Weibull Distribution of Selective Laser Melted AlSi10Mg Parts for Compression Testing

Selective laser melting (SLM) is an additive manufacturing process to fabricate three-dimensional structures by fusing powder particles using a computer-guided laser source. The SLM process can produce lightweight bespoke designs, having high strength comparable to conventional components. However, the developed surface texture and some of the mechanical properties are still sub-standard compared to the conventional components. The process uncertainty can produce inconsistency in parts’ properties, even those prepared concurrently, affecting SLM parts' repeatability and quality. Therefore, designing applications based on the most probable outcome of the desired properties can embrace process uncertainty. Weibull distribution is a statistical-based probability distribution method that measures the likelihood of the values’ occurrence of any random variable falling in a specific set of values. In this study, the Weibull distribution measured the relative likelihood (90% probability) of the compressive yield, and ultimate strength of the SLM prepared AlSi10Mg samples in a given 22 random sample size. The results showed that the compressive yield and ultimate strength fall between 321 MPa to 382 MPa and 665 MPa to 883 MPa

Estimation of the Compression Strength and Surface Roughness of the As-Built SLS Components Using Weibull Distribution

Selective laser sintering (SLS) is a process of fabrication of three-dimensional structures by fusing powder particles using a guided laser source. The uncertainty in the mechanical properties of the SLS parts fabricated at the same time and with the same process parameters can affect the repeatability of the SLS process. A vast difference in the mechanical properties of the concurrently processed parts can lower the production quality of the batch. Therefore, the parameters are required to be design based on the most probable outcome of the desired properties. Weibull distribution is one such statistical-based probability distribution method to measure the likelihood of the occurrence of a value of any random variable falling within a particular range of values. Here, the Weibull distribution was used to measure the relative likelihood (90% probability) of the surface roughness and the compressive strength values of the SLS-built polyamide PA2200 components in the given sample space that was obtained from 20 random samples. The results show that the variance in the surface roughness (scan and built plane) and the compressive strength values were in the range of 6–7 µm and around 10 MPa, respectively. Moreover, the surface roughness of the two orthogonal planes with 90% reliability was measured at 14.81 µm (scan plane) and 12.15 µm (built plane). Similarly, the yield strength and the compressive strength with 90% reliability were found 25.87 MPa and 62.64 MPa, respectively

Unmanned Aerial Vehicle Production with Additive Manufacturing

In this study, unmanned aerial vehicle (UAV) design, analysis and production was made using selective laser sintering (SLS) system. Four different aircraft bodies were designed in the interdisciplinary project, one of the models was selected by comparing the computational fluid dynamics (CFD) analysis results. According to the numerical study, the model 4 design was found to be the most suitable among the tested models, then the design was produced with the SLS system. Finally, the actual flight test was carried out in three different weather conditions, and the results are presented here

Double Stud Cargo Fitting Research, Alternative Cargo Clip Design and Analysis

In air transportation, fixing the cargo inside the aircraft is important in terms of both flight safety and operational process. Positioning and fixing of the cargo to the aircraft within a short period of time without any risk in terms of flight safety is carried out with the use of some apparatus and subsystems within the pre-determined rules. This fixation is carried out by covering the cargo loaded onto aluminium pallets. The connection of the net on the pallet is provided by metal apparatuses known as clip (Figure 1). These apparatuses are also referred to in the aerospace industry as cargo fitting, double stud cargo fitting. In this study, the design development process of these clips in the history of aviation design, the alternative clip design work we have done and the comparative analysis of this design will be discussed. Firstly, we will address our work on cargo clip in parallel with the historical development process. In this context, different systems and apparatus design studies from the 1950s until the present day will be examined in order to load and stabilize the cargo. In our review, the design development process of cargo clip, the formation of the standard product, with the patent images of the period will be detailed. In this patent review, cargo loading system designs for cargo aircraft and apparatus patent applications designed for cargo operations were utilized

Challenges in Additive Manufacturing Technology: Post Processing, Design and Material’s Selection

It is important to bear in mind that additive manufacturing (AM) did not emerge in isolation but rather built upon earlier technologies. The rapid adoption of 3D printing technology across industries serves as a testament to its effective evolution from a specialized method primarily used for prototyping to a viable industrial production technique. As the trend continues to gain momentum, an increasing number of companies will inevitably embrace AM techniques to manufacture components using diverse materials. This chapter explores significant milestones in the history of additive manufacturing, illustrating the advancements 3D printing has made over the past decade while considering the widespread growth of applications and technology in the mainstream. The transformative journey of 3D printing is examined, shedding light on its profound impact on various industries and its potential for further development and innovation in the future. By examining the historical context and current landscape, this chapter aims to provide a comprehensive understanding of the progressive nature of additive manufacturing and its continued role in shaping the manufacturing industry. In Sect. 1, a brief introduction is given regarding the historical and future trends in additive manufacturing. Sections 2–6 discuss different additive manufacturing techniques, their working principles, and the suitable materials for each of these techniques. In Sect. 7, the concept of 4D printing is briefly discussed, including its applicability and future trends. © 2024, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd

Vibratory Surface Finishing of Additive Components Prepared from the Laser Powder Bed Fusion Process

Traditionally seen as a promising technology for producing small, lowquality prototypes, 3D printing is widening its potential by becoming faster and more dependable. Instead of cutting a shape from a bigger block or casting a molten material in a mould, 3D printing entails adding items layer by layer, making the process more cost-effective and material-efficient

Evolution of Temperature and Residual Stress Behavior in Selective Laser Melting of 316L Stainless Steel Across a Cooling Channel

Purpose – The current investigation aims at observing the influence of the cooling channel on the thermal and residual stress behavior of the selective laser melting (SLM)316L uni-layer thermo-mechanical model. Design/methodology/approach – On a thermo-mechanical model with a cooling channel, the effect of scanning direction, parallel and perpendicular and scan spacing was simulated. The effect of underlying solid and powder bases was evaluated on residual stress profile and thermal variables at various locations. Findings – The high heat dissipation of solid base due to high cooling rates and steep thermal gradients can reciprocate with smaller melt pool temperature and melt pool size. Given the same scan spacing, residual stresses were found lower when laser scanning was perpendicular to the cooling channel. Moreover, large scan spacing was found to increase residual stresses. Originality/value – Cooling channels are increasingly being used in additive manufacturing; however, their effect on the residual stress behavior of the SLM component is not extensively studied. This research can serve as a foundation for further inquiries into the impact of base material design such as cooling channels on manufactured components using SLM

Pseudo‑Relevance Feedback Based Query Expansion Using Boosting Algorithm

Retrieving relevant documents from a large set using the original query is a formidable challenge. A generic approach to improve the retrieval process is realized using pseudo-relevance feedback techniques. This technique allows the expansion of original queries with conducive keywords that returns the most relevant documents corresponding to the original query. In this paper, five different hybrid techniques were tested utilizing traditional query expansion methods. Later, the boosting query term method was proposed to reweigh and strengthen the original query. The query-wise analysis revealed that the proposed approach effectively identified the most relevant keywords, and that was true even for short queries. All the proposed methods’ potency was evaluated on three different datasets; Roshni, Hamshahri1, and FIRE2011. Compared to the traditional query expansion methods, the proposed methods improved the mean average precision values of Urdu, Persian, and English datasets by 14.02%, 9.93%, and 6.60%, respectively. The obtained results were also established using analysis of variance and post-hoc analysis

Post-Processing in Additive Manufacturing Requirements, Theories, and Methods

3D printing has always been seen as a promising technology for creating small, lowquality prototypes. As it is getting faster and more dependable, its applications are becoming more diversified. 3D printing involves adding components layer by layer using only raw material and energy source, which is more economical and efficient with materials than cutting a shape from a larger block or pouring molten material into a mold [1–3]. In recent years, the commercial market for 3D printers has rapidly expanded thanks to an unprecedented development in materials and printing techniques, making it more diversified and highly competitive [3, 4]. With 3D printing’s quick and simple design process, it is now possible to customize a wide variety of materials for different applications, making the development of unique products a reality that was previously only a pipe dream with milling or casting. The schematic representation of an LPBF operation is given in Figure 4.1

Parameters Optimization for Horizontally Built Circular Profiles: Numerical and Experimental Investigation

Selective laser melting (SLM), a type of additive manufacturing (AM) process, is chosen for direct fabrication of powder-based functional metallic objects. The designing of small circular geometries or overhang surfaces built parallel to platform bed has been a subject of concern in the industrial application of SLM. This paper presents an attempt to design and fabricate horizontally built circular holes in a simple cubic model in SLM machine. The processing parameters for down-skin such as laser power, scan speed, and the number of scanned layers were found to play a significant role in the sustainability of small hole built without support structures. The lower incident energy in down-skin region prevents excess melting of powder particles. The Numerical study on ANSYS was first carried out to identify the melt pool depth with different processing parameters and later SLM machine was used to produce the specimens for visual inspection. The results were found satisfactory with the application of down-skin parameters (65W, 1000mm/s) subjected to scanning of 3-5 layers above the exposed surface