10 Things You Should Ask About ISF

Why Use REM?

Feature REM ISF® Chemically accelerated nonabrasive tumbling Grinding Honing Abrasive Vibratory
Unique Features Proven for white layer removal, Loss of Lubrication performance, extended time on wing, reproducible, transparent process Fast removal, aggressive, shape correction Improves roundness, generates very smooth surfaces Bulk finishing, less precise
Surface Finish Quality Ra < 4 µin (0.1 µm), Isotropic 8–12 µin Ra, Directional Ra < 4 µin, Directional 8–16 µin Ra, Non-Directional
Material Removal Control Low Material Removal, Highly Controlled Moderate Material Removal, Moderately controlled Low Material Removal, Controlled Moderate to High Material Removal, Minimal Control
Effect on Part Geometry Preserves geometry Preserves geometry Preserves geometry Can alter geometry, risk of edge rounding
Stock Removal 1–20 µm, tightly controlled 10–100 µm typical 2–20 µm typical 5–50 µm, less controlled
Reproducibility High, parameter-driven, batch consistency Operator dependent, variable Operator dependent, variable Moderate, batch dependent
Surface Topography Isotropic, non-directional Directional Directional Non-directional, non-uniform
Mass Finishing Yes No No Yes
Process Customization Yes Limited Limited Limited
Cost Cost-effective for small orders or Mass Finishing High initial/tooling, moderate per part High initial/tooling, moderate per part Low–moderate, cost-effective for high volume

ISF Frequently Asked Questions

  1. What’s the process for initiating a new ISF project, and what information do you require?
  2. How does your pricing structure work, and what factors influence the cost of ISF processing?
  3. What are your typical lead times for ISF processing, and how do you manage production schedules?
  4. How much material does the ISF process remove?
  5. What are the size and shape limitations for parts that can be processed with ISF?
  6. What alloys can your process be applied to?
  7. Is the ISF process an etching chemical process, and how does it differ from other chemical treatments?
  8. Does the ISF process introduce Hydrogen Embrittlement (HE)?
  9. Who else is using the ISF process, and what industries are benefiting from it?
  10.  What measures are in place to ensure consistent results and tight process control across large production runs?

 

1. What’s the process for initiating a new ISF project, and what information do you require?
To initiate an ISF project, we begin with an engineering project. This crucial first step allows us to tailor the ISF process to your specific parts and performance requirements. We’ll need:

  • Part drawings
  • Material specifications
  • Target surface finish and performance goals

This engineering phase ensures process optimization and validation before moving to production, whether in our Job Shop Services (JSS) or with an in-house installation. Contact us to discuss your project’s feasibility and requirements.

 

2. How does your pricing structure work, and what factors influence the cost of ISF processing?

Our ISF processing pricing varies depending on the project’s scope and requirements. Here’s a breakdown:

Initial Engineering Projects:

These projects involve process development, testing, and validation to ensure optimal results for your specific parts. The main factor influencing the price will be whether we can process all parts in a single batch, or if you prefer smaller batches with review meetings to adjust the process. Pricing is typically based on engineering time, material costs, and testing requirements. This initial investment ensures a tailored and validated ISF process for your production needs.

Production Runs (JSS or In-House):

For ongoing production, pricing is influenced by:

  • Part geometry and complexity.
  • Production volume.
  • Tooling requirements.

Larger production runs often benefit from economies of scale.

We provide detailed quotations after evaluating your specific needs. Contact us with your project details to receive a customized pricing estimate.

 

3. What are your typical lead times for ISF processing, and how do you manage production schedules?

  • Chemicals: 3-5 days
  • JSS (Job Shop Services): 15 days
  • Tooling: 30 days
  • Media: 4-12 weeks
  • Equipment: 16-20 weeks

All lead times are in business days. Orders are processed on a FIFO (First-In, First-Out) basis. However, we do have expedite options available for a fee. Once the parts and PO have arrived, these options can be discussed. For precise lead time estimates on your specific project, please contact us.

 

4. How much material does the ISF process remove?

While the material removed is part-specific, we can use a general rule to estimate your part’s requirements. To estimate material removal, we first need to understand the relationship between Ra (average roughness) and Rz (maximum height of the profile). Rz represents the maximum peak-to-valley height, while Ra is the average roughness. A common practice is to estimate Rz by multiplying the Ra value by a factor of 7 to 10, depending on the surface texture. For a conservative estimate, we use a factor of 10.
Examples:

Initial Ra 16 µin:

  • 16 µin x 10 = 160 µin (0.00016 in) [This estimates the initial Rz value]

To achieve a target Ra of 4 µin:

  • The target Rz would be approximately 40 µin (0.00004 in)
  • With an initial Ra of 16 µin, approximately 0.00012 inches of material removal per surface is required.

We can tailor the process to stop at any point, based on your specific tolerance requirements. For a more precise estimation based on your specific part, please contact us.

 

5. What are the size and shape limitations for parts that can be processed with ISF?

  • Size Range: We routinely handle parts from very small, dime-sized components to large parts 7 feet in diameter
  • Weight Range: Our equipment can process parts up to 3000 lbs
  • Shape Considerations: We excel at processing complex external geometries. However, our process has limitations in the surface finish improvements we can achieve within certain internal geometries. To determine if your specific parts are suitable for the ISF process, we recommend providing us with:
    • Part drawings or CAD models
    • Dimensions and weight specifications

We can then assess the feasibility and provide a customized solution. For exceptionally large or complex parts, we can also discuss potential custom solutions.

 

6. What alloys can your process be applied to?

The ISF process is highly versatile and can be applied to a wide range of metal alloys, including:

  • Steels: Including carbon steels, alloy steels, stainless steels, and tool steels
  • Nickel Alloys: Such as Inconel, Hastelloy, and other high-temperature alloys
  • Titanium Alloys: Including various grades of titanium used in aerospace and medical applications

Our team has extensive experience working with diverse materials, and we can assess the suitability of the ISF process for your specific alloy. If you have any questions regarding a specific alloy, please contact us.

 

7. Is the ISF process an etching chemical process, and how does it differ from other chemical treatments?

The ISF process utilizes a controlled chemical reaction to form a phosphate conversion coating on the metal surface. This coating is then mechanically removed by specialized media, resulting in a highly refined surface. While a small amount of material is removed during this mechanical action, the chemical component primarily facilitates the formation of the coating, not the direct removal of the base material.
This process differs from chemical etching treatments in several ways:

  • Precision: ISF offers highly controlled material removal, ensuring precise surface refinement
  • Isotropic Finish: It creates an isotropic (non-directional) surface texture, unlike directional patterns left by many other chemical processes
  • Chemical-Mechanical Synergy: ISF combines a controlled chemical conversion with mechanical action for optimal results
  • Surface Refinement: It’s focused on improving surface integrity and performance, not just material removal
  • Consistency: The process has been refined over decades to provide a very high level of consistency

This combination of factors makes ISF a unique and highly effective surface finishing solution.

 

8. Does the ISF process introduce Hydrogen Embrittlement (HE)?

Our ISF process is specifically designed to eliminate the risk of Hydrogen Embrittlement (HE). Here’s how:4

  • Mild Phosphating Solutions: We use mildly acidic phosphating solutions that are formulated to avoid causing HE
  • Hydrogen Scrubbers: Our chemical products include hydrogen scrubbers, which further mitigate the risk of hydrogen absorption
  • Raw Material Quality: We use food-grade raw materials to ensure product purity and minimize potential contaminants
  • Testing Support: We offer full HE testing support to verify the integrity of your components after processing

 

9. Who else is using the ISF process, and what industries are benefiting from it?

The ISF process is utilized by leading companies in critical industries, particularly Aerospace and Power Generation:

  • Aerospace:
    • Aerospace clients rely on ISF to enhance the fatigue life and reliability of critical components, such as gears and bearings
    • The process extends component “time on wing” and provides repair capabilities, leading to reduced maintenance and operational costs
  • Power Generation:
    • Power generation companies, especially in the wind turbine and gas turbine sectors, use ISF to enhance the durability of components operating in demanding environments, such as turbine blades, gears, and bearings
    • ISF improves the reliability of these critical parts, reducing downtime and maintenance costs

While we maintain confidentiality with our clients, we can provide specific examples of how the ISF process has improved the performance and lifespan of components within these industries upon request.

 

10. What measures are in place to ensure consistent results and tight process control across large production runs?

We maintain rigorous process control and ensure consistent results through several key measures:

  • AS9100 Certification: Our AS9100 certification demonstrates our commitment to quality management and standardized processes.
  • Detailed Work Instructions and Training Logs: Each operation is governed by detailed work instructions, and our operators undergo comprehensive training, with thorough training logs maintained. This ensures that every step is executed consistently.
  • Automated Equipment: Our equipment offers a high level of automation, guaranteeing accurate and repeatable cycle times, which is crucial for consistent surface finish results.

These measures, combined with our decades of experience, ensure that we deliver consistent and high-quality results for every production run.

About Chris

Chris Mershon helps clients in the Aerospace and Power Generation industries who are seeking innovative solutions to improve component performance, reduce downtime, or enhance reliability. He focuses on helping them achieve success through REM’s advanced surface finishing technologies. With 20 years of experience at REM, Chris has a deep understanding of REM’s capabilities and how they can be applied to solve specific problems. He specializes in providing tailored solutions for vertical lift, fixed-wing, and space applications within the aerospace sector, as well as extending the life of wind turbine gears (up to 2-3 MW) and improving the aerodynamics of gas turbine blades through reduced turbulence, improved flow efficiency within the power generation sector. To discuss how REM can optimize your components and improve your bottom line, contact Chris.