MoSi2 laser cladding—elaboration, characterisation and addition of non-stabilized ZrO2 powder particles

One of the well-known methods for increasing wear resistance, especially for friction pairs, is surfacing wear-resistant materials on the working surfaces of mating parts [1, 2, 3]. Less expensive grades of steel can be used as the main material in the manufacture of parts, and the surfacing materials in this case must have increased characteristics: mechanical, corrosion and radiation resistance, heat resistance, wear resistance; good anti-friction properties, i.e. more expensive [4, 5]. This significantly reduces the cost of manufacturing or repairing parts, especially in mass production, since cheap grades of steel are used for their manufacture [5, 6]. Improvement of parts by gas powder laser cladding is carried out in shipbuilding, energy, oil and gas and mining industries, in the aviation industry and others. Note that although the method of coating appeared a long time ago, various methods of applying surfaced coatings are still being developed and refined [5,6]. In gas powder laser cladding, coatings are obtained by forcing the powder flow directly into the laser radiation zone [7, 8]. The powder particles are heated in the laser radiation zone and fall on the treated surface (substrate). It is known that the powder particles melt only after they hit the substrate [3, 4], but at the same time the surface layer of the base metal melts. After heating and melting the substrate, a liquid melt bath is formed, which, along with the molten powder, contains a significant part of the base metal components [7, 8]. The intensity of saturation of the surfacing metal with the substrate components is characterized by the proportion of the base metal in the cross section of the track, which is determined by the mixing ratio [9, 10, 11]. It is equal to the ratio of the area of the melted substrate to the sum of the areas of the melted substrate and the track as a percentage and depends on the cladding modes, which is determined after metallographic studies of the structure of protective coatings [8].

Download Full-text

The behavior of powder particles in coaxial laser cladding

10.1117/12.871209 ◽

2010 ◽

Author(s):

Nan Yang ◽

Hua-jun Dong ◽

Ping Hu

Keyword(s):

Laser Cladding ◽

Powder Particles

Download Full-text

A theoretical model for laser and powder particles interaction during laser cladding

Journal of Materials Processing Technology ◽

10.1016/s0924-0136(02)00433-8 ◽

2002 ◽

Vol 128 (1-3) ◽

pp. 106-112 ◽

Cited By ~ 78

Author(s):

Yunchang Fu ◽

A. Loredo ◽

B. Martin ◽

A.B. Vannes

Keyword(s):

Theoretical Model ◽

Laser Cladding ◽

Powder Particles

Download Full-text

Investigation and Modeling of the Process of Formation of the Pad Weld and its Microstructure during Laser Cladding by Radiation of High Power Fiber Laser

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.682.160 ◽

2014 ◽

Vol 682 ◽

pp. 160-165 ◽

Cited By ~ 15

Author(s):

Gleb Turichin ◽

V.V. Somonov ◽

Olga G. Klimova-Korsmik

Keyword(s):

Fiber Laser ◽

Laser Cladding ◽

High Power ◽

Transition Layer ◽

Theoretical Solution ◽

Gas Jet ◽

Powder Particles ◽

Cladding Mode ◽

Metal Properties ◽

The Impact

The article gives theoretical solution of the problem of powder particles heating and their transfer to the substrate, considering the impact of transporting gas jet incidence on the substrate. The article also describes the research of layer microstructure, deposited by high power fiber laser cladding, and result of analysis of the dependence metal properties from the transition-layer cladding mode.

Download Full-text

The Use of ZrO2 Waste for the Electrolytic Production of Composite Ni–P–ZrO2 Powder

Materials ◽

10.3390/ma14216597 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6597

Author(s):

Jolanta Niedbała ◽

Magdalena Popczyk ◽

Grzegorz Benke ◽

Hubert Okła ◽

Jadwiga Gabor ◽

...

Keyword(s):

Phase Structure ◽

Composite Powder ◽

Nickel Ions ◽

Zro2 Powder ◽

Distribution Of Elements ◽

Amorphous Compounds ◽

Powder Particles ◽

Flow Through ◽

Oxide Particles ◽

Crystalline Component

Ni–P–ZrO2 composite powder was obtained from a galvanic nickel bath with ZrO2 powder. Production was conducted under galvanostatic conditions. The Ni–P–ZrO2 composite powder was characterized by the presence of ZrO2 particles covered with electrolytical nanocrystalline Ni–P coating. The chemical composition (XRF method), phase structure (XRD method) and morphology (SEM) of Ni–P–ZrO2 and the distribution of elements in the powder were all investigated. Based on the analyses, it was found that the obtained powder contained about 50 weight % Zr and 40 weight % Ni. Phase structure analysis showed that the basic crystalline component of the tested powder is a mixed oxide of zirconium and yttrium Zr0.92Y0.08O1.96. In addition, the sample contains very large amounts of amorphous compounds (Ni–P). The mechanism to produce the composite powder particles is explained on the basis of Ni2+ ions adsorption process on the metal oxide particles. Current flow through the cell forces the movement of particles in the bath. Oxide grains with adsorbed nickel ions were transported to the cathode surface. Ni2+ ions were discharged. The oxide particles were covered with a Ni–P layer and the heavy composite grains of Ni–P–ZrO2 flowed down to the bottom of the cell.

Download Full-text

On the Origin of the Microscystalline Structure in Rapidly Solidified IN-100 Powder

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100078821 ◽

1977 ◽

Vol 35 ◽

pp. 260-261

Author(s):

J. M. Walsh ◽

K. P. Gumz ◽

J. C. Whittles ◽

B. H. Kear

Keyword(s):

The Other ◽

Coarse Grained ◽

Microcrystalline Structure ◽

Routine Examination ◽

Atomization Process ◽

Centrifugal Atomization ◽

Splat Quenching ◽

Powder Particles ◽

Dendritic Microstructures ◽

Rapidly Solidified

During a routine examination of the microstructure of rapidly solidified IN-100 powder, produced by a newly-developed centrifugal atomization process1, essentially two distinct types of microstructure were identified. When a high melt superheat is maintained during atomization, the powder particles are predominantly coarse-grained, equiaxed or columnar, with distinctly dendritic microstructures, Figs, la and 4a. On the other hand, when the melt superheat is reduced by increasing the heat flow to the disc of the rotary atomizer, the powder particles are predominantly microcrystalline in character, with typically one dendrite per grain, Figs, lb and 4b. In what follows, evidence is presented that strongly supports the view that the unusual microcrystalline structure has its origin in dendrite erosion occurring in a 'mushy zone' of dynamic solidification on the disc of the rotary atomizer.The critical observations were made on atomized material that had undergone 'splat-quenching' on previously solidified, chilled substrate particles.

Download Full-text

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139834 ◽

1995 ◽

Vol 53 ◽

pp. 692-693

Author(s):

Yun Lu ◽

David C. Joy

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

High Resolution ◽

Morphological Development ◽

Early Hydration ◽

X Ray ◽

Blended Cements ◽

Powder Particles ◽

Chemical Wastes ◽

Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

Download Full-text

Shock consolidation of Ni-Ti alloy powder

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143730 ◽

1986 ◽

Vol 44 ◽

pp. 430-431

Author(s):

Naresh N. Thadhani ◽

Thad Vreeland ◽

Thomas J. Ahrens

Keyword(s):

Alloy Powder ◽

Amorphous Material ◽

Ti Alloy ◽

Two Phase ◽

Near Surface ◽

Optical Micrograph ◽

Shock Compaction ◽

Powder Particles ◽

Ti Powder ◽

Rapidly Solidified

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.

Download Full-text