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Internal Combustion Engines Failure analysis and material control

Evaluating Parts and Materials for Increasing the Temperature and Failure Analysis of Surface-hardened Gears
Pressure of Engines and Exhaust Systems to Improve Fuel Efficiency – Hardness Distribution Evaluation and Fracture Origin Analysis by Carbon Content Mapping –

- Testing Based on a Simulated Internal Engine Environment -
Combustion efficiency is being improved by increasing the temperature and pressure inside the engine. Therefore, it is increasingly important to select or Shafts, bearings, gears, and other automotive mechanical parts subject to high loads are often hardened, such as by high-frequency quenching, nitriding
design materials that are suitable for high temperatures and pressures. In this example, thermal fatigue was evaluated to determine the performance of or carburizing treatments, or coating technologies to improve their wear resistance and durability. Normally, quality is checked by measuring the depth of
engine and exhaust system materials and the internal pressure fatigue was evaluated to assess pipes and other pressure-resistant parts. the hardened layer. However, hardness can vary depending on the part shape and treatment conditions. Consequently, there is an increasing need to
evaluate the hardness distribution. Similarly, hardness distribution evaluation is also being used to evaluate heat and pressure welded joints in more detail
Evaluating Internal Pressure Fatigue than before. Typical hardness tests involve cutting out and testing part of the sample, but there is an increasing need to test the hardness in its unaltered

Pressure amplifier form. Hardness mapping is sometimes used for detailed analysis together with carbon content mapping. An example of a current topic in hardness
mechanism
testing and composition mapping that meets these needs is shown below.
Evaluating Hardness Variations in Automotive Parts
Pressure amplifier
mechanism
Sample Surface

Cross
Electric-Hydraulic Pressurization section
Fatigue Testing System Depressurization Evaluating the Depth of
EHF-U Series Sample the Hardened Layer
mounting port
(JIS G 0559, ISO 3754)
The pressure amplifier is used to apply pressure from inside the sample. Configured with special low-friction alloy bearings, precisely machined plungers, cylinders
specially polished to improve durability, and a manifold, the system repeatedly applies high and forced-vacuum pressures for high-speed accelerated testing (10 Hz).

· 300 MPa internal pressure loads can be applied 2. Multiple samples can be tested at the same time
Mapping the Carbon
Evaluating DLC Coating Stability Mapping the Hardness of a Gear Content of a Gear
– Evaluating the Physical Properties of DLC Coating Layers by Microindentation Tests –

Diamond-like carbon (DLC) coatings are thin, but very hard and can provide high wear resistance and high
lubricity. Consequently, the coatings are often used on engine and fuel injection parts that involve significant
sliding. DLC coatings are applied to target part surfaces by methods such as chemical vapor deposition
(CVD) and sputtering. Though applying a DLC coating to flat surfaces is easy, forming the coating properly
on bumpy surfaces can be difficult in some cases. The following is an example of microindentation tests
using a DUH series ultra micro hardness tester as one means of evaluating whether or not reliable coating
formation can be achieved on parts with complex shape. Dynamic Ultra Micro Hardness Testers
DUH-211 Series
Description
Fully Automatic, from Measuring the Hardened Layer Capable of Mapping the Content
Test Force vs. Depth Graph
The physical properties of DLC coatings applied with different coating conditions were Test Force vs. Depth Graph
40 Depth to Mapping Hardness Fully Automatic of Carbon and Other Components
compared. The results show the hardness and Young's modulus vary depending on the
coating conditions. HMV-G31-FA Series Tester EPMA Series
No2 No1
By performing tests with an indentation depth of about 1/10 the thickness of the coating
layer, the physical properties of only the coating can be evaluated, without influence from
the substrate material. Therefore, microindentation tests are perfect for DLC coatings only a Test Force (mN) · The edge detection function enables the sample shape to be automatically recognized and allows the testing position to
few microns thick, which is commonly used in the automotive industry.
be specified easily. This makes it possible to not only evaluate the depth of the hardened layer but also easily evaluate the
Test Conditions composition via hardness mapping.
Test Mode: Loading-unloading · The functional design provides a large and user-friendly work space, which is especially spacious in the depth direction and
0
Sample Name: DLC coating (1 µm) Depth (µm) 0.5 there is an opening in the center area of the frame. That means the tester can directly test parts that were too big or long
Test Load: 20 mN
Loading Speed: 2.6 mN/sec to test previously.
Holding Time: 5 sec

· Enables physical properties evaluation of only the coating layer.
· Physical properties of DLC coating layers can be evaluated using a quick and simple method.

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