Titanium CRMs Help Drive Novel Materials Needs
Alpha Resources offers an unparalleled selection of titanium Certified Reference Materials to support vital industries including aerospace, automotive, electrics, medical, power, oil, and gas
Kent Dyer is Alpha Resources’ chief chemist and has been with the company for more than 25 years. He is an engaged ASTM member with three active committee affiliations (E01—Metals & Ores, D05—Coal & Coke, D02- Petroleum) and has served as technical contact on several test methods.
Q: What are certified reference materials (CRMs)?
A: Certified reference materials (CRMs) are carefully crafted materials that have been characterized by accurate and precise procedures for specified properties. The corresponding reference material certificates state the property values and concentration uncertainties and confirm the necessary procedures have been performed to ensure accuracy, precision, validity, and traceability. CRMs ensure the quality of products, validate analytical methods, and assess the accuracy of experimental results among laboratories.
Q: What is the specialty behind Alpha Resources' Titanium CRMs?
A: Typically, during analysis you “bracket down” (comparing elemental concentrations realistically, for example, comparing a CRM of elemental concentrations 1000-5000 ug/g to another of 5-10 ug/g is not feasible) with CRMs on known values; sometimes starting with a low concentration value to calibrate a known floor of the test. Having a wide range of CRM options for a given metal, such as titanium, ensures that labs testing titanium can precisely analyze their materials for multiple factors. Accurate data is the key. For Alpha, robust statistical techniques are used to create a value that is not only repeatable, where the results procured are consistent over multiple experiments within one lab, but also very reproducible, where the results are replicable over multiple experiments in other labs.
Labs can trust Alpha’s CRMs to evaluate the hydrogen/oxygen/nitrogen content of various titanium alloys to ensure they meet specifications. Titanium and its alloys, including Ti 6Al-4V ELI, are prone to hydrogen embrittlement or reduced ductility in the metal due to absorbed hydrogen. As titanium gets machined, stamped, or goes through chemical processes it can gain hydrogen and thus cause the titanium to become brittle and break. If you consider the common applications of titanium—aerospace and medical use—metal fatigue from embrittlement could cause breakage, with catastrophic results.
It is important to minimize hydrogen pickup during processing, particularly during heat treatment and acid pickling. Specifications for Ti 6Al-4V ELI (ASTM F 136) mill products typically specify a maximum hydrogen limit of 120 ppm.
Oxygen can be difficult to quantitate in metals unless combustion analysis is used. Oxygen is a predominant interstitial impurity, widely adopted in titanium-based alloys to enable a potent strengthening effect for diverse applications. Therefore, the determination of the oxygen content in titanium alloys has important practical requirements and significance. For titanium grades, oxygen is usually specified to around 0.2 percent to increase strength. Nitrogen is an alloying element in titanium, where its presence affects weldability. Depending on the specific grade, the nitrogen content is usually kept between 0.02 percent and 0.05 percent.
Alpha also offers titanium CRMs with carbon values which can be useful for the calibration and validation of induction combustion, infrared (carbon), and thermal conductivity (hydrogen) analyzers used in various ASTM methods. Alpha also took on ISO 17025 and then ISO 17034 certification to ensure customers would have quality CRM products to meet their demands and confidence in product integrity.
Q: What applications or products are Alpha Resources' titanium CRMs targeting?
A: Alpha has been expanding titanium CRM options for industrial applications since 1996 when we offered six titanium CRMs and one zirconium CRM with a limited range. Since then, we’ve created CRMs to meet market demand as the use of titanium in aerospace and medical applications increased.
This commitment to the needs of the titanium industry has made Alpha the supplier of choice and resulted in collaborations for specific applications. Through customer feedback and industry demand, Alpha understands additional needs for titanium CRMs including needs for carbon values and smaller sample sizes. Most recently, we had a customer request for a very low oxygen value in a titanium CRM. Alpha always welcomes collaboration with our customers and the industry.
This need for options and specificity of values in titanium is why Alpha offers more titanium CRM choices than most OEMs do.
Q: How many Titanium CRMs are there in Alpha Resources' product line?
A: We currently offer 20 titanium CRMs—11 variations of O/N/H in 0.1g pins and we offer 9 CRMs in the 0.25g size appropriate for C/H. Since zirconium is also tested and is part of refractory alloys like titanium, Alpha Resources also offers 2 CRMS of zirconium type as well.
Q: Is there a difference between analytical standards and certified reference materials (CRMs)?
A: A basic analytical standard is anything that can be used as a comparative reference to differentiate between materials such as iron or copper. It satisfies basic chemical needs but provides very little in terms of quantitation, precision, or uncertainty.
For example, a geologist identifying different types of rocks using a handheld X-ray analyzer would use a non-certified reference material to identify the type of rock. It may not be a quantitative analysis but will identify the different compositions as the geologist walks around an area. The same process might be used in a scrapyard to identify the difference between iron, aluminum, and other metals.
A CRM offers more and provides an in-depth characterization of the material by providing one or more accepted test methods and measurement to a 95% confidence limit, with test traceability and/or traceability to a National Metrology Institute (NMI), such as NIST or other ISO 17034 accredited references. Then, the material is certified by an accredited reference material producer providing additional precision and trace elemental concentrations that may be important.
Q: How do CRMs differ between original equipment manufacturers (OEMs) and aftermarket suppliers?
A: OEMs who manufacture their own CRMs use only their analyzers. Most other aftermarket suppliers use third-party testing labs
Instead of relying on a single analyzer or analyzer brand, Alpha (and other similar aftermarket suppliers) use multiple analyzers from various OEMs to avoid any potential manufacturer bias. Alpha invests heavily in having a variety of OEM instrumentation and generations of equipment for a broader data set.
After identifying subtle differences between CRMs provided by Metrology Institutes such as NIST (USA), BAM (Germany), JSS (Japan), and others, Alpha Resources’ technical team has developed a multinational reference approach to traceability. This provides customers with more robust CRMs applicable for international comparisons.
Using reference materials from various National Metrology Institutes, Alpha’s validation services better serve labs with international needs and can offer not just a standard or one sigma deviation (68 percent level of confidence), but the expanded or two sigma deviation (95 percent level of confidence) for uncertainty.
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Founded in 1978, Alpha Resources, LLC is a global leader in the creation of certified reference materials and the manufacture and distribution of consumables for use in atomic spectroscopy analysis and is ISO17034, ISO17025, and ISO9001:2015 certified. Alpha Resources has a long history of servicing critical industries both domestically and internationally. While Alpha Resources offers both organic and inorganic standards, our inorganic standards provide one of the broadest ranges available in the marketplace.
