Influence of Laser Heat Treatment on Fracture Strength of Ceramic Thin Film

2012 ◽  
Vol 566 ◽  
pp. 145-149
Author(s):  
Hirotaka Tanabe ◽  
Keiji Ogawa ◽  
Yui Izumi ◽  
Tohru Takamatsu ◽  
Heisaburo Nakagawa ◽  
...  

In our previous study, it has been shown that improvement of the adhesive strength and substrate hardness of ceramic coated steels without compromising the film hardness can be achieved by applying laser quenching. In the present research, in order to demonstrate further development of this method, the fracture strength of laser-irradiated ceramic thin films (CrAlN, TiAlN and CrN) was investigated by sphere indentation testing. To prevent heat-induced changes in the substrate hardness, a cemented carbide WC-Co rather than steel was used as substrate material. While the fracture strength of each film decreased significantly through furnace heat treatment, it remained almost unchanged in case of the laser irradiated films. Laser quenching has been shown to effectively reduce the fracture strength loss of the ceramic thin films in coated steels.

2009 ◽  
Author(s):  
Hirotaka Tanabe ◽  
Tohru Takamatsu ◽  
Tetsuro Hamada

2010 ◽  
Vol 123-125 ◽  
pp. 1223-1226 ◽  
Author(s):  
Jin Woo Yi ◽  
Sang Bok Lee ◽  
Jin Bong Kim ◽  
Sang Kwan Lee ◽  
Ki Hyeon Kim ◽  
...  

In order to develop an effective near-field electromagnetic (EM) wave absorber, we have fabricated polymeric thin films including hollow metallic microfibers. Hydrolyzed polymer micro fibers (~2.5 ㎛) were used as a substrate material for the electroless metal plating. Nickel and subsequent Fe-Co metal layers were coated on the surface of activated polymer fibers and then heat treatment for the hollow structure as well as the densification of metallic layers was performed under the Argon atmosphere. Unlike conventional particulate or flaky metal powders, these fibers can play a significant role in elevating the magnetic property of polymer films, resulting in the increased efficiency of EM absorbing properties. In addition, their hollow structure can also lower their apparent density. SEM and EDS analysis were carried out to verify the morphology and metal compositions. Polymeric thin films containing hollow Ni/Fe-Co micro fibers were prepared to investigate the effect of metal compositions, filler distribution and heat treatment conditions on not only the near-field absorbing performance, but also magnetic properties such as permeability and magnetization. For the measurement of near-field EM absorbance in the frequency range of ~6GHz, micro strip line and network analyzer were used.


2012 ◽  
Vol 157-158 ◽  
pp. 175-180 ◽  
Author(s):  
Hirotaka Tanabe ◽  
Keiji Ogawa ◽  
Takuya Saraie ◽  
Mitsuhiro Gotoh ◽  
Hideki Hagino ◽  
...  

In order to investigate the effectiveness of laser quenching for ceramic coated steels, 2 kinds of ceramic coated specimens of CrAlN and TiAlN were prepared, and the laser quenching experiments under various irradiation conditions were carried out. The influence of laser irradiation on the substrate hardness, film hardness and adhesive strength were investigated. Because of the high heat absorption of CrAlN and TiAlN films when compared to TiN, it was possible to quench the substrate effectively without any absorbent material for these specimens, although an absorbent was required for TiN coated specimen. The quenched area on the cross section of the substrate of CrAlN coated specimen was larger than that of TiAlN coated specimen. The difference of the quenched area could be explained by the difference of the heat absorption of these films. It was also possible to improve the adhesive strength of these films by laser irradiation. Although the film hardness decreased considerably by furnace quenching for ceramic coated steels, film hardness did not decrease by laser irradiation. It was concluded that the improvement of the adhesive strength and substrate hardness without the decrease of film hardness was achieved by laser quenching for CrAlN and TiAlN coated specimens.


2012 ◽  
Vol 566 ◽  
pp. 427-430 ◽  
Author(s):  
Hirotaka Tanabe ◽  
Keiji Ogawa ◽  
Yui Izumi ◽  
Takuya Saraie ◽  
Mitsuhiro Gotoh ◽  
...  

In our previous study, it has been shown that improvement of the adhesive strength and substrate hardness of ceramic coated steels without compromising the film hardness can be achieved by applying laser quenching. In the present research, in order to quench a larger area of ceramic coated steel uniformly and efficiently, a high power diode laser equipped with a galvano-scanner unit was used in the laser heat treatment process. The scanning laser irradiation conditions to achieve uniformly quenched substrates without any surface damage were investigated for 3 kinds of ceramic-coated steels: CrAlN, TiAlN and CrN. The film hardness and adhesive strength of the laser irradiated regions were evaluated. It is shown that scanning laser quenching after coating effectively improved the mechanical properties for larger area of ceramic-coated steels.


Author(s):  
R. M. Anderson

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.


Author(s):  
Karren L. More

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.


Author(s):  
J.M. Schwartz ◽  
L.F. Francis ◽  
L.D. Schmidt ◽  
P.S. Schabes-Retchkiman

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.


2008 ◽  
Author(s):  
Xiaomei Guo ◽  
Kewen Kevin. Li ◽  
Xuesheng Chen ◽  
Yingyin Kevin. Zou ◽  
Hua Jiang

1992 ◽  
Vol 7 (11) ◽  
pp. 3065-3071 ◽  
Author(s):  
Peir-Yung Chu ◽  
Isabelle Campion ◽  
Relva C. Buchanan

Phase transformation and preferred orientation in ZrO2 thin films, deposited on Si(111) and Si(100) substrates, and prepared by heat treatment from carboxylate solution precursors were investigated. The deposited films were amorphous below 450 °C, transforming gradually to the tetragonal and monoclinic phases on heating. The monoclinic phase developed from the tetragonal phase displacively, and exhibited a strong (111) preferred orientation at temperature as low as 550 °C. The degree of preferred orientation and the tetragonal-to-monoclinic phase transformation were controlled by heating rate, soak temperature, and time. Interfacial diffusion into the film from the Si substrate was negligible at 700 °C and became significant only at 900 °C, but for films thicker than 0.5 μm, overall preferred orientation exceeded 90%.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshifumi Imajo ◽  
Takashi Suemasu ◽  
Kaoru Toko

AbstractPolycrystalline Ge thin films have attracted increasing attention because their hole mobilities exceed those of single-crystal Si wafers, while the process temperature is low. In this study, we investigate the strain effects on the crystal and electrical properties of polycrystalline Ge layers formed by solid-phase crystallization at 375 °C by modulating the substrate material. The strain of the Ge layers is in the range of approximately 0.5% (tensile) to -0.5% (compressive), which reflects both thermal expansion difference between Ge and substrate and phase transition of Ge from amorphous to crystalline. For both tensile and compressive strains, a large strain provides large crystal grains with sizes of approximately 10 μm owing to growth promotion. The potential barrier height of the grain boundary strongly depends on the strain and its direction. It is increased by tensile strain and decreased by compressive strain. These findings will be useful for the design of Ge-based thin-film devices on various materials for Internet-of-things technologies.


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