Powder Jet Deposition Research Articles

Characteristics of hydroxyapatite film formed on human enamel with the powder jet deposition technique

This study aimed to create hydroxyapatite (HAp) film by powder jet deposition with manipulating the blasting nozzle above human enamel and to examine the microstructural and mechanical properties of the HAp film and the bonding strength at the interface between the HAp film and the enamel substrate. HAp particles calcinated at 1200°C with an average size of 4.7 μm were used. The HAp particles were mixed with carrier gas (N₂) to form an aerosol flow and was accelerated and blasted from the nozzle onto the enamel substrate at room temperature and atmospheric pressure. To evaluate the microstructure, scanning electron microscope (SEM) images of the surface and cross section of the HAp films and a three-dimensional profile of the HAp films were observed. To evaluate the mechanical properties, the micro-Vickers hardness and the bonding strength of the HAp films to the enamel substrate were measured. The deposition area of the HAp film was over 3 × 4 mm. The average and maximum thickness were about 30 and 40 μm, respectively. No significant difference was observed between the hardness of the HAp film and the enamel (p > 0.05). The bonding strength of the HAp film was the same as the bonding strength between composite resin and enamel. Compared with previous reports, wider and thicker HAp film was created on the enamel substrate successfully. The HAp film, which has same hardness with enamel and same bonding strength to the enamel with composite resin, would be a candidate as dental restorative materials.

130 パウダージェットデポジション法を用いた常温・常圧下での酸化物系セラミックスの成膜(材料力学III,一般講演)

130 パウダージェットデポジション法を用いた常温・常圧下での酸化物系セラミックスの成膜(材料力学III,一般講演)

Laser Assist Powder Jet Deposition

Amorphous NiP plate is used as a mold of precision optical parts owing to the superior machinability. In the amorphous NiP plate, some pores, whose diameter is about 100m, are generated occasionally. At present, the amorphous NiP plates with pore are rejected. However, because size of the mold becomes large in recent years, the possibility of pores becomes high. In addition, the cost of the amorphous NiP plate also becomes high. Therefore, reparation method of the pore in the amorphous NiP plate should be developed. In this paper, laser assist powder jet deposition is proposed as a reparation method of the amorphous NiP plate. And fundamental experiments are carried out.

Computational and Experimental Studies on Cavity Filling Process by Cold Gas Dynamic Spray

Time-dependent computational simulations on cavity filling process by cold gas dynamic spray and powder jet deposition process ranging from microscale to macroscale were carried out in order to give an insight for their advanced applications to joining, crack repair, and dental treatment. Shock wave appears in front of the substrate due to underexpansion of jet and in-flight particles interact with the shock wave before their impact. The relation between shock wave, cavity configuration, and particle in-flight behavior in supersonic jet has been discussed in detail. Based on numerical and experimental studies, it was found that when the shock wave covers up the cylindrical cavity, the cavity cannot be filled at all by deposited powders. Moreover, under the condition of shock wave appearing inside the cylindrical cavity, conical deposition was formed due to the secondary back flow jet along the cavity side wall. By adopting conical cavity, cavity can be filled completely resulting from the suppression of the secondary back flow jet along the cavity side wall.

441 パウダージェットデポジション法による酸化物系セラミックスの成膜とスプレー条件の最適化(固相微粒子による成膜技術とその応用,ものづくりにおける基礎研究と先端技術の融合)

441 パウダージェットデポジション法による酸化物系セラミックスの成膜とスプレー条件の最適化(固相微粒子による成膜技術とその応用,ものづくりにおける基礎研究と先端技術の融合)

Characteristics of the hydroxyapatite film deposited on human enamel: deposition of a ceramic film by powder jet deposition technique

A thick film of Hydroxyapatite (HAp) film is experimentally deposited on the enamel and dentin parts of a human tooth, using Powder Jet Deposition (PJD) technique. Micromorphologies of the created film, of the interface between the tooth and deposited film, and also of the tooth itself are studied and elaborated. Finally, possibility of a totally new kind of tooth treatment based on forming a new type of bond between the tooth and biomaterials through recalcification process is introduced.

Design of Double Nozzle Type Powder Jet Device Optimized for PJD

Thick films are needed in micro-electro-mechanical systems (MEMS) as insulation, piezoelectric and ferroelectric materials. To form the thick film, powder jet deposition (PJD) method has been proposed. In the PJD process, microparticles are sprayed out from nozzle under the conditions of room temperature and atmospheric pressure, and make a film on the substrate. We have developed a new jet mechanism of double-nozzle type, and reported its results previously [1]. In this study, we optimized the shape of the nozzle through investigating the influence of different dimensions and shape of the nozzle on the particles blasting velocity. As a result, it is found that nozzle diameter has a large affect on particles velocity.

1242 パウダージェットデポジッション法による機能性酸化物の成膜とその物性(J11-1 粒子付着・成膜プロセスと膜の機械的特性(1) コールドスプレー皮膜の諸特性,ジョイントセッション,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

1242 パウダージェットデポジッション法による機能性酸化物の成膜とその物性(J11-1 粒子付着・成膜プロセスと膜の機械的特性(1) コールドスプレー皮膜の諸特性,ジョイントセッション,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

D36 パウダージェットデポジション用二重ノズルの最適化(OS-7 研削・砥粒加工(2))

D36 パウダージェットデポジション用二重ノズルの最適化(OS-7 研削・砥粒加工(2))

210 2重ノズル型パウダージェットデポジション装置の開発(OS-7 ナノ・マイクロ加工)

210 2重ノズル型パウダージェットデポジション装置の開発(OS-7 ナノ・マイクロ加工)

Creating new interface between tooth and biomaterials using powder-jet technology

A powder-jet deposition (PJD) process utilizes high-speed collision adhesion phenomenon. We developed a dental PJD system, which was capable of precisely controlled blasting of ultra-fine hydroxyapatite (HA) particle under room temperature and atmosphere. Using the PJD system, we succeeded to make HA films on tooth substrates using HA. The growth of the HA film is saturated after about 1 s. The hardness of the deposited HA films was similar to human enamel.

Powder Jet Deposition of Ceramic Films(M^4 processes and micro-manufacturing for science)

Powder Jet Deposition of Ceramic Films(M^4 processes and micro-manufacturing for science)