AOPT - Ion Beam Surface Treatment (IBESTTM) Technology
IBESTTM technology, is a thermal process, uses very high energy, rapidly pulsed ion beams to melt the surface of a material to a depth of 5-10 microns. The bulk of the material, acting as a heat sink then cools the thin melted surface layer in less than a microsecond,
The IBEST process modifies and improves existing material surfaces by near-instantaneous melting and cooling of the existing material, not by adding coatings or diffusing chemicals into the surface. This difference enables IBEST to provide benefits that cannot be matched by any other capability.
The short processing time, a few seconds, which is an integral part of the IBEST treatment, makes IBEST technology cost effective compared to other, much slower surface treatment techniques. In marked contrast to many other material surface treatments, IBEST is chemical-free, produces no waste stream, and uses negligible consumable materials.
The result of the fast melting and cooling changes the surface characteristics of steels like H13, 17-4PH, O1 and M2 making them harder, with a very small grain size, resulting in improved corrosion, wear and fatigue properties. While some tool and gear steels have reached a Rockwell hardness of more than HRC 70, other materials like 316 stainless steel and aluminum alloys typically show significant increases in corrosion and wear resistance. Other materials like ceramics and plastics have also shown potential for improvement by IBEST.
Powder Metallurgy Applications
Power metallurgy, and especially a rapidly growing market segment of PM called Metal Injection Molding (MIM), is becoming widely used to fabricate small, complex, high precision parts without the high cost of machining. Improved surface finish and density are important in this industry. IBESTTM has demonstrated that it can smooth and densify Metal Injection Molded (MIM) surfaces and also provide increased hardness in some cases.
Electrical Discharge Machining
Some companies have shown interest in smoothing both mechanical and EDM (Electrical Discharge Machined) machining marks on a die surface. Figure 2a and b show the ability of the IBEST treatment to smooth an H13 EDM surface.
IBEST treatment of M2 material has shown an increase in hardness of more than 50% on the Knoop scale shown in figure 3, representing a Rockwell hardness of more than 70.
The melt region shows the absence of clearly defined carbides evident in the bulk material, having been kept in solid phase solution due to the rapid cooling process. Analysis by transmission electron microscopy revealed 20-nm grain size, a dramatic reduction from the original structure.
Other demonstrated treatment capabilities and benefits include:
- Lifetime Extension of Carbide and High Alloy Steel Tools
Treatment of carbide tools using IBESTTM– has shown improved smoothness, and in customer tests has provided significant lifetime extension of tools cutting aluminum and cast iron. Cutting blades have been made harder and smoother.
- Corrosion and Fatigue Resistance
In tests by a turbine manufacturer, IBEST-processed, uncoated, 17-4PH stainless steel, forged turbine blades showed no corrosion in customer conducted 1000 hour salt spray test. Tests conducted by a QMT vendor/partner using titanium alloy compressor blades demonstrated that IBEST processing significantly increased both fatigue and erosion resistance.
- Healing of Surface Cracks
Tests of IBESTTM-processed gear material for a leading automotive supplier showed that IBESTTM processing can eliminate surface cracks in carburized materials to a depth of approximately 10 microns.
- Surface Preparation for Coatings
IBESTTM has demonstrated its ability to prepare surfaces for subsequent coatings by cleaning, melting, and homogenizing surfaces while removing inclusions, cracks, or other defects that could lead to coating failure. In addition, IBESTTM has shown that it can remove unwanted coatings or surface layers while preserving precise dimensions of the underlying material.
AOPT offers customers access to IBEST treatment for both process development and parts treatment at it’s commercial Surface Treatment Center in Albuquerque New Mexico. As part of its service to customers, AOPT has developed process recipes, including optimized treatment levels, numbers of pulses and other proprietary treatment conditions that provide specific benefits for more than 20 different materials as shown below.
Material Demonstrated Benefit
- All metals creation of fine grain (<150 nm) crystal structure
- 1045 and 1060 carbon steel hardness, smoothness, homogeneity, wear
- 304, 316, stainless steels improved corrosion resistance
- 15-5PH, CRES 320 improved corrosion resistance
- 17-4-PH stainless steel corrosion resistance, hardness, smoothness
- 440A, 440C martensitic steel improved wear, lubricity, and hardness
- 8620 gear steel crack healing, homogenization
- M2 tool steel hardening, smoothing
- M7 and M42 tool steel smoothing, homogenization
- O-1 tool steel hardening, wear resistance
- H13 tool steel hardening, wear resistance
- 80%Fe-20%B smoothing, amorphous structure
- Ti-6-4 smoothing, fatigue and erosion resistance
- Al 2024, 6061 corrosion resistance and wear
- Cemented tungsten carbide smoothing, and wear resistance
- Powder metallurgy parts smoothing, surface sealing, hardening
- Polycarbonate improved adhesion