Scientists at the National Polytechnic Institute (IPN) are analyzing the behavior of aluminum alloys subjected to repeated loads to determine their service life and prevent premature failures in components used in various industries.

In everyday life, many of the structures and devices we use rely on materials that must withstand constant mechanical loads over long periods of time.

Bridges, vehicles, industrial machinery, and even trains are exposed to repetitive loads that, over time, can cause progressive deterioration. Understanding how this process occurs is essential to preventing structural failures and ensuring safety.

This is the objective of an ongoing research line of research being conducted at the Center for Research and Technological Innovation (Ciitec), where scientists are studying the phenomenon known as material fatigue, particularly in aluminum alloys used in various industrial sectors.

The project is led by the center’s director, Ricardo Rafael Ambriz Rojas, whose work focuses on the mechanical behavior and joining of metallic materials, as well as their performance when integrated into structures or components subjected to demanding conditions.

“The study of fatigue is an area of research we pursue on an ongoing basis. My background involves the study of metal alloys, particularly aluminum alloys and their welded joints”, Dr. Ambriz explained in an interview with the Conversus News Agency (AIC).

Aluminum alloys are widely used in various industries due to their properties as lightweight, corrosion-resistant materials with a favorable strength-to-weight ratio. These characteristics make them an ideal choice for applications in the automotive, aerospace, and rail sectors, among others.

However, as with many materials, their performance can be affected when subjected to cyclic loads—that is, stresses that repeat continuously throughout their service life. Over time, this process can generate small internal cracks that eventually lead to fracture.

According to Ricardo Rafael, understanding this phenomenon is key to preventing accidents and structural failures.

“The goal is to determine the safe conditions under which these materials can be used, ensuring they have an adequate service life and avoiding issues related to risks to people”, noted Ambriz Rojas.

WHEN MATERIALS “BECOME FATIGUED”

The term “material fatigue” may seem abstract, but it can be explained with a simple analogy.

“Fatigue can be understood as cumulative damage that occurs when a material is subjected to repeated loads. It’s similar to how people feel tired after sustained exertion; materials also accumulate that damage and can eventually fail”, explained the polytechnic specialist.

This process can take years to manifest and often occurs silently. At first glance, a metal part may appear intact, but inside there may be microcracks that gradually grow until they cause a sudden fracture.

Therefore, knowing how long a material can withstand certain conditions is essential information for the design of safe components and structures.

TESTS THAT SIMULATE REAL-WORLD CONDITIONS

To analyze how materials behave, researchers conduct various laboratory tests. Some of these are standard in industrial quality control, while others require specialized equipment.

Among the best-known tests are hardness tests, which measure a material’s resistance to penetration by another object; however, the study of fatigue involves more complex evaluations.

“We use servo-hydraulic equipment that allows us to subject materials to controlled loading cycles. This way, we can observe how they behave over time and determine when damage begins to appear”, explained the researcher.

This equipment replicates conditions similar to those a part would face under real operating conditions, such as the vibrations or repetitive stresses experienced by an automotive component or a metal structure.

In addition, the specialists combine experimental results with computational tools and mathematical models, which allows for a more precise analysis of the deformation and deterioration processes of materials.

“There are always scientific questions to be answered. The mechanical behavior and joining of materials is a very broad and multidisciplinary field”, said the doctor.

ADVANCED ALLOYS AND REMAINING SERVICE LIFE

Currently, the center’s research team is focusing on the study of aluminum alloys hardened through precipitation hardening treatment, a process also known as artificial aging.

This treatment modifies the material’s internal microstructure to improve its mechanical strength. However, it can also affect its fatigue behavior.

The scientists first analyze the material’s initial properties and then evaluate how they change when joints are made by welding or when the parts have been subjected to repeated loading cycles.

One of the key aspects of the study is determining the remaining service life of the materials—that is, how long they can continue to function after being subjected to certain conditions of use.

“In the laboratory, we determine the remaining service life of these materials have left after they have been subjected to cyclic loading. This allows us to estimate how long they can continue to be used safely”, he said.

This information is particularly useful in sectors where metal components must remain in operation for long periods, such as the transportation industry or civil infrastructure.

APPLICATIONS IN MULTIPLE INDUSTRIES

Although the study focuses on aluminum alloys, the research findings have broader implications.

The knowledge gained can be applied in various fields, from vehicle manufacturing to the construction of metal structures.

“The applications are very diverse. Understanding the properties of materials under fatigue conditions allows us to determine with greater certainty the service life of components”, he stated.

For example, in the automotive industry, the metal components of vehicles are subjected to constant vibrations and repetitive stresses during operation. A precise understanding of their behavior can help improve their design and increase their durability.

In the aerospace industry, where the weight and strength of materials are critical factors, aluminum and its alloys play a fundamental role. Determining their fatigue performance is key to ensuring aircraft safety.

The study is also relevant to the civil infrastructure sector, where materials such as steel and aluminum are used in the construction of bridges, buildings, and other structures that must withstand loads for decades.

TOWARD NEW TECHNOLOGICAL SOLUTIONS

In addition to analyzing material behavior, the team at the polytechnic center is working on developing techniques to extend the service life of damaged components.

According to the researcher, some of these methodologies are currently undergoing the patent application process.

These techniques aim to intervene in materials that already have cracks or damage to halt their progression and extend the service life of the component. Such solutions could offer significant benefits to the industry, as they would reduce maintenance and replacement costs while improving structural safety.

RESEARCH AND TRAINING OF SPECIALISTS

The work carried out here contributes not only to technological development but also to the training of specialized professionals.

The center offers master’s and doctoral programs in Advanced Technology, where students participate in research projects and gain experience in specialized laboratories.

For the official, this training effort is one of the pillars of academic work. “These projects also allow young people to gain training and subsequently enter the workforce”, he noted.

Through partnerships with companies and government agencies, the projects developed at Ciitec also seek to address specific needs of the productive sector.