A method and apparatus for deep penetration deposition of material in a porous substrate utilizes a pressure differential across the substrate to effect penetration of arc-produced vapor from one chamber through the body. The one chamber can be held at a pressure of 10.sup.-2 to 10.sup.-3 torr while the other chamber is at a pressure of 10.sup.-5 to 10.sup.-6 torr.

A liquid coating method for coating a liquid onto inner cells of a honeycomb structure includes the steps of supplying a liquid to the inside of a honeycomb structure vertically arranged from its lower part to cause the liquid to adhere to the inner cells therein, and supplying pressurized air to an upper part of the honeycomb structure to discharge the liquid within the inner cells. A holding apparatus for holding an article includes an outer cylinder in a form of a pipe having an inner wall with an inner diameter which allows an article to be held to pass therethough easily and which has a sufficient strength, a resilient tube having an inner diameter which prevents the article to be held from passing therethough under no tension and having ends each sealingly connected to the outer cylinder, thus defining together with the inner wall of the outer cylinder sealed space therebetween, means for discharging a fluid from the sealed space; and means for supplying the fluid to the sealed space.

A liquid coating method for coating a liquid onto inner cells of a honeycomb structure includes the steps of supplying a liquid to the inside of a honeycomb structure vertically arranged from its lower part to cause the liquid to adhere to the inner cells therein, and supplying pressurized air to an upper part of the honeycomb structure to discharge the liquid within the inner cells. A holding apparatus for holding an article includes an outer cylinder in a form of a pipe having an inner wall with an inner diameter which allows an article to be held to pass therethough easily and which has a sufficient strength, a resilient tube having an inner diameter which prevents the article to be held from passing therethough under no tension and having ends each sealingly connected to the outer cylinder, thus defining together with the inner wall of the outer cylinder a sealed space therebetween, means for discharging a fluid from the sealed space; and means for supplying the fluid to the sealed space.

A method of producing a hydroxylapatite base porous beads filler for an organism, including mixing hydroxylapatite powder having particle sizes not larger than 125 .mu.m, in an amount ranging from 40 to 90% by weight, synthetic resin powder having particle sizes not larger than 74 .mu.m, in an amount ranging from 5 to 55% by weight, and resinous binder in an amount ranging from 0.5 to 5% by weight to obtain a mixture, granulating the mixture to form beads each having a diameter ranging from 0.03 to 25 mm, firing the beads at a temperature ranging from 900.degree. C. to 1180.degree. C. to form hydroxylapatite base porous beads, dipping the porous beads in a colloidal solution, removing air from the porous beads under vacuum, and filling the colloidal solution into the pores in the porous beads under pressure.

A machine for impregnating a die cast metal part with liquid impregnant comprises an impregnation chamber having liquid impregnant in a lower portion, an opening for ingress and egress of the parts being defined in a side wall of the chamber above the liquid impregnant, a door for sealing the opening, a part holder in the chamber and an elevator for positioning parts above the liquid impregnant during evacuation of the chamber and then immersing the parts in the liquid impregnant during subsequent pressurization of the chamber.