Laser alloying and cladding for improving surface properties

Riabkina-Fishman, M.; Zahavi, J.

doi:10.1016/s0169-4332(96)00408-4

Cited by 45 publications

(13 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chattopadhyay [6] found excellent erosion resistance in a Stellite 6 plasmawelded overlay on cast-ferritic stainless steel (CA6NM) that is used as a turbine runner material. RiabkinaFishman and Zahavi [7] and Vilar [8] showed various approaches and advantages of laser surface alloying (LSA). The LSA (in which the surface chemical composition of a material is modified by adding a suitable proportion of alloying elements to the melt pool created with the laser beam) creates substantial savings in the consumption of strategic elements such as Cr, Ni, Mo, and Co, because less costly substrates can be surface alloyed for different applications.…”

Section: Introductionmentioning

confidence: 99%

Slurry Erosion Characteristics and Erosive Wear Mechanisms of Co-Based and Ni-Based Coatings Formed by Laser Surface Alloying

Shivamurthy

Kamaraj

Nagarajan³

et al. 2009

Metall Mater Trans A

View full text Add to dashboard Cite

In the present work, an attempt has been made to study the slurry erosion properties and operating erosive wear mechanisms of Co-based Stellite 6 and Ni-based Colmonoy 88 coatings, and also to list the conditions at which maximum and minimum erosion rates occur. Laser surface alloying (LSA) has been done on 13Cr-4Ni steels with commercial Co-based Stellite 6 and Ni-based Colmonoy 88 powders. Slurry erosion tests have been conducted on LSAmodified steels for a constant slurry velocity of 12 m/s and for a fixed slurry concentration of 10 kg/m 3 of irregular, sharp-edged SiO 2 particles with average sizes of 375 and 100 lm and at impingement angles of 30, 45, 60, and 90 deg. A mixed (neither ductile nor brittle) mode of erosion behavior for Stellite 6 coatings and a brittle mode of erosion behavior for Colmonoy 88 coatings were observed when these materials were impacted with particles with an average size of 375 lm, whereas only a brittle mode of erosion was observed for both Stellite 6 and Colmonoy 88 coatings when impacted with particles with an average size of 100 lm. Mainly, chip formation, chip fracture, microcutting, plowing, and crater lip and platelet formation were observed for Stellite 6 coatings and progressive fracture of carbides, carbide pullout and carbide/boride intact were observed for the case of Colmonoy 88 coatings.

show abstract

Section: Introductionmentioning

confidence: 99%

Slurry Erosion Characteristics and Erosive Wear Mechanisms of Co-Based and Ni-Based Coatings Formed by Laser Surface Alloying

Shivamurthy

Kamaraj

Nagarajan³

et al. 2009

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…The energy needed to heat and melt the particle is proportional to : [3] where P ϭ thermal power flowing into the particle, ϭ interaction duration until melting, r p ϭ powder particle radius, ϭ specific mass density of the particle, c p ϭ specific heat capacity, T m ϭ melting temperature, and ⌬H m ϭ latent heat of melting. Figure 10 shows the distribution N ϭ f (2r p ) of the particle diameters in the powder used in this investigation.…”

Section: A Particle Heating By the Melt Frontmentioning

confidence: 99%

“…[3] is applied here in order to estimate the duration for heating and melting a particle for a given heat flux.…”

Section: A Particle Heating By the Melt Frontmentioning

confidence: 99%

“…It must also be borne in mind that a change in incident power P (or heat flux) leads only to an inversely proportional change in melting time , Eq. [3]. …”

Section: A Particle Heating By the Melt Frontmentioning

confidence: 99%

“…THE process of laser cladding has been the subject of scientific research and commercial applications since the late 1970s, [1][2][3][4][5][6] in particular, investigating the track cross section, absorption, substrate dilution, and mechanical properties. Moreover, crack and pore formation are essential phenomena to be avoided, but highly depend on the metallurgical properties of the different materials and alloys applied.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Melt-solid interactions in laser cladding and laser casting

Gedda

Kaplan

Powell

2005

Metall Mater Trans B

View full text Add to dashboard Cite

Experimental data in conjunction with mathematical models are used to explain various aspects of laser casting and laser cladding by the preplaced powder method. For increasing speed, the data can be distinguished between substrate melting, dilution-free clad bonding, bond-free casting, and poor contact breaking the melt track into spheres. Results include a thermodynamic explanation of the wide range of process parameters over which dilution-free clad deposits can be produced, as the process switches from heating of the insulating powder to additional cooling when the melt front reaches the substrate. Also, the interaction of the melt pool with the powder bed is analyzed to identify why laser castings have microscopically uneven surfaces and do not bind with the substrate. The advancement of the melt front through the powder layer is governed by heating, melting, and incorporation of each individual grain. Although most powder grains are in the small size range for the case studied, the few particles up to a factor 3 larger delay and therefore govern the front advancement due to much slower melting and surface tension driven incorporation, depending on the particle size in a nonlinear manner.

show abstract