Extrusion is a very popular and multi-faceted manufacturing process. A large number of products for the automotive, aerospace, and construction sectors are produced through aluminum extrusion. Many defects in the extruded products occur because of the conditions of the dies and tooling. The problems in dies can be due to material issues, design and manufacturing, or severe usage. They can be avoided by maintaining the billet quality, by controlling the extrusion process parameters, and through routine maintenance. Die problems that occur on a day-to-day basis are mostly repairable and are rectified through various types of die correction operations. These defects and repair operations have not been reported in detail in the published literature. The current paper presents an in-depth description of repairable die defects and related die correction operations in metal extrusion. All major die defects are defined and classified, and their causes, preventive measures, and die correction operations are described. A brief frequency-based statistical study of die defects is also carried out to identify the most frequent die corrections. This work can be of direct benefit to plant engineers and operators and to researchers and academics in the field of metal extrusion.

Growing energy demand is forcing the petroleum industry to reevaluate resources found in unconventional gas formations and utilizing low-production zones. Extracting oil and gas from these difficult and deep reservoirs require new knowledge which should lead to develop solutions in lifting those reserves to the surface. Centuries-old manufacturing process of tube forming has found an interesting and extended application in petroleum well drilling and delivery. The in-situ expansion of tube is aimed at expanding its diameter by pushing or pulling a mandrel through it. The expansion process is strongly nonlinear due to material and contact nonlinearities. The goal is to achieve desired tube expansion smoothly as well as maintain minimum post expansion material and mechanical properties. The objective of this research is to conduct experiments to expand the tube under simulated downhole conditions. Finite element analysis is also used to simulate the expansion process, and the results are compared with experimental data. The force required for expanding the tube, thickness reduction in tube wall thickness, and length shortening under fixed-free end condition are estimated. Good agreements were found between numerical and experimental results. Thickness reduction greater than 12% lowers collapse strength by 50% making it unsuitable for deep wells.

Among the critical issues dictating bio-composite performance is the interfacial bonding between the natural fibers and polymer matrix. In this regard, this article presents new synthesis routes comprising the treatment and functionalization of both date palm powder (DPP) filler and a polypropylene (PP) matrix to enhance filler–polymer adhesion in the newly developed bio-composites. Specifically, four bio-composite forms are considered: untreated DPP filled PP (DPP-UT/PP), treated DPP filled PP (DPP-T/PP), treated DPP filled functionalized PP using 2-isocyanatoethyl methacrylate (DPP-T/PP-g-IEM), and treated and functionalized DPP using 4-toluenesulfonyl chloride filled functionalized PP using 2-acrylamide ((DPP-T)-g-TsCl/PP-g-AcAm). The functional groups created on the surface of synthesized PP-g-IEM react with activated hydroxyl groups attached to the filler, resulting in chemical crosslinking between both components. Similarly, the reaction of TsCl with NH₂ chemical groups residing on the mating surfaces of the filler and polymer generates an amide bond in the interface region. Fourier transform infrared spectroscopy (FTIR) is used to confirm the successful coupling between the filler and polypropylene matrix after applying the treatment and functionalization schemes. Owing to the introduced crosslinking, the DPP-T/PP-g-IEM bio-composite exhibits the best mechanical properties as compared to the neat polymer, unfunctionalized polymer-based bio-composite, and (DPP-T)-g-TsCl/PP-g-AcAm counterpart. The applied compatibilizers assist in reducing the water uptake of the manufactured bio-composites, increasing their durability.

In the last decade, traditional tube expansion process has found an innovative application in oil and gas wells drilling and remediation. The ultimate goal is to replace the conventional telescopic wells to monodiameter wells with minimum cost, which is still a distant reality. Further to this, large diameters are needed at terminal depths for enhanced production from a single well while keeping the power required for expansion and related costs to a minimum. Progress has been made to realize slim wells by driving a rigid mandrel of a suitable diameter through the tube either mechanically or hydraulically to attain a desirable expansion ratio. This paper presents a finite element model, which predicts the drawing force for expansion, the stress field in expanded and pre-/postexpanded zones, and the energy required for expansion. Through minimization of energy required for expansion, an optimum mandrel configuration, i.e., shape, size, and angle, was obtained, which can be used to achieve larger in situ expansion. It is found that mandrel with elliptical, hemispherical, and curved conical shapes has minimum resistance during expansion as compared to the widely used circular cross section mandrel with a cone angle of 10 deg. However, further manipulation of shape parameters of the circular cross section mandrel yielded an improved efficiency. The drawing force required for expansion reduces by 7–10% having minimum dissipated energy during expansion. It is also found that these mandrels yield less reduction in tube thickness after expansion, which results in higher postexpansion collapse strength. In addition, rotating a mandrel further reduces the energy required for expansion by another 7%.