5 Reasons why Ultrasonic Impact Treatment is Your Best Option for Metal Improvement

Industries such as transportation, aerospace, mining, military, and infrastructure that rely so heavily on the resilience of their structures, require a metal improvement technique that is not only superior in terms of results and longevity, but can also be performed quickly, cleanly and without restrictive costs.  Ultrasonic Impact Treatment utilizes the strength of ultrasonic energy to achieve these goals more effectively than any metal improvement technique to come along prior to its availability.

Here are 5 reasons why ultrasonic impact treatment exceeds conventional peening, grinding or other traditional metal improvement methodologies:

1. Improved Surface Condition

Poor surface conditions lead to deteriorations in the material, which create microscopic stress concentrations that reduce fatigue strength and lead to eventual cracking.  By introducing compressive stresses at the surface, UIT creates a smoother, hardier surface condition that’s more resistant to stress and corrosive climactic or chemical elements.  This metal improvement at the surface helps to prevent fatigue failure, thereby extending the useable life of the component and markedly reducing replacement and repair costs. 

2. Refortified Intergranular Composition

Beneath the surface, UIT lends to metal improvement by refortifying the size, shape and orientation of grains within the material.  As such, microscopic flaws that would otherwise grow to detrimental levels are combated in their earliest stages, and weakened components are transformed back to their strongest composition.  Once again fatigue life is increased and the need for more extensive repairs down the line is alleviated.

3. Alleviation of Tensile Stresses

Repetitive cyclic loading beyond given thresholds creates destructive tensile stresses, which propagate across the surface and lead to disastrous results.  Ultrasonic impact technology drives tensile stresses deeper than any competitive metal improvement treatment to a depth of 12 mm.  By removing tensile stresses to such a superior depth, UIT again outperforms conventional methods of improving metal strength more effectively and for a longer period of time. 

4. Extended Fatigue Life

By improving surface condition, creating a more corrosion-resistant material, strengthening metal at the grain structure, removing tensile stresses and introducing fortifying compressive stresses; metal improvement via ultrasonic impact treatment greatly extends fatigue life in critical components.  Beyond the financial benefits, the confidence and peace-of-mind delivered in the knowledge that structures, such as aircraft, mining equipment, offshore platforms, and heavy machinery are safe and reliable provides immeasurable advantages over less effective methods of metal improvement. 

5. Speed & Ease of Application

Through its patented ultrasonic impact tool, UIT can be applied faster and more conveniently than other metal improvement methodologies.  The portability and configurability of the tool allows it to access formerly hard-to-reach areas without the need to disassemble components and put a lengthy stop in production.  Furthermore, the lack of debris means less time required to section off areas and cleanup following service.  The elimination of these previous drawbacks means ultrasonic impact treatment is not only faster and more affordable, but also reduces downtime – all of which contribute to a healthier bottom line.

Structural solidity, extended fatigue life, less downtime, increased profit margins and improved confidence all make ultrasonic impact treatment your best solution when considering metal improvement processes. 

Combating Steel Fatigue with Ultrasonic Impact Treatment

Steel fatigue occurs when a metal structure or component is subjected to repeated loading and unloading of stress on a specific part (similar to bending a paper clip or staple back and forth repetitively until it breaks).  When this process, also known as cyclic loading, exceeds a specific limit, tensile cracks form on the surface and alters microscopic grains within the metal which ultimately lead to fatigue failure if left untreated.  Outside of replacing the metal, Ultrasonic Impact Treatment from Applied Ultrasonics has emerged as the most effective method of combating steel fatigue due to its ability to improve surface quality, force detrimental tensile stresses deep within the material, and reform the grains that comprise the structure of the metal. 

*Example of cyclic loading and its effect on steel fatigue.

Preventing Stress Corrosion Cracking with Ultrasonic Impact Treatment

Stress corrosion cracking occurs when a susceptible material is exposed to a corrosive environment and tensile stresses above a given threshold.  Effective treatment requires one of these three contributors be alleviated before crack propagation begins and catastrophic  failure ensues.  The ability of Ultrasonic Impact Treatment to enhance surface quality while removing tensile stresses and fortifying susceptible metals on a granular level has made it the preferred method of treatment across various industries vulnerable to stress corrosion cracking.

Surface Quality and Stress Corrosion Cracking

One of the most troubling issues with stress corrosion cracking is that it can proceed unnoticed to the point of failure.  The chemical environment that leads to SCC is often only mildly corrosive to the material otherwise.  This commonly results in no visual symptoms of fatigue occurring while the metal is approaching the point of failure.

Understanding and recognizing chemicals that react corrosively when introduced to specific metals is key to preventing stress corrosion cracking prior to development.  If the component is already in place and surface corrosion has begun, or is suspected to have begun and replacement is cost prohibitive (which is often the case), it’s vital to remove corrosion and restore the surface to its optimal condition. 

Ultrasonic Impact Technology harnesses the power of ultrasonic energy to not only improve surface quality more effectively than past methods, such as grinding or hammer peening, but also to improve corrosion resistance in susceptible metals, thereby extending their useable life greatly. 

Metals Prone to Stress Corrosion Cracking

Stress corrosion cracking is more common in alloys than pure metals, but can occur in a variety of materials, including:

• Austenitic Stainless Steels & Aluminum Alloys
• Mild Steel
• Copper Alloys  

A seemingly obvious solution is to replace the susceptible metal with a more SCC-resistant alloy.  However, this method involves great cost and extensive time to achieve, and its success rate has proven marginal. 

Ultrasonic Impact Technology on the other hand, quickly and effectively improves surface quality and alleviate tensile stresses in a multitude of vulnerable metals without the need or drawbacks of component replacement.  This has led to its emergence as a preferred option in numerous industries.

Digging Deep to Prevent Stress Corrosion Cracking

Detrimental tensile stresses at or near a metal’s surface bring about the onset of miniscule cracks that propagate and spread to a critical level.  Conventional methods, such as needle peening and cavitation peening were initially utilized to prevent stress corrosion cracking due to their ability to deliver compressive residual stresses into susceptible, fatigued metals.  However, the depth to which tensile stresses are relieved via these methods, are relatively shallow and their application causes a considerable amount of cold working, which actually increases the risk of SCC.

By driving tensile stresses to a depth of 12mm (far beyond the capabilities of conventional methods) and introducing beneficial compressive stresses near the surface, Ultrasonic Impact Treatment drastically reduces the dangers inherent in tensile stresses and combats another component of stress corrosion cracking. 

Preventing Stress Corrosion Cracking on All Levels

Stress corrosion cracking requires the “combination” of a vulnerable metal, tensile stresses, and a corrosive environment.  Therefore, effective stress corrosion cracking treatment requires only 1 of the 3 ingredients be removed.  As Ultrasonic Impact Treatment has been proven to improve the intergranular composition of susceptible metals, remove tensile stresses from the surface, and effectively restore surface quality; it provides lasting protection against the devastating financial, operational and life threatening impact of stress corrosion cracking.