Solid Lubricants in Ti-6Al-4V

BY –ANOOP KR. AGARWAL, AVNISH GAUR, ROHIT GOTHWAL

INTRODUCTION• Topic - Study of Solid Lubricants In Surface Grinding of

Titanium Alloys.

• Technique – Sandwich Grinding

• Alloy – Ti-6Al-4V

• Problem – Replace fluid coolants due to cost, air barrier, film boiling, etc.

• Approach – Reduce heat at its generation stage rather than removing the heat after its generation.

OBJECTIVES• Identify some Solid Lubricants, which can sustain and provide lubrication over a wider range of

temperatures.

• Development of three such wheels with varying number of slots for lubricant sandwiching.

• Study and analyze performance of these wheels and compare to conventional wheel in Dry Grinding.

• To study – Normal Force(Fn), Tangential Force(Ft), Grinding Force Ratio(Ft/Fn), Surface Roughness(Ra), and Intermittent work piece surface profiles and force pattern in continuous grinding test.

• Factors – Number of Slots, Type of Lubricant.

• Force measurements using a 3-component piezoelectric dynamometer.

• Surface roughness (Ra) of the ground part and its profiles using a Talysurf.

WORK PLAN & GANTT. CHARTTask % Done Sep. 01-07 Sep. 08-20 Sep. 20-25 Sep.26-

Oct. 15 Oct. 15- 31 Nov. 18 Nov. 815

Study research papers. -

Selection of Solid Lubricants

100

Design Grinding Wheel 100

Purchase 100

Develop sandwiched wheel.

100

Compare and analyse 0

Most efficient solution 0

Final observations 0

PROGRESS MADE

• First step was to study the process and decide the work plan. Gantt Chart was made accordingly and the stages were successfully executed.

• Choice of Sandwich Grinding technique for grinding process, among options like Taguchi method, Response Surface Method, etc.

• Criteria – Unexplored but the one which has potential and easily applicable.

• Deciding the process parameters & criteria for performing our experiments. Selection of Solid Lubricants.

EXPERIMENT PARAMETERS

• The idea was to create a design with required strength so that the wheel does not break but has enough clearance to provide appropriate lubrication.

• From those designs, we chose the ones which were practically feasible (could be cut) in the market.

• Final design was done considering specific geometry and tapering.

DESIGNING GRINDING WHEEL

PROGRESS MADE CUTTING THE WHEEL

• Most time consuming step in our project.

• Initial techniques considered were among Water Jet Machining, Diamond tool cutting, etc.

• Cutting was done using Diamond Cutter.

• Slots were cut at equal spacing, extending radially inward.

• More width was given to the slot at the inner side so that the taper formed at the slots converged towards the wheel periphery.

• The inner edge of the slots was given a radius.

Solid LubricantsGRAPHITE MOLYBDENU DISULPHIDE CALCIUM FLUORIDE

1 Fixed carbon: 80%-99.9% 2 Particle size:-300mesh 3 Moisture: 0.5%max

Size: 1.5um300 mesh flakesProperty: Pure grey powderParticle Size:-300mesh

Low SiO2 content.CaF2:98%, CaCO3:<1, Fe2O3:<0.03, Al2O3:<0.2, SiO2:<1, S:<0.02

SODIUM SULPHATE

Lubricant filler used with Graphite.

Development of Sandwiched Wheel

• After several trials, we concluded that lubricant filler, taken in a suitable composition, could be resin bonded with graphite in the slots.

• Composition by weight- 45% of fine graphite powder 55% of a mixture of sodium phosphate and sodium sulphate

in 30:70 by parts.

• The wheel is now ready for experimentation.