Nov_Dec_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | N O V E M B E R / D E C E M B E R 2 0 1 7 2 3 M aking products with consistently high quality requires well trained people, effective process control, and the razor sharp eyes of advanced test and measurement equipment. Trusted suppliers, of course, are also necessary, but the goods and materials they pro- vide must still be tested to make certain all specs are met. In-process tests, in a similar way, are necessary to verify each manufacturing step while also generat- ing valuable data for continuous process improvement. Advanced Materials & Pro- cesses spoke with Gordon Styles, presi- dent of Star Rapid Manufacturing Ltd., to learn more about what goes into materi- als verification processes. and optical emission spectroscopy, also known as spark testing. And for plas- tics, we began to do RoHS testing and started using Raman spectroscopy. No matter where you are, it is essential to verify all materials that come through the door. Although the practice of test- ing materials is not common through- out China, it should be. AM&P: How often do you come across fraudulent materials and have these occurrences increased over the years? GS: I was shocked by the discovery of fraudulent materials when we began operations in China because I ran a rap- id prototyping, low-volume factory in the UK from 1983 to 2000 and never felt a need to test metals and plastics. If the material was stamped “304 stainless steel” or “30% glass filled nylon,” there was a high probability that is what it was. When we first started testing in China, we found that about two-thirds of the stainless and one-third of the alu- minum was nonconforming or fake. AM&P: What’s the difference between nonconforming and fake? GS: Nonconforming material is a poorly made material that lies outside of internationally agreed upon toler- ances. Maybe there is too little chromi- um or too much nickel, but the material is still broadly 304 stainless, for exam- ple. Fake material is when the supplier delivers a completely different metal- lurgy, often knowingly and deliberate- ly. The classic fake for 304 stainless is 201, a nonmagnetic stainless steel that looks just like 304. The problem with 201—aside from the fact that it is not easily detectable, i.e., with a magnet, like other types of stainless—is that it rusts quite readily under normal at- mospheric conditions and even more so in high humidity and outdoor envi- ronments. The key difference between 304 and 201 is that the 300 series is based on chromium-nickel metallur- gy, whereas the 200 series is based on chromium-manganese. Since we purchased our testing equipment, we have seen a large drop- off in the amount of fake and noncon- forming materials we have to reject. The ratio is now down to around 10%, TECHNICAL SPOTLIGHT TRUST BUT VERIFY With today’s sophisticated measurement technology and testing equipment, manufacturers need never be in doubt over the quality of their starting materials and any property changes that occur in process. AM&P: Is the testing of incoming materials a common practice for rapid prototyping and low-volume manufacturing companies? GS: Over 10 years ago, when I first moved to China to explore the idea of starting a factory, we found that many suppliers within the country were pro- viding fake materials. As a result, we invested hundreds of thousands of dollars on test equipment and began running a battery of tests on incoming metals, including x-ray fluorescence Laser scanning inspection tool for verifying part geometries. Modern quality control lab for testing parts andmaterials.