Determine the carburizing time, t, necessary to achieve a carbon concentration of 0.45 wt% at a position of 2mm into an iron-carbon alloy that initially contains 0.20 wt% c. the surface concentration is to be maintained at 1.30 wt% c, and the treatment is to be conducted at 1000 ℃. diffusion data is for -fe (austenite).

Afull journal bearing has a journal diameter of 27 mm, with a unilateral tolerance of -0.028 mm. the bushing bore has a diameter of 27.028 mm and a unilateral tolerance of 0.04 mm. the l/d ratio is 0.5. the load is 1.3 kn and the journal runs at 1200 rev/min. if the average viscosity is 50 mpa-s, find the minimum film thickness, the power loss, and the side flow for the minimum clearance assembly.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Burgers vector is generally parallel to the dislocation line. a)-true b)-false