Experimentation Investigation of Hard facing Layer by MMAW on Alloy Steel

The wearing of metal parts might be defined as a gradual decay or breakdown of the metal. When a part becomes so deformed that it cannot perform adequately, it must be replaced or rebuilt. While the end results of wear are similar, the causes of wear are different. It is essential to understand the wear factors involved before making a hard surfacing product selection. It would be easy to select a surfacing alloy if all metal components were subjected to only one type of wear. However, a metal part is usually worn by combinations of two or more types of wear. This makes an alloy selection considerably more complicated. A hard surfacing alloy should be chosen as a compromise between each wear factor. The initial focus should centre on the primary wear factor and then the secondary wear factor(s) should be examined. For example: upon examining a worn metal part, it is determined that the primary wear factor is abrasion and the secondary wear factor is light impact. The surfacing alloy chosen should have very good abrasion resistance but also have a fair amount of impact resistance. Keywords: Welding, Hard Facing Electrodes, Alloys, Afrox 300.

The Experimental Investigation of Punching of the AM60 and AZ61 Magnesium Alloy Sheets by Using Varied Punch Shapes

The using of magnesium alloys for industrial sheet metal part production has become increasingly common in recent years. This research aims to characterize the effects of the cutting-edge shapes of the punches on the blanking forces and the sheared edge qualities in the blanking/piercing operations of magnesium alloy sheets. Magnesium sheets (AM60 and AZ61) were produced by casting and rolling processes. AM60 and AZ61 Mg alloys produced by casting were rolled by using two different speeds, 2.5 m/min and 7.5 m/min. Material thickness was adjusted to three mm in the rolling process. Blanking tests were carried out on a die-set and hydraulic press by varying shaped punches. In the experimental studies, flat-ended, concave shaped, and 16° angled punches were used. A loadcell was fixed to the experimental setup to determine the blanking forces. The results showed that the AM60 alloy was more resistant to shearing than the AZ61. The lowest blanking force was obtained by use of the 16° angled punch. It was determined that the using of flat-ended punches for blanking operations was more convenient according to the usage purpose of the parts while all three punches can be used for piercing operations.

Recovery of Latent Fingermarks on Metal Part of Motorcycle Submerged in Different Aquatic Environments

Motorcycle theft cases in Malaysia have increased quite significantly with more motorcycles were reported stolen every day. In many cases, criminals had removed the components they only required and disposed the remaining parts into various sources of water. Unfortunately, the evidence recovered underwater was thought not to have forensic value with regards to fingermark recovery. This study aimed to determine the survivability of the latent fingermarks submerged in various water environments. Latent fingermarks were deposited on metal parts of motorcycle and submerged into four aquatic environments; river, lake, mine, and tap water for two weeks with time intervals for collection of 1, 8, 24, 48, 96, 168, and 336 h. Upon recovery, the fingermark samples were developed using Small Particle Reagent (SPR). The developed fingermarks were assessed using Biometric Fingerprint Identification System (BIOFIS). The persistence of fingermarks immersed in tap water was found to last up to more than two weeks. Contrarily, fingermark in other water environments can only survive up to 96 h after being submerged. The fingermarks submerged in the lake appeared to be better preserved as compared to those submerged in the river and mine. The development of underwater fingermarks is still feasible, and identifiable fingermarks can still be recovered at the early submersion period.

Sample Printing Device for Additive Manufacturing of Electronic Housings

This work presents the results of work on a 3D printing device with a non-standard arrangement of the table and nozzle, which is necessary for the additive production of plastic cases for electronic devices. The non-standard arrangement of the table is caused by the need to use special accessories to hold third-party embedded elements of the case. A metal part - a contactor - is used as an embedded element. Due to the specific mortgage they made, as well as the experimental equipment, the authors came to the conclusion that it is economically more expedient to design and manufacture a prototype 3D printer than to modify the existing device. A sample of the FDM printing device was designed, manufactured and tested.

OPTIMIZATION OF THE THERMAL PROCESS OF ABRASIVE METAL WORKING

The main problem that arises from grinding metal is the generation of a large amount of heat. Exceeding a critical temperature will damage the part. However, determining the heat of the metal being processed is a difficult task both practically and theoretically. The correct choice of parameters for the abrasive processing is essential to obtain the required quality. This article describes a mathematical model that simulates the determination of the maximum heat on the surface of a metal part during grinding. This model features the ability to change the initial parameters so that the resulting temperature does not exceed the critical one. The model has been tested by a specially developed web application written in JavaScript. It not only calculates the highest temperature in the machining zone of the workpiece, but also optimizes the thermal grinding process to give appropriate recommendations. The features of such a program are disclosed, including its practical use in production.

Improvement on QFN Leadframe Design of Extended Leads to Support the Mitigation of Mold Flash Occurrence

Parameter optimization is not only the key to find the most favorable and best solution as variable chances of failure modes may happen at extreme case conditions at unexpected period. Packaging design robustness is much resilient to establish a satisfactorily good quality product and sustain a long-term goal of a remarkable process capability. This paper presents leadframe design solution of quad-flat no leads (QFN) to address mold flash defect caused by leadframe bouncing during wirebonding. An inverted pyramid configuration was conceptualized to provide better stability than the standard configuration during wirebonding process and other concerned assembly processes due to the shift of the center of gravity moving closer to the full metal part.

Direct Laser Deposition for Tailored Structure

In the context of Industry 4.0, interest is increasing towards Additive Manufacturing processes due to their several advantages. Among these, the Direct Laser Deposition (DLD) is an innovative technology for additive metal part fabrication, and it is currently demonstrating its ability to revolutionize the manufacturing industry. It is particularly interesting for industrial applications in terms of reduction of waste materials by starting with fewer feedstocks, reduction of machining time by only have material where it is needed but, above all, it is interesting to extend the life of parts. Indeed, with the DLD, it is possible to repair an item or coat parts via cladding, making it more wear-resistant. It is also possible to give "another life" to broken or waste components, for example, by replacing the damaged area using new material. Moreover, particularly intriguing is the possibility to create hybrid or graded parts by varying material/alloy concentrations. This paper aims to combine the abovementioned advantages to develop tailored structures in order to accomplish complex and functional products. For this purpose, a specific case study was investigated, starting with the study of the appropriate powders to use and ending with the printing process using the DMG Mori Lasertec65. Microstructural and mechanical analyses were carried out to evaluate the products and to validate the process. The final results show the properties and performances of products obtained using this technology.