Grooved Stent Coating Failure Using Nano Scratch Testing

Drug–eluting stent is a novel approach in stent technology. It possesses a biodegradable and biocompatible polymer coating that releases medicine slowly and continuously at the local artery to inhibit intimal thickening and prevent the artery from being blocked again. One of the major concerns is the delamination of the polymer coating that carries the drug-eluting layer from the metal stent substrate. In order to improve the adhesion of this coating to the substrate, the stent is designed in different shapes. Specifically in this study, the polymer coating locates at the bottom of the groove on the mesh wire, which brings enormous challenge to the adhesion measurement. A reliable technique is in need to quantitatively measure the interfacial strength between the polymer coating and the metal substrate. The special shape and the small diameter of the stent mesh (comparable to a human hair) require ultrafine X-Y lateral accuracy to locate the test position and proper control and measurement of the load and depth during the test.

Grooved Stent Coating Failure Using Nano Scratch Testing

In-line Inspection Game Changer

Using in-line inspection (POINT or LINE SENSORS) Nanovea’s unique in-line software package can measure and analyze “live” roughness and texture parameters meeting standards for up to 8 points sensors or up to 4 line sensors. The software has many features including pass and fail criteria specific to each sensor or average of all sensors. Acquisition rates of more than 1,300,000 points per seconds. This is ideal for any film/paper sheet measurements and other in-line applications. Nanovea provides integration support including specific mounting structure.

Coating Inspection of TIN by Scratch Testing

Coating inspection of residual stress in protective PVD/CVD coatings plays a critical role in the performance and mechanical integrity of the coated component. The residual stress derives from several major sources, including growth stress, thermal gradients, geometric constraints and service stresses. The thermal expansion mismatch between the coating and the substrate created during coating deposition at elevated temperatures leads to high thermal residual stress. Moreover, the TiN coated tools are often used under very high concentrated stresses, e.g. drill bits and bearings. It is critical to develop a reliable quality control process to quantitatively inspect the cohesive and adhesive strength of the protective functional coatings.

Coating Inspection of TIN by Scratch Testing

Tribology Inspection of Titanium Nitride Coatings By Tribometer

Wear of the tools in service creates loss of dimensions and functionality of the tools. It has significant influence on the tool life, as well as the surface integrity and dimension accuracy of the finished products. The tribo-mechanical properties of the protective ceramic coatings can substantially enhance the service performance and lifespan of the machine tools. Reliable and accurate tribology inspection of such protective coatings becomes vital to ensure quality performance of the tools.

Inspection of Titanium Nitride Coatings By Tribometer

Roughness Mapping Inspection Using 3D Profilometry

Surface defects of products derive from materials processing and product manufacturing. In-line surface quality inspection ensures the tightest quality control of the end products. The Nanovea 3D Non-Contact Profilometers utilize chromatic confocal technology with unique capability to determine roughness mapping of a sample without contact. The line sensor enables scanning the 3D profile of a large surface at a high speed. The roughness threshold calculated real-time by the analysis software serves as a fast and reliable pass/fail tool.

Roughness Mapping Inspection Using 3D Profilometry

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The AIAA Science and Technology Forum and Exposition (AIAA SciTech Forum) has continued to grow in each succeeding year, drawing participants from around the globe. Plenary and Forum 360 participants tackled the most pressing issues impacting the future of aerospace, while the technical program presented innovative research and technologies that offer solutions. Learn More

Block on Ring Tribometer Option

Block on Ring test is a widely used technique that evaluates the sliding wear behaviors of materials in different simulated conditions, allows reliable ranking of material couples for specific tribological applications. Sliding wear often involves complex wear mechanisms taking place at the contact surface, such as adhesion wear, two-body abrasion, three-body abrasion and fatigue wear. The wear behavior of materials is significantly influenced by the work environment, such as normal loading, speed, corrosion and lubrication. A versatile tribometer that can simulate the different realistic work conditions will be ideal for wear evaluation.

Compression Set Measurement With 3D Profilometry

Compression set measurement of rubbers progressively recover their shape after the compressive stress is removed. Accurate in situ monitoring of the shape evolution during the compression set period can provide important insight into the mechanism of material recovery. Moreover, real-time monitoring of surface morphologies is very useful in various materials applications, such as paint drying and 3D printing. The Nanovea 3D Non-Contact Profilometers measure the surface morphology of materials without touching the sample, avoiding introducing additional scratches or shape alteration which may be caused by contact technologies such as sliding stylus.

Stress Relaxation Measurement With Nanoindentation

As per ASTM E 328, Standard Test Methods for Stress Relaxation for Materials and Structures, external force is initially applied on the material or structure to reach a constant constraint, and then the change in the external force necessary to maintain this constraint is measured as a function of time. The major difficulty in the stress relaxation test is maintaining the constant constraint. The nanoindentation module of Nanovea Mechanical Tester accurately measures the stress relaxation by applying the close loop control of the load with ultra-sensitive load cell and piezo. The piezo reacts real-time to keep the constraint constant while the change in load is measured and recorded by the high precision load cell. This measurement can be performed on virtually all types of materials without the stringent requirement of sample dimension. Multiple stress relaxation tests can be performed on the same flat sample to ensure the test repeatability, which substantially reduces the cost on sample manufacturing and machining.

Honeycomb Panel Finish, Tribology and Mechanical Properties

Honeycomb panel analysis including mechanical properties using microindentation, surface finish using 3D profilometery and wear resistance using Tribometer.




App Notes