Additive Manufacturing for Crack Repair Applications in Metals

Additive manufacturing (AM) builds intricate parts from 3D CAD model data in successive layers. AM offers several advantages and has become a preferred freeform fabrication, processing, manufacturing, maintenance, and repair technique for metals, thermoplastics, ceramics, and composites. When using laser, it bears several names, which include laser additive manufacturing, laser additive technology, laser metal deposition, laser engineered net shape, direct metal deposition, and laser solid forming. These technologies use a laser beam to locally melt the powder or wire and the substrate that fuse upon solidification. AM is mainly applied in the aerospace and biomedical industries. Titanium (Ti) alloys offer very attractive properties much needed in these industries. This chapter explores AM applications for crack repairs in Ti alloys. Metal cracking industrial challenges, crack detection and repair methods, challenges, and milestones for AM repair of cracks in Ti alloys are also discussed.

Designing Thin 2.5D Parts Optimized for Fused Deposition Modeling

This chapter builds new knowledge for design engineers adopting fused deposition modeling (FDM) technology as an end manufacturing process, rather than simply as a prototyping process. Based on research into 2.5D printing and its use in real-world additive manufacturing situations, a study featuring 111 test pieces across the range of 0.4-4.0mm in thickness were analyzed in increments of 0.1mm to understand how these attributes affect the quality and print time of the parts and isolate specific dimensions which are optimized for the FDM process. The results revealed optimized zones where the outer wall, inner wall/s, and/or infill are produced as continuous extrusions significantly faster to print than thicknesses falling outside of optimized zones. As a result, a quick reference graph and several equations are presented based on fundamental FDM principles, allowing design engineers to implement optimized wall dimensions in computer-aided design (CAD) rather than leaving print optimization to technicians and manufacturers in the final process parameters.

Determination of Optimum Process Parameter Values in Additive Manufacturing for Impact Resistance

3D printing as a manufacturing method is gaining more popularity since 3D printing machines are becoming easily accessible. Especially in a prototyping process of a machine, they can be used, and complex parts with high quality surface finish can be manufactured in a timely manner. However, there is a need to study the effects of different manufacturing parameters on the materials properties of the finished parts. Specifically, this chapter explains the effects of six different process parameters on the impact resistance. In particular, print temperature, print speed, infill ratio, infill pattern, layer height, and print orientation parameters were studied, and their effects on impact resistance were measured experimentally. Moreover, the optimum values of the process parameters for impact resistance were found. This chapter provides an important guideline for 3D manufacturing in terms of impact resistance of the printed parts. Furthermore, by using this methodology the effects of different 3D printing process parameters on the other material, properties can be determined.

Parameters Optimization of FDM for the Quality of Prototypes Using an Integrated MCDM Approach

Fused deposition modeling (FDM) is one of the emerging rapid prototyping (RP) processes in additive manufacturing. FDM fabricates the quality prototype directly from the CAD data and is dependent on the various process parameters, hence optimization is essential. In the present chapter, process parameters of FDM process are analyzed using an integrated MCDM approach. The integrated MCDM approach consists of modified fuzzy with ANP methods. Experimentation is performed considering three process parameters, namely layer height, shell thickness, and fill density, and corresponding response parameters, namely ultimate tensile strength, dimensional accuracy, and manufacturing time are determined. Thereafter, optimization of FDM process parameters is done using proposed method. The result shows that exp.no-4 yields the optimal process parameters for FDM and provides optimal parameters as layer height of 0.08 mm, shell thickness of 2.0 mm and fill density of 100%. Also, optimal setting provides higher ultimate TS, good DA, and lesser MT as well as improving the performance and efficiency of FDM.

Additive Manufacturing

Three-dimensional printing has evolved into an advanced laser additive manufacturing (AM) process with capacity of directly producing parts through CAD model. AM technology parts are fabricated through layer by layer build-up additive process. AM technology cuts down material wastage, reduces buy-to-fly ratio, fabricates complex parts, and repairs damaged old functional components. Titanium aluminide alloys fall under the group of intermetallic compounds known for high temperature applications and display of superior physical and mechanical properties, which made them most sort after in the aeronautic, energy, and automobile industries. Laser metal deposition is an AM process used in the repair and fabrication of solid components but sometimes associated with thermal induced stresses which sometimes led to cracks in deposited parts. This chapter looks at some AM processes with more emphasis on laser metal deposition technique, effect of LMD processing parameters, and preheating of substrate on the physical, microstructural, and mechanical properties of components produced through AM process.

Additive Manufacturing

Additive manufacturing (AM) is the most advanced recently trending manufacturing technique that employs 3D printers to create 3D objects by layer upon layer fabrication from the base to the top. The required trajectory of the fabricating tool to create the layer can be well programmed by CAD software available in the market. The 3D CAD model in the computer can be manipulated and customized for different design needs of the product. These manipulations in model and quick fabrication process make the system a flexible and an effective one. This chapter discusses the AM application in educational system by describing the individual AM processes, their limitations, advantages, feasibility in general conditions, and planning for future generations to get accustomed to this technology from the early education in schools to the specialized education in universities. The technology enables students to convert 2D objects into 3D on the CAD software and feel them physically by 3D printing. AM also enables teachers to demonstrate their ideas easily to students.

Importance of 3D Printing Technology in Medical Fields

Three-dimensional or 3D printing technology is a growing interest in medical fields like tissue engineering, dental, drug delivery, prosthetics, and implants. It is also known as the additive manufacturing (AM) process because the objects are done by extruding or depositing the material layer by layer, and the material may be like biomaterials, plastics, living cells, or powder ceramics. Specially in the medical field, this new technology has importance rewards in contrast with conventional technologies, such as the capability to fabricate patient-explicit difficult components, desire scaffolds for tissue engineering, and proper material consumption. In this chapter, different types of additive manufacturing (AM) techniques are described that are applied in the medical field, especially in community health and precision medicine.

Optimization of Additive Manufacturing for Layer Sticking and Dimensional Accuracy

When the 3D printing process is considered, there are also other parameters, such as nozzle size, flow rate of material, print-speed, print-bed temperature, cooling rate, and pattern of printing. There are also dependencies that will be addressed in between these parameters; for example, if the printing temperature is increased, it is not clear if the viscosity of the material will increase or decrease. This chapter aims to explain the effect of printing temperature on layer sticking while dimensional accuracy is achieved. Theoretical modelling and experimental testing will be performed to prove the relationship. This type of formulation can be later adapted into a slicer program, so that the program automatically selects some of the printing parameters to achieve desired dimensional accuracy and layer sticking.

Design of Prosthetic Heart Valve and Application of Additive Manufacturing

Heart valve prostheses are well known and can be classified in two major types or categories: biological and mechanical. Biological valves (i.e., Homografts and Heterografts) make use of animal tissue as the valving mechanism whereas mechanical valves make use of balls, disks, and other mechanical valving mechanism. Mechanical valves carry considerable risk and require lifelong medication. The design of these valves is usually done on a “one size fits all” basis, with only the diameter changing depending on the model being produced. The author seeks to present an application of additive manufacturing in the design process for mechanical valves. This is expected to provide patients with customized prostheses to match their physiology and reduce the risk associated with the implantation.

Recent Advancement in Additive Manufacturing

Additive manufacturing (AM) is acquiring attention in the field of manufacturing. The technique facilitates building of parts through the addition of materials using a computerized three-dimensional solid model. However, the process does not require any coolants, cutting tools, or other resources that are used in conventional manufacturing. The numerous advantages over conventional manufacturing have created interest towards the applications of additive manufacturing in the field of engineering. The governing fundamental principles of additive manufacturing offer a wide spectrum of advantages which includes design, geometric flexibility, near-net-shape capabilities, and fabrication using various materials, reducing the cycle time for manufacturing and overall savings in both energy and costs. The chapter provides a step-by-step procedure for generation of a component through 3D printing and a brief discussion on advanced AM techniques. These can produce high-quality products at high speed and can be used as industrial manufacturing techniques.