# Effect of Ti-B Grain Refiners on Wear and Corrosion of the A332 Alloy with Sr Modification
## 1 Introduction
The ratio between Ti/B in master alloys and the way of processing conditions lead to a different morphology of the Al\({}_{3}\)Ti particles, which may have resulted from different growth mechanisms [11]. The effectiveness and mechanisms of grain refiners might be altered by introducing different methods and temperatures. [PERSON] et al. [12] evaluated the influence of melting temperatures of 800 \({}^{\circ}\)C and 650 \({}^{\circ}\)C in the Al7 Si refined with Al10 Ti. Image analyses of optical micrographs led to the characterization of the grain refiner particles in the Al10 Ti master alloy and the sediment layers formed during the experiments. When the master alloy was added at a constant 690 \({}^{\circ}\)C, undissolved blocky particles settled at the bottom. In this case, grain refinement was not accomplished. In the meantime, an effective grain refinement when the grain refiner was first dissolved at 800 \({}^{\circ}\)C and re-precipitated at 690 \({}^{\circ}\)C, showing the importance of using appropriate temperatures. Similar results were observed in other works. Modifications and grain refiners were applied to achieve desired properties. Nevertheless, adding grain refiners may produce undesirable effects. [PERSON] and [PERSON] [13] studied the impact of the Al-Ti-B grain refiner on the fatigue mechanism of the A332 aluminum alloy. The results show a different concentration of Ti and B through the sample, which affects the properties. The difference in density of both particles (Al\({}_{3}\)Ti and TiB\({}_{2}\)) is the primary factor affecting the fading mechanism. Thus, carefully inserting materials in the molten material is essential to have an effective action in the aluminum alloy. Other studies have suggested that the grain refiner addition promotes changes in microstructural features and directly relates to mechanical properties. [PERSON] et al. [14] evaluated the variation of wt% of Al5 Ti1B grain refiner on the microstructural features of Al7 Si alloy. X-ray diffraction (XRD), scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), and thermodynamic analysis were used. The morphology of primary aluminum grain changes from a coarse dendritic structure to a fine equiaxed grain. The eutectic phase was also refined, and the presence of an iron-based intermetallic was observed. From mechanical properties, the grain refiner addition took an increase in hardness and yield strength. The refined alloy's fracture mechanism changed from brittle to ductile fracture. Albeit elongation decreased when the percentage of Ti increased by more than 0.1 wt.%. The combined action of Al5 Ti1B grain refiner with Al10 Sr modifier may show better results than only using the grain refiner. [PERSON] [15] used grain refining (Al5 Ti1B) and modifier (Al10 Sr) to determine the effect of modification and grain refining on the microstructure and mechanical properties of A356 aluminum alloy. It was concluded that the sharp-edged morphology of the eutectic phase tended to be spherical with Sr addition. Furthermore, the porosity was reduced, increasing Al5 Ti1B up to 1.5 wt.%. In addition, the presence of Al5 Ti1B promotes an increased average ultimate tensile strength, and the percentage of elongation increases as well. The grain refiner's efficiency was also tested with distinct Al-Si alloys and molds. [PERSON] and [PERSON] [16] evaluate the effects of Al5 Ti1B grain refiner and Al10 Sr modifier additives on friction and wear properties on A380 and A357 alloys, using the pin-disk test. Their results show that grain refiner and modifier additives decrease the friction coefficient and increase the wear resistance, headlining the need for studying several combinations of the alloy, grain refiner, and modifier. [PERSON] et al. [17] researched the wear behavior of cast Al16 Si alloy with five different compositions of Al5 Ti1B grain refiner, Al5 Sr modifier, and graphene. An evident transformation of eutectic silicon to rounded particles can be observed through the microstructural analysis.