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"Material cerdas paduan ingat bentuk merupakan material yang memiliki kemampuan kembali ke bentuk semula setelah deformasi dengan perlakuan panas. Paduan ingat bentuk Cu-Zn-Al adalah salah satu paduan ingat bentuk dengan harga yang lebih murah dan mudah difabrikasi dibanding paduan ingat bentuk yang umum digunakan sepeti Ni-Ti. Pada Cu-Zn-Al sebagai paduan ingat bentuk memiliki kelemahan seperti stabilisa fasa martensit yang dapat dihindari dengan perlakuan panas dan metode pencelupan. Pada penelitian ini dipelajari pengaruh metode pencelupan terhadap sifat ingat bentuk pada paduan Cu-19,55Zn-7,04Al wt.% yang difabrikasi dengan proses pengecoran gravitasi. Hasil pengecoran gravitasi selanjutnya dihomogenisasi pada temperatur 850 oC selama 2 jam lalu didinginkan pada temperatur ruang. Setelah itu, paduan diberi perlakuan panas betatizing pada temperatur 850 oC selama 30 menit diikuti tiga metode pencelupan berbeda yaitu pencelupan langsung (direct quenching / DQ) ke dalam media air ditambah es kering, pencelupan naik (up quenching / UQ) ke dalam media air ditambah es kering selama 30 menit lalu dicelupkan lagi ke air mendidih 100 ℃ selama 30 menit, dan terakhir pencelupan bertahap (step quenching / SQ) dimana sampel dicelupkan pada air temperatur 100 ℃ selama 30 menit lalu diikuti pencelupan ke air ditambah es kering selama 30 menit. Karakterisasi paduan dilakukan menggunakan OES untuk uji komposisi, mikroskop optik dan SEM-EDS untuk mengamati struktur mikro, XRD untuk mengetahui struktur kristal, DSC untuk menganalisis transformasi fasa, Microvickers untuk pengujian keras dan uji pemuilahan regangan ingat bentuk menggunakan metode bending. Paduan as-cast dan as-homgenized memiliki struktur mikro yang didominasi oleh fasa β sebagai matriks dan fasa kedua seperti α yang berbentuk lath dan γ yang berbentuk seperti presipitat hitamdengan rasio fraksi fasa β:(α+ γ) sebesar 92:8. Untuk sampel hasil perlakuan panas, struktur mikro pencelupan DQ terdiri atas fasa martensit β’ yang berbentuk needle-like dan twin V. Struktur mikro pencelupan UQ memiliki struktur mikro martensit β’ berbentuk needle-like dan twin V dengan sedikit fasa kedua seperti fasa α dan γ. Struktur mikro pencelupan SQ memiliki martensit β’ berbentuk needle-like dan twin V dan fasa β. Kekerasan paduan untuk pencelupan langsung sebesar 155,61 HVN, pencelupan naik sebesar 179,76 HVN dan pencelupan bertahap sebesar 93,74 HVN. Pemulihan regangan untuk pencelupan langsung sebesar 72,05%, pencelupan naik sebesar 74,15% dan pencelupan bertahap sebesar 81,95%.

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The smart material shape memory alloy is a material that could revert to its starting form after deformation with heat treatment. Shape memory alloy Cu-Zn-Al is a cheaper and more easily fabricated shape memory alloy than the commonly used ones like Ni-Ti. The Cu-Zn-Al alloy as a shape memory alloy has a weakness in the form of phase stability, which could be avoided by heat treatment and quenching methods. This research studies the effect of the quenching method on the shape-memory properties in the Cu-19.55Zn-7.04Al alloy fabricated via gravity casting. The result of gravity casting was then homogenized at 850°C for 2 hours then cooled down at room temperature. Afterwards, the alloy was heat treated via betatization at 850°C for 30 minutes, followed by three different quenching methods of direct quenching (DQ) into a water medium with dry ice, up quenching (UQ) into a water medium with dry ice for 30 minutes before being quenched again into 100°C boiling water for 30 minutes, and step quenching (SQ) where the sample was quenched into 100°C water for 30 minutes then quenched into a water medium with dry ice for 30 minutes. Characterization of the alloy was conducted with OES to observe the composition, optical microscope and SEM-EDS to observe the microstructure, XRD to know the crystal structure, DSC to analyze phase transformation, Micro-Vickers to know the hardness, and shape-memory strain recovery testing using bending method. The microstructure of as-cast and as-homogenized is consist of β and another phase like α and γ with β:(α+ γ) phase fraction ratio of 92:8. After the heat treatment process, the microstructure of DQ showed needle-like and v-shaped structure that belongs to β’ martensite phase. Meanwhile, the microstructure of UQ showed needle-like v-shaped structure that belongs to β’ martensite phase and few phase like α and γ. , the microstructure of UQ showed needl-like and v-shaped β’ martensite phase and β phase. Alloy hardness for direct quenching was 155.61 HVN, up quenching was 179.76 HVN, and step quenching was 93.74 HVN. Strain recovery for direct quenching was 72.05%, up quenching was 74.15%, and step quenching was 81.95%."

"The main subject of the book is the continuum, field theoretic method of study of phase transformations in material systems. The method, also known as "phase field", allows one to analyze different stages of transformations on the unified platform. It has received significant attention in the materials science community recently due to many successes in solving or illuminating important problems. The book will address fundamentals of the method starting from the classical theories of phase transitions, the most important theoretical and computational results, and some of the most advanced recent applications."

"Predictive theories of phenomena involving phase change with applications in engineering are investigated in this volume, e.g. solid-liquid phase change, volume and surface damage, and phase change involving temperature discontinuities. Many other phase change phenomena such as solid-solid phase change in shape memory alloys and vapor-liquid phase change are also explored. Modeling is based on continuum thermo-mechanics. This involves a renewed principle of virtual power introducing the power of the microscopic motions responsible for phase change. This improvement yields a new equation of motion related to microscopic motions, beyond the classical equation of motion for macroscopic motions. The new theory sensibly improves the phase change modeling. For example, when warm rain falls on frozen soil, the dangerous black ice phenomenon can be comprehensively predicted. In addition, novel equations predict the evolution of clouds, which are themselves a mixture of air, liquid water and vapor."