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Additive Manufacturing (AM) provides significant opportunities in aerospace applications, especially for low-volume, highly customizable parts. Besides the flexibility of part design, the approach offers significant potential of reducing product manufacturing complexity and improving in-service performance. This paper discusses an example which is in serial production at Howmet Fastening Systems. The part is a latch used in a hold-down assembly for avionics. The primary driver for the initiative was the need for increased torsional strength within the geometric constraints of the baseline design. Finite Element Analysis was used to redesign one load limiting component to improve overall torsional capability. Design for AM (DFAM) was used to successfully produce the parts without any defects with limited post-processing. Comprehensive testing included component tensile, fatigue, and microstructure characterization along with assembled part testing.

Following the trend in automotive manufacturing, electric cordless tooling platforms are gradually being adopted for aerospace assembly tool systems. This paper introduces a new portable aerospace fastener assembly tool system based on the cordless electric technology platform. These systems are significantly more accurate than traditional pneumatic–based assembly tool systems and offer a range of process monitoring options. Cordless assembly tool systems make the assembly process easier, faster, safer and more accurate. These systems have the ability to provide traceability with time & date stamp for each installed fastener and provide wireless communication to enable process monitoring in real time. A comparison with traditional aerospace tool systems is made, in terms of historical evolution and working performance. Lessons learned from automotive applications are brought to aerospace industry. Key benefits include better ergonomics, improved accessibility, productivity and cost.

The installation of aerospace fasteners with pneumatic or cordless tools generally requires specialized systems which are dedicated to the fastener hex size and torque, often requiring laborious disassembly for a configuration change. This paper presents a quick change system that can be used together with a large variety of tooling configurations and provides instant socket exchange without requiring wrenching or disassembly. A comparison with traditional socket system is made, highlighting the characteristics and benefits of this new technology in terms of ergonomics, productivity and cost.

Since 2005, Alcoa Fastening Systems (AFS) and Lockheed Martin have been partnering to identify a Cadmium (Cd) plating replacement for threaded fasteners. Previously reported Phase I, II and III studies resulted in alternative coatings that indicated promise as suitable plating materials. Phase IV and V studies continued the program by testing two different fasteners (NAS1580 and NAS4452) manufactured in AFS facilities. Testing included plating material characterization such as coating thickness, torque-tension relationships, locking and breakaway torque measurements, salt spray (fog) corrosion, stress corrosion, and push-in and interference properties. Additionally, mechanical properties of the plated fasteners were tested (tensile, double shear, durability, and fatigue). Candidates included two electroplated zinc-nickel coating systems (Zn-Ni and Zn-Ni2) and an electrodeposited aluminum coating (AI).

Cadmium electroplating is coming under increasing pressure due to both environmental and worker safety issues. Since 2005, Alcoa Fastening Systems (AFS) and Lockheed Martin have been conducting a collaborative research program to identify the most appropriate fastener coating materials for a Cadmium (Cd) plating replacement. Four candidate coatings were selected for the initial Phase I evaluation: electroless nickel (EN), electroless nickel composite (EN-PTFE), electrodeposited surface mineralization based zinc-nickel (Zn-Ni), and electroplated aluminum (Al). The Phase I testing results indicated that the Zn-Ni and Al coatings were the best of the four candidates for Cd replacement. However, it is hard to conduct direct comparisons with different coating thicknesses, surface treatments, and lubrication among various Cd alternatives. Thus, further evaluation with more careful control of these parameters would be necessary.

A new type of temporary fastener fulfills the requirement of reduced specific loads applied to composite structures. With that the danger of delamination especially at sloped surfaces is under control and limited. It is also insensitive to contamination and provides reduced maintenance of the clamping means. For disassembly a controlled screwing process guaranties that structure and panel will not be damaged.

Light weight aerospace fastening collars were manufactured from 2099 alloy which is a new generation Al-Li alloy developed by Alcoa. The collars studied in this work are threaded self-locking collars with controlled torque-off feature and are to be used in a fastener assembly with a treated pin. The mechanical properties of 2099 collars were measured and compared to the ones made of incumbent alloys such as 7075 and 2024. It was found that the 2099 collars were 16% lighter but provided the equivalent mechanical properties. In addition, the corrosion characteristics of the 2099 collars were studied using the salt spray and alternate immersion test methods. It was observed that 2099 collars exhibited an improved corrosion performance as compared to the base line 7075 collars. This paper presents the results obtained from the mechanical and corrosion testing of the Al-Li collars along with the weight saving potentials of the new product.