Additive manufacturing enables the production of customized and complex parts. These two aspects are attractive for the aerospace and medical sectors. In these critical sectors, however, governed by strict safety requirements, the quality of the parts is of paramount importance, and the technology has advanced at a much faster pace than regulations and quality controls. The reliability of the parts must be guaranteed, and hence quality control is needed. Considering the complexity of additively manufactured part shapes, the inspection methods need to be nondestructive, three-dimensional, and volumetric. X-ray computed tomography is presently the most appropriate method, but the relatively high cost and testing duration make routine inspection difficult. Thus, alternative nondestructive volumetric methods are required. In this paper, four alternative methods utilizing acoustic waves (resonant acoustic method, process compensated resonance testing) and ultrasonic waves (conventional ultrasonic testing, phased array ultrasonic testing combined with total focusing method) are investigated and compared with X-ray computed tomography using synchrotron radiation.

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IADC Members *SPE Member Abstract The introduction of FDS+ bits in 1991 has significantly improved the performance of these types of soft formation milled tooth rock bits. Average bit life has been increased significantly, resulting in a substantial reduction in drilling cost. Tooth grading of the FDS+ bits also is much better than that of conventional milled tooth bits. In certain locations, the new FDS+ bits have approached the life of some soft formation tungsten carbide insert (TCI) rock bits. This paper documents the successful development and application of these improved milled tooth bits, and briefly describes the following:Design innovation of the newly-patented radiused crest tooth.Development of improved hardfacing materials and process.Field-test results. Introduction Milled tooth bits are commonly used in drilling soft to very soft formations. The milled teeth are hardfaced with wear-resistant material comprised of tungsten carbide particles dispersed in a steel matrix. The performance of the hardfaced tooth depends on the wear-resistance and toughness of the hardfacing material used and the bonding between the steel tooth and the hardfacing. In early 1988, a patented hardfacing material, Grade 70C, was introduced to the milled tooth rock bit market (Reference 1). As a result, bit performance, bit life and the penetration rate of milled tooth bits were increased and drilling costs were reduced significantly. A performance standard was established in the drilling industry. Stiff competition contributed further to an even higher level of overall performance of milled tooth bits, which was very beneficial to the drilling industry. The Grade 70C hardfacing material received a Meritorious Award for Engineering Innovation in 1989 from Petroleum Engineering magazine. In late 1990, Smith Intermational's marketing/product management group identified a need for "product differentiation" and for further improvement of milled tooth bit performance. A quality planning project was initiated, with its objective to improve the life and dull condition of milled tooth bits, The resulting cross- functional team was comprised of individuals from the material engineering, design engineering, process engineering and manufacturing groups. Utilizing the quality planning process, the following product features were selected for evaluation:Hardfacing material.Bit/tooth design - tooth shape, tooth spacing, etc.Processing and consistency - weldability, rework rate, porosity, etc. P. 605^