Due to polymeric wear debris causing osteolysis from polymer, metal ions causing metallosis from metal, and brittle characteristic causing fracture failure from ceramic in the application on bearing of total hip prosthesis requires the availability of new material options as a solution to these problems. Polycrystalline diamond (PCD) has the potential to become the selected material for hard-on-hard bearing in view of its advantages in terms of mechanical properties and biocompatibility. The present study contributes to confirming the potential of PCD to replace metals and ceramics for hard-on-hard bearing through von Mises stress investigations. A computational simulation using a 2D axisymmetric finite element model of hard-on-hard bearing under gait loading has been performed. The percentage of maximum von Mises stress to respective yield strength from PCD-on-PCD is the lowest at 2.47%, with CoCrMo (cobalt chromium molybdenum)-on-CoCrMo at 10.79%, and Al2O3 (aluminium oxide)-on-Al2O3 at 13.49%. This confirms that the use of PCD as a hard-on-hard bearing material is the safest option compared to the investigated metal and ceramic hard-on-hard bearings from the mechanical perspective.

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Equestrian sport or horse riding is very popular because not only for sports or hobby, but also for entertainment. The performance racehorse of the is largely determined by the suitability of the characteristics of horseshoes material with horse's hooves. This paper describes the identification of materials and heat treatment process of horseshoe made in local and imported products. Previous publication suggests that horseshoe made in foreign countries provides better performance than domestic products, especially in terms of flexibility of horse motion, durability, speed, and lifetime. Therefore, it is necessary to conduct research that emphasizes the observation of material characteristics, manufacturing and heat treatment process as a first step towards the substitution of imported products. A number of observations have been made on the two types of products:macro and micro observations, heat treatment process analyzes that have been subjected to materials, and mechanical testing. From the test results obtained that imported horseshoe material is low carbon steel with of 0.08 %, while carbon content for local product is 0.17%. Thus, both from the material side and from the side of manufacturing, including heat treatment process, local horseshoe products still need to be developed.

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This paper presents the results of advanced work as a continuation of previous observations about the identification of material and process of the horseshoe fabrication for racehorses as published in the “Jurnal Poros Vol. 15 No. 2, November 2017”. This further research is more focused on the evolution of microstructure and the value of hardness as a function of deformation degree variations of the forging process for horseshoes and horse nails. This is performed to investigate how much degree of deformation can produce form, type and phase distribution on the microstructure and the value of hardness that are relevant to the characteristics of imported products. Through this stage, the material characteristics of imported products can be approached and obtained from the local products. Thus, the quality of horseshoes and horse nails similar to imported products are expected to be able to fabricate in the local SME (Small Medium Enterprise). From the microstructure aspect, there are differences in grain shapes for Local, Australian and Swedish products because the grain forms fabricated in Sweden and Australia are more elongated than local products. This represents that the value of hardness is higher than local products except products fabricated in Australia. Local product nails have better grain because they are more equiaxial and have finer grains so that they have a high hardness value and better toughness compared to imported products. Local horseshoe show a much lower value of hardness compared to imported products. There is a peculiarity in the horseshoe because the hardness value decreases when the degree of deformation increases that is from the percentage of the work process 20% to 80%. From the microstructure of the horseshoe, the increasing deformation degree of the work process percentage 20% to 80%, the grain size is coarser and the grain size is smoother back when the percentage of the work process reaches 100%. This is proven when the percentage of the work process reaches 100%, the value of hardness increases to 147 VHN.