**NTST Services: **************************** **************************** High & low production Materials engineering Parametric testing Coatings & materials R&D Applications development Mat. characterization Mat. performance eval. Technical consulting: materials & processes Analytical studies gas dynamics particle dynamics thermochemistry heat transfer statistics **************************** **************************** NTST Services:**

*Latest NTST News:*

*New Hi-Tech Coatings:*

**Boron Carbide (B4C)**

**Silicon Carbide (SiC)**

**Aluminum Nitride (AlN)**

**Cubic Boron Nitride (c-BN)**

**Hex Boron Nitride (h-BN)**

** ****
****Silicon Nitride (Si3N4)**

**Titanium Nitride (TiN)**

**Fire Prevention**

** Download the "New Coatings Brochure" for a short description of the above ****coatings or download other specific products at the bottom of this home page**

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**Click on the PRODUCTS tab above**

**Contact Information**

**call:**

**702-449-2154**

**email:**

**dominic@nevadathermalspray.com**

**or ****click for:**

**Nevada Thermal Spray
Tech.**

**4842 Judson Avenue, Suite
115**

**Las Vegas, NV
89115**

**Thermal spray coatings are**

**used in over 50 industries**

# Analytical Modeling

**To enhance usage of the thermal spray processes, a better physical understanding of the processes is required, which involves a synergistic mix of analytical
and experimental studies to optimize the thermal spray process as shown below in Figure 1. **

**Better understanding of coating formation can lead to the development of optimum thermal spray coatings for future industrial applications. Due to the
complexity of the thermal spray processes, NTST computational services are offered in the fields of gas dynamics, particle dynamics, coating formation, materials technology, heat transfer, fluid
flow, thermal-hydraulics, and thermochemistry.**

**NTST maintains a database of computer programs for statistics, plasma physics, particle dynamics, coating dynamics, and chemistry for use in design and
analysis. **

**Figure 1. Optimization of the Thermal Spray Processes**

*Gas Dynamics
Modeling*

The mass, momentum, and energy conservation equations are solved assuming a two dimensional, axisymmetric model for the
thermal spray gun. The input to the code involves transport and thermodynamic gas properties, the spray gun geometry, and the system operation parameters. Typical output (e.g. Figure 2) from this
model includes temperature, enthalpy, velocity, and viscosity profiles as a function of radial and axial position in the column and plume regions of a spray gun.

**Figure 2. Analytical prediction of gas temperature and velocity**

*Particle Dynamics*

**The particle dynamics code uses the temperature and velocity fields generated by the gas dynamics code
to calculate the dynamics of particles injected into the plume. The primary result of the code is a description of the injected particle vaporization rate, average temperature and velocity as a
function of position in the gas plume. The code calculates the histories of the injected particles one at a time, and accumulates the results for as many particles as stipulated.**

**For each particle injected, the specfied initial conditions are the injection location, the velocity,
and the diameter. Also specified are the particle material properties. ****Typical output from this model includes particle temperature, velocity,
and state as a function of position in the plume.**

**Figure 3 illustrates the calculated tungsten particle temperature
as a function of location in the plume.**

**Figure 3. Analytical prediction of particle temperature**

*Coating Dynamics*

Using the particle dynamics calculations, a particle plume distribution is established to study coating morphology as a function of the various process parameters. Attributes such as thickness,
hardness, porosity, deposition efficiency, tensile strength, and oxide content can be calculated.*
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