Aerospace

The aerospace/aviation industry requires the highest standards of manufacturing and part quality.  Component failure is simply not an option on flight-critical aero-engine and power transmission components.

REM’s industry-leading isotropic superfinishing technology, the ISF® Process, is the specified surface finishing/surface polishing process for a wide range of aerospace power transmission and aero-engine applications because of its exceptional performance benefits; its proven process reliability and repeatability over decades of processing runs and tens of thousands of flight-critical components; and its range of peer-reviewed, published technical papers/studies.

Aerospace Gearing

The ISF Process has been proven to be capable of maintaining the tight profile tolerances of spur, helical, and spiral bevel aerospace gearing for a wide range of rotorcraft, VTOL (vertical takeoff and lift), and fixed-wing applications, while imparting significant increases to component life/operating safety margin linked to gear failure modes such as contact fatigue, wear, and scuffing.  The technology has been proven to outperform incumbent surface finishing technologies in extreme condition and loss-of-lubricant (LOL)/oil-out testing such as black oxide and honing in multiple third party technical studies.  The generated ISF® Surface allows for additional component and system design options due to the improved load distribution that it offers. Furthermore, the ISF Process can finish multiple part features simultaneously (example – gear flanks and bearing surfaces), thereby providing the potential to reduce manufacturing/operating steps and manufacturing costs.  Many of these benefits apply to other, non-gear, power transfer components as well.

Additionally, the ISF Process has been proven to be capable of repairing used, lightly damaged flight-critical gearing allowing otherwise scrap components to be put back into service.  Technical studies have shown that these ISF Process repaired gears equal or exceed the fatigue life performance of new, non-ISF Processed gears.

Airfoils and Blisks

When applied to airfoil and airfoil like components (including blisks) in aero-engine/jet engine applications, REM’s ISF Process can achieve extremely low surface roughness finishes (< 2µin / 0.5 µm ) while maintaining critical blade geometries including leading edges, trailing edges, blade tips, and dovetails.  The ISF Surface has also been shown to be capable of aiding in maintaining blade cleanliness in addition to the obvious laminar flow property improvements and derivative system efficiency increases (especially during engine acceleration events).

Common Aerospace Applications for the ISF Process

Component Benefits for Aerospace Applications

Production Benefits for Aerospace Applications

  • Potential to Eliminate Honing
  • Potential to Reduce Manufacturing Steps
  • Potential to Reduce Grinding Surface Finish Requirements
  • Potential to Eliminate Black Oxide
  • Potential to Reduce or Optimize Deburring and Chamfering Operations
  • Improved Component Inspection Capability

Common Aerospace Alloys REM can Assist with

Common Aerospace Component Forming Techniques the ISF Process can Improve

  • Ground (Machined)
  • Milled
  • Turned
  • EDM
  • Pressed and Sintered

 

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.

Interested in learning more, ready to start a project, or have an application that you don’t see listed here?  Contact us today to see how we can help solve your surface finishing/polishing needs.