initial value was changed. It was also found that the higher the inital value contact resistance, the nugget diameter would also got bigger.

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"Proses penyambungan logam dengan proses pengelasan merupakan proses penyambungan permanen yang masih sangat diperlukan dan terus dikembangkan pada proses manufaktur. Dengan memanfaatkan kelebihan sifat mekanik yang dimiliki masing-masing logam menjadikan latar belakang pengembangan pengelasan logam berbeda tipe dan jenis dissimilar welding , Resistance spot welding RSW salah satu teknologi pengelasan yang bisa dipakai untuk mengelas logam berbeda. Konsep efesiensi energi menjadi salah satu faktor yang dipertimbangkan dalam membuat konstruksi dengan konsep dimensi besar, mempunyai kekuatan yang dibutuhkan akan tetapi lebih ringan. Dengan demikian diperlukan pengembangan konstruksi ringan, konstruksi ringan sarang lebah honeycomb dari logam yang tipis dibuat dengan teknologi mikro RSW. Plat alumunium tebal 0,4 mm dapat disambung dengan sempurna menggunakan proses mikro RSW, parameter pengelasan yang paling optimal yaitu arus pengelasaan diatas 5 kV, waktu pengelasan 6 CT keatas, dan gaya elektrode lebih dari 343 N. Mikro RSW mampu menyambung plat baja tahan karat SS 301 ketebalan 0,2 mm dengan plat aluminium AA 1100 tebal 0,4 mm, akan tetapi sifat lebih rapuh. Mikro RSW mampu menyambung plat baja 0,2 mm, plat baja lapis seng 0,2 mm, dan plat alumunium 0,4 mm. Mikro RSW bisa dipergunakan untuk membuat konstruksi ringan dari plat-plat tipis, baja tebal 0,2 mm, baja lapis seng tebal 0,2 mm, dan aluminium tebal 0,4 mm. Konstruksi ini mampu menahan beban uji tarik lebih dari 5.000 N tanpa merusak sambungan lasan, konstruksi juga mampu menahan beban tekan mendekati 10.000 N, dengan 7 sambungan lasan robek, 9 sambungan retak.

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Metal joining process with welding technology is a permanent join which is still needed and is still developed in manufacturing industries. Advantage of mechanical properties from each metal can be joined together to get a great joint. RSW is one of some weld technologies used to weld dissimilar metals. An efficiency energy concept in a product design is a design concept to get a lightening product so a lightweight construction one of solution to reduce energy consume. A honeycomb construction in this study is a lightweight construction developed form stainless steel 0.2 mm of thin, galvanized zinc 0.2 mm, and aluminum 0.4 mm. Welding parameter optimized with welding current more than 5 kV, welding time more than 6 CT, and electrode force more than 343 N. Micro RSW could join SS 301 thin 0.2 mm with AA 1100 0.4 mm, however brittle weld nugget. Micro RSW can be used to join aluminum, zinc galvanized steel, and stainless steel in a honeycomb construction. Honeycomb has mechanical performance when withstand tensile load more than 5.000 N, weld nugget in the honeycomb was not failure moreover based metal or AA 1100 was tear. Honeycomb was joined by Micro RSW could hold compression load more 10.000 N, 7 tear and 9 crack of weld nugget."

"Sebuah mesin las resistansi untuk plat tipis baja dan aluminum telah didesain dan dibangun. Mesin tersebut diperuntukan untuk pengelasan plat pada struktur sandwich dimana mesin sebelumnya tidak dapat mengelas struktur tersebut. Mesin melewati dua jenis pengujian. Pengujian fungsional untuk menguji integrase sistem mesin dan pengujian performa untuk menguji kemampuan mesin mengelas spesimen plat tipis. Pengujian performa dilaksanakan pada pengelasan plat SS301 ketebalan 0.1 mm. Pengujian tarik kemudian dilaksanakan untuk mengukur kekuatan tarik spesimen. Hasilnya menunjukkan bahwa semakin tinggi gaya elektroda, semakin tinggi kekuatan tarik maksimumnya, yaitu 46,7 MPa pada pembebanan 50 kg. Spesimen lainnya menghasilkan kekuatan tarik maksimum 38,2 MPa dan 35,6 MPa pada pembebanan 30 kg dan 40 kg berturut-turut.

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A spot resistance welding machine for steel and aluminum thin plate was designed and built. It was intended to weld thin plate in a sandwich structure, which the previous existed machine was not able to weld. The machine was subjected to two types of testing. Functionality test to test the system integration of the machine and performance test to test the ability of machine to weld thin plate specimen. Performance test which was conducted was welding of SS301 plate with 0.1 mm thickness. Tensile test then conducted to measure the tensile strength of specimens. The result was specimen with higher electrode loading produce higher ultimate tensile strength, which is 46.7 MPa under 50 kg of loading. Other specimens produced 38.2 MPa and 35.6 MPa of ultimate tensile strength under 30 kg and 40 kg of loading respectively."

"Micro Resistance Spot Welding (MRSW) merupakan metode pengelasan yang banyak digunakan di industri manufaktur dikarenakan prosesnya yang cepat, efisien secara ekonomi, dapat diotomatisasi, dan dapat digunakan untuk pelat dengan ketebalan rendah. Pelat paduan aluminium dan brass, yaitu AA 1100 dan CuZn30 dengan ketebalan rendah merupakan bahan yang dewasa ini banyak digunakan dalam industri manufaktur dikarenakan sifatnya yang ringan dengan kekuatan mekanis yang baik. Belum terdapat penelitian yang membahas mengenai parameter optimum dari mRSW untuk pengelasan AA 1100 dan CuZn30. Dalam penelitian ini, dilakukan pengelasan terhadap pelat AA 1100 dan CuZn30 dengan dimensi 19 mm x 76 mm x 0,4 mm menggunakan instrumen pengelasan micro resistance spot welding (MRSW) otomatis dengan variabel cycle time pengelasan secara berturut-turut sebesar 3, 4, 5, 6, 7, 8, 9, 10 siklus. Karakterisasi hasil las dilakukan lewat analisis pengujian tarik. Pengujian tarik menunjukkan bahwa terjadi peningkatan nilai shear stress pada siklus/cycle time yang lebih besar.

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Micro Resistance Spot Welding (MRSW) is a welding method that is widely used in the manufacturing industry due to its fast, economically efficient, automable process and can be used for low thickness plates. Aluminum and brass alloy plates, namely AA 1100 and CuZn30 with low thickness are materials that are currently widely used in the manufacturing industry due to their lightweight nature with good mechanical strength. There are no studies that discuss the optimum parameters of micro resistance spot welding (MRSW) for welding AA 1100 and CuZn30. In this study, welding was carried out on the AA 1100 and CuZn30 plates with dimensions of 19 mm x 76 mm x 0.4 mm using an automatic mRSW welding instrument with a variable welding cycle time respectively 3, 4, 5, 6, 7, 8, , 9, 10 cycles. The characterization of welds was carried out through tensile testing. The tensile test shows that there is an increase in the value of shear stress at a greater cycle / cycle time."

"All metals have unique advantages and disadvantages in terms of their mechanical properties. Advantages such as flexibility are needed for construction and for the manufacture of sophisticated products. Some industries have improved the mechanical properties of metals by welding dissimilar ones together, such as aluminum alloy (AA) to stainless steel (SS) to reduce vehicle weights in order to improve fuel consumption. However, little research has been conducted on using micro resistance spot welding (mRSW) to join SS and Al by inserting a zinc (Zn) sheet between them as an interlayer. In this study, the mechanical properties of the weldment are tested using a shear test and Vickers micro hardness test. The results are compared using welding times of 6, 8 and 10 cycle times (CTs) and welding currents of 5 and 8 kA during the mRSW process. It is found that the SS, Zn and AA sheets could be joined with mRSW using an 8 kAA welding current and a 6 CT welding time. The micro hardness in the AA-Zn dissimilar joint increased relative to SS-Zn. Using a Zn sheet also improved displacement in the tensile shear test; however, it also increased the hardness of the diffusion zone."

"[ABSTRAKMaterial Bake Hardening merupakan material yang memiliki sifat mudah dideformasi sebelum diberi perlakuan panas dan sulit dideformasi setelah diberi perlakuan panas. Material ini merupakan material baru yang digunakan pada industri otomotif untuk digunakan pada kerangka mobil dan badan mobil. Material ini akan disambungkan menggunakan mesin Resistance Spot Welding. Resistance Spot Welding merupakan salah satu jenis pengelasan yang banyak digunakan di industri otomotif. Penelitian ini bertujuan untuk mengetahui pengaruh dari parameter kuat arus dari mesin resistance spot welding pada material bake hardening. Penyambungan material bake hardening ini dilakukan dengan menggunakan mesin resistance spot welding dengan pemberian kuat arus 8kA, 9kA, 10kA, 11kA dan 12kA. Pengujian yang dilakukan antara lain pengujian kekerasan, geser, pengamatan SEM, dan metalografi. Hasil penelitian menunjukkan bahwa kekuatan optimum yaitu 5,68kN dan kekerasan optimum yaitu 237,34 VHN didapat pada sampel yang diberi kuat arus sebesar 11kA. Pemberian kuat arus diatas 11kA akan menyebabkan penurunan pada kekuatan dan kekerasan. Pola penjejakan kekerasan menunjukkan bahwa daerah nugget memiliki kekerasan yang lebih tinggi dibandingkan base metal. Struktur mikro juga menunjukkan bahwa semakin ke daerah nugget, butir semakin membesar dan fasa bainite bertambah banyak.

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ABSTRACT

Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase.;Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase., Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase.]"